Aviation and Climate Change
Aircraft Emissions Expected to Grow, but Technological and Operational Improvements and Government Policies Can Help Control Emissions Gao ID: GAO-09-554 June 8, 2009Aircraft emit greenhouse gases and other emissions, contributing to increasing concentrations of such gases in the atmosphere. Many scientists and the Intergovernmental Panel on Climate Change (IPCC)--a United Nations organization that assesses scientific, technical, and economic information on climate change--believe these gases may negatively affect the earth's climate. Given forecasts of growth in aviation emissions, some governments are taking steps to reduce emissions. In response to a congressional request, GAO reviewed (1) estimates of aviation's current and future contribution to greenhouse gas and other emissions that may affect climate change; (2) existing and potential technological and operational improvements that can reduce aircraft emissions; and (3) policy options for governments to help address commercial aircraft emissions. GAO conducted a literature review; interviewed representatives of government agencies, industry and environmental organizations, airlines, and manufacturers, and interviewed and surveyed 18 experts in economics and aviation on improvements for reducing emissions from aircraft. GAO is not making recommendations. Relevant agencies provided technical comments which we incorporated as appropriate and EPA said emissions standards can have a positive benefit to cost ratio and be an important part of policy options to control emissions.
According to IPCC, aviation currently accounts for about 2 percent of human-generated global carbon dioxide emissions, the most significant greenhouse gas--and about 3 percent of the potential warming effect of global emissions that can affect the earth's climate, including carbon dioxide. IPCC's medium-range estimate forecasts that by 2050 the global aviation industry, including aircraft emissions, will emit about 3 percent of global carbon dioxide emissions and about 5 percent of the potential warming effect of all global human-generated emissions. Gross domestic product growth is the primary driver in IPCC's forecasts. IPCC also made other assumptions about future aircraft fuel efficiency, improvements in air traffic management, and airport and runway capacity. IPCC's 2050 forecasts for aviation's contribution to global emissions assumed that emissions from other sectors will continue to grow. If other sectors make progress in reducing emissions and aviation emissions continue to grow, aviation's relative contribution may be greater than IPCC estimated; on the other hand, if other sectors do not make progress, aviation's relative contribution may be smaller than estimated. While airlines currently rely on a range of improvements, such as fuel-efficient engines, to reduce emissions, some of which may have limited potential to generate future reductions, experts we surveyed expect a number of additional technological, operational, and alternative fuel improvements to help reduce aircraft emissions in the future. However, according to experts we interviewed, some technologies, such as advanced airframes, have potential, but may be years away from being available, and developing and adopting them is likely to be costly. In addition, according to some experts we interviewed, incentives for industry to research and adopt low-emissions technologies will be dependent to some extent on the level and stability of fuel prices. Finally, given expected growth of commercial aviation as forecasted by IPCC, even if many of these improvements are adopted, it appears unlikely they would greatly reduce emissions by 2050. A number of policy options to address aircraft emissions are available to governments and can be part of broader policies to address emissions from many sources including aircraft. Market-based measures can establish a price for emissions and provide incentives to airlines and consumers to reduce emissions. These measures can be preferable to other options because they would generally be more economically efficient. Such measures include a cap-and-trade program, in which government places a limit on emissions from regulated sources, provides them with allowances for emissions, and establishes a market for them to trade emissions allowances with one another, and a tax on emissions. Governments can establish emissions standards for aircraft or engines. In addition, government could increase government research and development to encourage development of low-emissions improvements.
GAO-09-554, Aviation and Climate Change: Aircraft Emissions Expected to Grow, but Technological and Operational Improvements and Government Policies Can Help Control Emissions
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Report to Congressional Committees:
United States Government Accountability Office:
GAO:
June 2009:
Aviation And Climate Change:
Aircraft Emissions Expected to Grow, but Technological and Operational
Improvements and Government Policies Can Help Control Emissions:
GAO-09-554:
GAO Highlights:
Highlights of GAO-09-554, a report to congressional committees.
Why GAO Did This Study:
Aircraft emit greenhouse gases and other emissions, contributing to
increasing concentrations of such gases in the atmosphere. Many
scientists and the Intergovernmental Panel on Climate Change (IPCC)”a
United Nations organization that assesses scientific, technical, and
economic information on climate change”believe these gases may
negatively affect the earth‘s climate. Given forecasts of growth in
aviation emissions, some governments are taking steps to reduce
emissions. In response to a congressional request, GAO reviewed (1)
estimates of aviation‘s current and future contribution to greenhouse
gas and other emissions that may affect climate change; (2) existing
and potential technological and operational improvements that can
reduce aircraft emissions; and (3) policy options for governments to
help address commercial aircraft emissions.
GAO conducted a literature review; interviewed representatives of
government agencies, industry and environmental organizations,
airlines, and manufacturers, and interviewed and surveyed 18 experts in
economics and aviation on improvements for reducing emissions from
aircraft.
GAO is not making recommendations. Relevant agencies provided technical
comments which we incorporated as appropriate and EPA said emissions
standards can have a positive benefit to cost ratio and be an important
part of policy options to control emissions.
What GAO Found:
According to IPCC, aviation currently accounts for about 2 percent of
human-generated global carbon dioxide emissions, the most significant
greenhouse gas”and about 3 percent of the potential warming effect of
global emissions that can affect the earth‘s climate, including carbon
dioxide. IPCC‘s medium-range estimate forecasts that by 2050 the global
aviation industry, including aircraft emissions, will emit about 3
percent of global carbon dioxide emissions and about 5 percent of the
potential warming effect of all global human-generated emissions. Gross
domestic product growth is the primary driver in IPCC‘s forecasts. IPCC
also made other assumptions about future aircraft fuel efficiency,
improvements in air traffic management, and airport and runway
capacity. IPCC‘s 2050 forecasts for aviation‘s contribution to global
emissions assumed that emissions from other sectors will continue to
grow. If other sectors make progress in reducing emissions and aviation
emissions continue to grow, aviation‘s relative contribution may be
greater than IPCC estimated; on the other hand, if other sectors do not
make progress, aviation‘s relative contribution may be smaller than
estimated.
While airlines currently rely on a range of improvements, such as fuel-
efficient engines, to reduce emissions, some of which may have limited
potential to generate future reductions, experts we surveyed expect a
number of additional technological, operational, and alternative fuel
improvements to help reduce aircraft emissions in the future. However,
according to experts we interviewed, some technologies, such as
advanced airframes, have potential, but may be years away from being
available, and developing and adopting them is likely to be costly. In
addition, according to some experts we interviewed, incentives for
industry to research and adopt low-emissions technologies will be
dependent to some extent on the level and stability of fuel prices.
Finally, given expected growth of commercial aviation as forecasted by
IPCC, even if many of these improvements are adopted, it appears
unlikely they would greatly reduce emissions by 2050.
A number of policy options to address aircraft emissions are available
to governments and can be part of broader policies to address emissions
from many sources including aircraft. Market-based measures can
establish a price for emissions and provide incentives to airlines and
consumers to reduce emissions. These measures can be preferable to
other options because they would generally be more economically
efficient. Such measures include a cap-and-trade program, in which
government places a limit on emissions from regulated sources, provides
them with allowances for emissions, and establishes a market for them
to trade emissions allowances with one another, and a tax on emissions.
Governments can establish emissions standards for aircraft or engines.
In addition, government could increase government research and
development to encourage development of low-emissions improvements.
To view the full product, including the scope and methodology, click on
[hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-09-554]. For more
information, contact Susan Fleming at (202) 512-2834 or
flemings@gao.gov.
[End of section]
Contents:
Letter:
Background:
Aviation Emissions Represent a Small but Growing Share of All
Emissions:
Experts Believe Future Technological and Operational Improvements Are
Likely to Help Reduce Emissions from Commercial Aircraft, but Likely
Not by Enough to Fully Offset Estimated Market Growth:
Governments Can Use a Variety of Policy Options to Help Reduce
Commercial Aircraft Emissions, but the Costs and Benefits of Each Vary:
Agency Comments and Our Evaluation:
Appendix I: Legal Implications of European Union Emissions Trading
Scheme:
Appendix II: List of Experts:
Appendix III: Detailed Survey Results:
Part 1: Technology Options:
Part 2: Operational Options:
Part 3: Alternative Fuel Options:
Appendix IV: Scope and Methodology:
Appendix V: Comments from the National Aeronautics and Space
Administration:
Appendix VI: Comments from the Environmental Protection Agency:
Appendix VII: GAO Contact and Staff Acknowledgments:
Tables:
Table 1: Types of Aviation Emissions and Their Effects at Cruising
Altitude:
Table 2: Selected Potential Aircraft Engine Improvements to Reduce
Emissions:
Table 3: Selected Aircraft Improvements to Reduce Emissions:
Table 4: Selected Operational Improvements to Reduce Emissions:
Table 5: Selected Air Traffic Management Improvements to Reduce
Emissions:
Table 6: NASA's Subsonic Fixed-Wing Research Fuel-Reduction Goals:
Figures:
Figure 1: Selected Greenhouse Gas and Other Emissions from Aircraft at
Cruising Altitude:
Figure 2: Total Fuel Consumption and Fuel Efficiency of U.S. Airlines:
Figure 3: Energy use per Passenger-mile, by Mode of Transportation:
Figure 4: Forecasted Fuel Consumption by U.S. Airlines:
Figure 5: Global Transportation's and Global Aviation's Contributions
to Carbon Dioxide Emissions, 2004:
Figure 6: Estimated Relative Contribution of Aviation Emissions to
Positive Radiative Forcing:
Figure 7: Changes in Global and U.S. Aviation Passenger Traffic, 1978
through 2008:
Figure 8: IPCC's Scenarios for Global Aviation Carbon Dioxide
Emissions:
Figure 9: A Potential Cap-and-Trade Program Regulating Airlines and
Other Emissions Sources:
Abbreviations:
ACARE: Advisory Council for Aeronautics Research in Europe:
ADS-B: Automatic Dependent Surveillance-Broadcast:
ATA: Air Transport Association:
CDA: Continuous Descent Arrival:
CER: certified emissions reduction:
CO2: carbon dioxide:
DG Environment: Directorate-General of the Environment:
EEC: European Economic Community:
EPA: Environmental Protection Agency:
ERU: emission reduction unit:
EU: European Union:
EU ETS: European Union Emissions Trading Scheme:
FAA: Federal Aviation Administration:
GDP: gross domestic product:
GIACC: Group on International Aviation and Climate Change:
ICAO: International Civil Aviation Organization:
IETA: International Emissions Trading Association:
IPCC: Intergovernmental Panel on Climate Change:
NASA: National Aeronautics and Space Administration:
NextGen: Next Generation Air Transportation System:
NOx: nitrogen oxides:
RNAV: area navigation:
RNP: Required Navigation Performance:
SESAR: Single European Sky Air Traffic Management Research Program:
UNFCCC: United Nations Framework Convention on Climate Change:
[End of section]
United States Government Accountability Office:
Washington, DC 20548:
June 8, 2009:
Congressional Requesters:
Many sources, including manufacturing, residential, and transportation
sources, emit greenhouse gases that contribute to the accumulation of
these gases in the earth's atmosphere. Greenhouse gases disperse and
trap heat in the earth's atmosphere. This heat-trapping effect, known
as the greenhouse effect, moderates atmospheric and surface
temperatures, keeping the earth warm enough to support life. However,
according to the Intergovernmental Panel on Climate Change (IPCC)--a
United Nations organization that assesses scientific, technical, and
economic information on the effects of climate change--global
atmospheric concentrations of these greenhouse gases have increased
markedly as a result of human activities over the past 200 years,
contributing to a warming of the earth's climate. These trends, if
unchecked, could have serious negative effects, such as rising sea
levels and coastal flooding worldwide.
Aircraft emit a variety of greenhouse and other gases, including carbon
dioxide--the most significant greenhouse gas emitted by aircraft--and
nitrogen oxides, as well as other substances such as soot and water
vapor that are believed to negatively affect the earth's climate.
Airlines have a financial incentive to reduce carbon dioxide emissions,
as those emissions are a direct result of fuel burn, which represents a
large portion of their operating costs--about 30 percent for U.S.
airlines in 2008. Some experts expect aviation to grow at a fast rate
until 2021, when the Federal Aviation Administration (FAA) forecasts
that U.S. domestic commercial aviation will serve over 1 billion
passengers a year. While the current economic downturn could delay this
growth somewhat, experts believe that growth in the aviation sector
means greater productivity and mobility, but is also likely to increase
emissions. To counteract expected increases in emissions, many
governments and international organizations have set goals for future
emissions reductions. For example, a number of developed countries have
set a goal to reduce carbon dioxide emissions by 50 percent by 2050. In
addition, the Kyoto Protocol, an international agreement to minimize
the adverse effects of climate change, set binding targets for the
reduction of greenhouse gases for 37 industrialized countries and the
European Economic Community (EEC) to achieve during the 2008 through
2012 commitment period.[Footnote 1] Although the United States is a
signatory to the Kyoto Protocol, it is not bound by its terms or
emissions target because it has not ratified the Protocol. The Protocol
also requires industrialized nations and the EEC to pursue "limitations
or reduction of emissions of greenhouses gases— from aviation— working
through the International Civil Aviation Organization."[Footnote 2]
Finally, some governments have taken actions designed to control
aviation emissions. For example, in 2003, the European Union (EU)
established a cap-and-trade program known as the EU Emissions Trading
Scheme (EU ETS) to control carbon dioxide emissions from various energy
and industrial sectors. The EU ETS was first implemented in 2005 and
was amended in 2008 to include aviation. Beginning in 2012, the ETS
will include all covered flights into or out of an EU airport.[Footnote
3]
You asked us to provide information on aviation emissions of greenhouse
gases and other emissions that may affect climate change. To do so, we
identified (1) aviation's current and estimated future contribution to
the emissions of greenhouse gases and other emissions that may affect
climate change, (2) existing and potential future technological and
operational improvements that the commercial aviation industry can use
to reduce commercial aircraft emissions, and (3) policy options for the
U.S. government and other governments to help reduce commercial
aviation emissions and the potential costs and benefits of each option.
You also asked that we describe the EU's plans to add the aviation
industry to its existing ETS and the potential legal implications of
doing so. (See appendix I for this description.) To address these
objectives, we reviewed studies on the impact of aviation on climate
change. We also collaborated with the National Academy of Sciences to
identify and recruit experts with experience in climate change and the
aviation industry. We interviewed 18 such experts (see appendix II for
a list of the experts). After these interviews, we asked the experts to
complete a survey in which they assessed a list of options to reduce
emissions on a variety of predetermined factors, such as potential for
emissions reductions and costs (see appendix III for complete results).
In addition, we spoke with government, airline, and interest group
officials in the United States, the EU, and the United Kingdom,
focusing on commercial aviation. (See appendix IV for a more detailed
description of our scope and methodology.) We conducted our work from
March 2008 through June 2009 in accordance with generally accepted
government auditing standards. Those standards require that we plan and
perform the audit to obtain sufficient, appropriate evidence to provide
a reasonable basis for our findings and conclusions based on our audit
objectives. We believe that the evidence obtained provides a reasonable
basis for our findings and conclusions based on our audit objectives.
Background:
Emissions from a variety of human-generated sources, including
commercial aircraft, trap heat in the atmosphere and contribute to
climate change. During flight operations, aircraft emit a number of
greenhouse gas and other emissions, including carbon dioxide, nitrogen
oxides (NOx), soot, and water vapor. Figure 1 shows the primary
emissions from commercial aircraft. Carbon dioxide emissions from
aircraft are a direct result of fuel burn. For every gallon of jet fuel
burned, about 21 pounds of carbon dioxide are emitted. Reducing the
amount of fuel burned, therefore, also reduces the amount of carbon
dioxide emitted. Water vapor emissions and certain atmospheric
temperature and humidity conditions can lead to the formation of
contrails, a cloudlike trail of condensed water vapor, and can induce
the creation of cirrus clouds. Both contrails and cirrus clouds are
believed to have a warming effect on the earth's atmosphere. Aircraft
also emit other pollutants that affect local air quality. Finally,
airport operations are sources of greenhouse gas and other emissions,
which we are not examining in this report.
Figure 1: Selected Greenhouse Gas and Other Emissions from Aircraft at
Cruising Altitude:
[Refer to PDF for image: illustration]
Jet engine:
Intake of air, combined with fuel, produces combustion;
Exhaust from combustion includes:
Carbon dioxide;
Nitrogen oxides;
Water vapor;
Sulphate; and;
Soot.
Source: GAO.
[End of figure]
Historically, the commercial aviation industry has grown substantially
in the United States and worldwide and is a contributor to economic
growth. Between 1981 and 2008, passenger traffic increased 226 percent
in the United States on a revenue passenger mile basis and 257 percent
globally on a revenue passenger kilometer basis.[Footnote 4] According
to the FAA, in 2006 the civil aviation industry in the United States
directly and indirectly contributed 11 million jobs and 5.6 percent of
total gross domestic product (GDP) to the U.S. economy. Globally, the
International Air Transport Association estimated that in 2007 the
aviation industry had a global economic impact of over $3.5 trillion,
equivalent to about 7.5 percent of worldwide GDP. Recently, however,
the airline industry has experienced declining traffic and financial
losses as the result of the current recession.
The fuel efficiency of commercial jet aircraft has improved over time.
According to IPCC, aircraft today are about 70 percent more fuel
efficient on a per passenger kilometer basis than they were 40 years
ago because of improvements in engines and airframe design.[Footnote 5]
The cost of jet fuel is a large cost for airlines. In the 2008, when
global fuel prices were high, jet fuel accounted for about 30 percent
of U.S. airlines' total operating expenses, compared with 23 percent
during 2007. Fuel efficiency (measured by available seat-miles per
gallon consumed) for U.S. carriers increased about 17 percent between
1990 and 2008, as shown in figure 2. Internationally, according to the
International Air Transport Association, fuel efficiency (measured by
revenue passenger kilometers) improved 16.5 percent between 2001 and
2007. According to FAA, between 2000 and early 2008 U.S. airlines
reduced fuel burn and emissions while transporting more passengers and
cargo.
Figure 2: Total Fuel Consumption and Fuel Efficiency of U.S. Airlines:
[Refer to PDF for image: combination vertical bar and line graph]
Year: 1981;
Gallons of fuel consumed: 8.9 billion;
Gallons of fuel per available seat mile: 47.4 mpg.
Year: 1982;
Gallons of fuel consumed: 9.3 billion;
Gallons of fuel per available seat mile: 47.3 mpg.
Year: 1983;
Gallons of fuel consumed: 10 billion;
Gallons of fuel per available seat mile: 48.2 mpg.
Year: 1984;
Gallons of fuel consumed: 11.4 billion;
Gallons of fuel per available seat mile: 46.9 mpg.
Year: 1985;
Gallons of fuel consumed: 11.8 billion;
Gallons of fuel per available seat mile: 47.8 mpg.
Year: 1986;
Gallons of fuel consumed: 13.1 billion;
Gallons of fuel per available seat mile: 47.4 mpg.
Year: 1987;
Gallons of fuel consumed: 13.8 billion;
Gallons of fuel per available seat mile: 49.9 mpg.
Year: 1988;
Gallons of fuel consumed: 14.6 billion;
Gallons of fuel per available seat mile: 47.7 mpg.
Year: 1989;
Gallons of fuel consumed: 14.8 billion;
Gallons of fuel per available seat mile: 48.0 mpg.
Year: 1990;
Gallons of fuel consumed: 15.5 billion;
Gallons of fuel per available seat mile: 48.8 mpg.
Year: 1991;
Gallons of fuel consumed: 14.5 billion;
Gallons of fuel per available seat mile: 50.7 mpg.
Year: 1992;
Gallons of fuel consumed: 15.2 billion;
Gallons of fuel per available seat mile: 50.9 mpg.
Year: 1993;
Gallons of fuel consumed: 15.3 billion;
Gallons of fuel per available seat mile: 51.9 mpg.
Year: 1994;
Gallons of fuel consumed: 15.6 billion;
Gallons of fuel per available seat mile: 51.7 mpg.
Year: 1995;
Gallons of fuel consumed: 16.1 billion;
Gallons of fuel per available seat mile: 51.5 mpg.
Year: 1996;
Gallons of fuel consumed: 16.7 billion;
Gallons of fuel per available seat mile: 51.5 mpg.
Year: 1997;
Gallons of fuel consumed: 17.3 billion;
Gallons of fuel per available seat mile: 50.8 mpg.
Year: 1998;
Gallons of fuel consumed: 17.7 billion;
Gallons of fuel per available seat mile: 50.8 mpg.
Year: 1999;
Gallons of fuel consumed: 18.4 billion;
Gallons of fuel per available seat mile: 51.4 mpg.
Year: 2000;
Gallons of fuel consumed: 19.1 billion;
Gallons of fuel per available seat mile: 51.4 mpg.
Year: 2001;
Gallons of fuel consumed: 18 billion;
Gallons of fuel per available seat mile: 53.2 mpg.
Year: 2002;
Gallons of fuel consumed: 16.9 billion;
Gallons of fuel per available seat mile: 53.9 mpg.
Year: 2003;
Gallons of fuel consumed: 16.8 billion;
Gallons of fuel per available seat mile: 54.9 mpg.
Year: 2004;
Gallons of fuel consumed: 17.8 billion;
Gallons of fuel per available seat mile: 56.0 mpg.
Year: 2005;
Gallons of fuel consumed: 18.2 billion;
Gallons of fuel per available seat mile: 56.6 mpg.
Year: 2006;
Gallons of fuel consumed: 18.1 billion;
Gallons of fuel per available seat mile: 56.6 mpg.
Year: 2007;
Gallons of fuel consumed: 18.3 billion;
Gallons of fuel per available seat mile: 58.0 mpg.
Year: 2008;
Gallons of fuel consumed: 18 billion;
Gallons of fuel per available seat mile: 57.8 mpg.
Source: U.S. Department of Transportation.
[End of figure]
In addition, commercial aviation has become less energy intensive over
time--that is, to transport a single passenger a single mile uses less
energy than it previously did, measured in British thermal units. See
figure 3 showing energy intensity over time of aviation and other modes
of transportation.
Figure 3: Energy use per Passenger-mile, by Mode of Transportation:
[Refer to PDF for image: multiple line graph]
Year: 1975;
Cars: 4,733 BTUs/passenger mile;
Buses: 2,814 BTUs/passenger mile;
Air: 7,826 BTUs/passenger mile;
Intercity rail: 3,548 BTUs/passenger mile;
Transit rail: 2,625 BTUs/passenger mile;
Year: 1976;
Cars: 4,796 BTUs/passenger mile;
Buses: 2,896 BTUs/passenger mile;
Air: 7,511 BTUs/passenger mile;
Intercity rail: 3,278 BTUs/passenger mile;
Transit rail: 2,633 BTUs/passenger mile.
Year: 1977;
Cars: 4,710 BTUs/passenger mile;
Buses: 2,889 BTUs/passenger mile;
Air: 6,990 BTUs/passenger mile;
Intercity rail: 3,443 BTUs/passenger mile;
Transit rail: 2,364 BTUs/passenger mile.
Year: 1978;
Cars: 4,693 BTUs/passenger mile;
Buses: 2,883 BTUs/passenger mile;
Air: 6,144 BTUs/passenger mile;
Intercity rail: 3,554 BTUs/passenger mile;
Transit rail: 2,144 BTUs/passenger mile.
Year: 1979;
Cars: 4,632 BTUs/passenger mile;
Buses: 2,795 BTUs/passenger mile;
Air: 5,607 BTUs/passenger mile;
Intercity rail: 3,351 BTUs/passenger mile;
Transit rail: 2,290 BTUs/passenger mile.
Year: 1980;
Cars: 4,279 BTUs/passenger mile;
Buses: 2,813 BTUs/passenger mile;
Air: 5,561 BTUs/passenger mile;
Intercity rail: 3,065 BTUs/passenger mile;
Transit rail: 2,312 BTUs/passenger mile.
Year: 1981;
Cars: 4,184 BTUs/passenger mile;
Buses: 3,027 BTUs/passenger mile;
Air: 5,774 BTUs/passenger mile;
Intercity rail: 2,883 BTUs/passenger mile;
Transit rail: 2,592 BTUs/passenger mile.
Year: 1982;
Cars: 4,109 BTUs/passenger mile;
Buses: 3,237 BTUs/passenger mile;
Air: 5,412 BTUs/passenger mile;
Intercity rail: 3,052 BTUs/passenger mile;
Transit rail: 2,699 BTUs/passenger mile.
Year: 1983;
Cars: 4,092 BTUs/passenger mile;
Buses: 3,177 BTUs/passenger mile;
Air: 5,133 BTUs/passenger mile;
Intercity rail: 2,875 BTUs/passenger mile;
Transit rail: 2,820 BTUs/passenger mile.
Year: 1984;
Cars: 4,066 BTUs/passenger mile;
Buses: 3,307 BTUs/passenger mile;
Air: 5,298 BTUs/passenger mile;
Intercity rail: 2,923 BTUs/passenger mile;
Transit rail: 3,037 BTUs/passenger mile.
Year: 1985;
Cars: 4,110 BTUs/passenger mile;
Buses: 3,423 BTUs/passenger mile;
Air: 5,053 BTUs/passenger mile;
Intercity rail: 2,703 BTUs/passenger mile;
Transit rail: 2,809 BTUs/passenger mile.
Year: 1986;
Cars: 4,197 BTUs/passenger mile;
Buses: 3,545 BTUs/passenger mile;
Air: 5,011 BTUs/passenger mile;
Intercity rail: 2,481 BTUs/passenger mile;
Transit rail: 3,042 BTUs/passenger mile.
Year: 1987;
Cars: 4,128 BTUs/passenger mile;
Buses: 3,594 BTUs/passenger mile;
Air: 4,827 BTUs/passenger mile;
Intercity rail: 2,450 BTUs/passenger mile;
Transit rail: 3,039 BTUs/passenger mile.
Year: 1988;
Cars: 4,033 BTUs/passenger mile;
Buses: 3,706 BTUs/passenger mile;
Air: 4,861 BTUs/passenger mile;
Intercity rail: 2,379 BTUs/passenger mile;
Transit rail: 3,072 BTUs/passenger mile.
Year: 1989;
Cars: 4,046 BTUs/passenger mile;
Buses: 3,732 BTUs/passenger mile;
Air: 4,844 BTUs/passenger mile;
Intercity rail: 2,614 BTUs/passenger mile;
Transit rail: 2,909 BTUs/passenger mile.
Year: 1990;
Cars: 3,856 BTUs/passenger mile;
Buses: 3,794 BTUs/passenger mile;
Air: 4,875 BTUs/passenger mile;
Intercity rail: 2,505 BTUs/passenger mile;
Transit rail: 3,024 BTUs/passenger mile.
Year: 1991;
Cars: 3,695 BTUs/passenger mile;
Buses: 3,877 BTUs/passenger mile;
Air: 4,662 BTUs/passenger mile;
Intercity rail: 2,417 BTUs/passenger mile;
Transit rail: 3,254 BTUs/passenger mile.
Year: 1992;
Cars: 3,723 BTUs/passenger mile;
Buses: 4,310 BTUs/passenger mile;
Air: 4,516 BTUs/passenger mile;
Intercity rail: 2,534 BTUs/passenger mile;
Transit rail: 3,155 BTUs/passenger mile.
Year: 1993;
Cars: 3,804 BTUs/passenger mile;
Buses: 4,262 BTUs/passenger mile;
Air: 4,490 BTUs/passenger mile;
Intercity rail: 2,565 BTUs/passenger mile;
Transit rail: 3,373 BTUs/passenger mile.
Year: 1994;
Cars: 3,765 BTUs/passenger mile;
Buses: 4,268 BTUs/passenger mile;
Air: 4,397 BTUs/passenger mile;
Intercity rail: 2,282 BTUs/passenger mile;
Transit rail: 3,338 BTUs/passenger mile.
Year: 1995;
Cars: 3,689 BTUs/passenger mile;
Buses: 4,310 BTUs/passenger mile;
Air: 4,349 BTUs/passenger mile;
Intercity rail: 2,501 BTUs/passenger mile;
Transit rail: 3,340 BTUs/passenger mile.
Year: 1996;
Cars: 3,683 BTUs/passenger mile;
Buses: 4,340 BTUs/passenger mile;
Air: 4,172 BTUs/passenger mile;
Intercity rail: 2,690 BTUs/passenger mile;
Transit rail: 3,016 BTUs/passenger mile.
Year: 1997;
Cars: 3,646 BTUs/passenger mile;
Buses: 4,431 BTUs/passenger mile;
Air: 4,166 BTUs/passenger mile;
Intercity rail: 2,811 BTUs/passenger mile;
Transit rail: 2,854 BTUs/passenger mile.
Year: 1998;
Cars: 3,638 BTUs/passenger mile;
Buses: 4,387 BTUs/passenger mile;
Air: 4,146 BTUs/passenger mile;
Intercity rail: 2,788 BTUs/passenger mile;
Transit rail: 2,822 BTUs/passenger mile.
Year: 1999;
Cars: 3,684 BTUs/passenger mile;
Buses: 4,332 BTUs/passenger mile;
Air: 4,061 BTUs/passenger mile;
Intercity rail: 2,943 BTUs/passenger mile;
Transit rail: 2,786 BTUs/passenger mile.
Year: 2000;
Cars: 3,611 BTUs/passenger mile;
Buses: 4,515 BTUs/passenger mile;
Air: 3,952 BTUs/passenger mile;
Intercity rail: 3,253 BTUs/passenger mile;
Transit rail: 2,729 BTUs/passenger mile.
Year: 2001;
Cars: 3,583 BTUs/passenger mile;
Buses: 4,125 BTUs/passenger mile;
Air: 3,968 BTUs/passenger mile;
Intercity rail: 3,257 BTUs/passenger mile;
Transit rail: 2,737 BTUs/passenger mile.
Year: 2002;
Cars: 3,607 BTUs/passenger mile;
Buses: 4,106 BTUs/passenger mile;
Air: 3,703 BTUs/passenger mile;
Intercity rail: 3,212 BTUs/passenger mile;
Transit rail: 2,872 BTUs/passenger mile.
Year: 2003;
Cars: 3,525 BTUs/passenger mile;
Buses: 4,160 BTUs/passenger mile;
Air: 3,587 BTUs/passenger mile;
Intercity rail: 2,800 BTUs/passenger mile;
Transit rail: 2,837 BTUs/passenger mile.
Year: 2004;
Cars: 3,496 BTUs/passenger mile;
Buses: 4,323 BTUs/passenger mile;
Air: 3,339 BTUs/passenger mile;
Intercity rail: 2,760 BTUs/passenger mile;
Transit rail: 2,750 BTUs/passenger mile.
Year: 2005;
Cars: 3,571 BTUs/passenger mile;
Buses: 4,235 BTUs/passenger mile;
Air: 3,264 BTUs/passenger mile;
Intercity rail: 2,709 BTUs/passenger mile;
Transit rail: 2,784 BTUs/passenger mile.
Year: 2006;
Cars: 3,512 BTUs/passenger mile;
Buses: 4,235 BTUs/passenger mile;
Air: 3,228 BTUs/passenger mile;
Intercity rail: 2,650 BTUs/passenger mile;
Transit rail: 2,784 BTUs/passenger mile.
Source: Department of Energy.
[End of figure]
However, despite these efficiency improvements, overall fuel burn and
emissions of U.S. airlines are expected to grow in the future. FAA
forecasts that between 2008 and 2025 fuel consumption of U.S.-based
airlines will increase an average of 1.6 percent per year while revenue
passenger miles will increase an average of 3.1 percent per year over
the same period. As seen in figure 4, FAA forecasts that between 2008
and 2025 fuel consumption of U.S.-based airlines will increase an
average of 1.6 percent per year.
Figure 4: Forecasted Fuel Consumption by U.S. Airlines:
[Refer to PDF for image: line graph]
Year: 2009;
Billions of gallons consumed: 17.7.
Year: 2010;
Billions of gallons consumed: 17.9.
Year: 2011;
Billions of gallons consumed: 18.4.
Year: 2012;
Billions of gallons consumed: 19.1.
Year: 2013;
Billions of gallons consumed: 19.7.
Year: 2014;
Billions of gallons consumed: 20.2.
Year: 2015;
Billions of gallons consumed: 20.7.
Year: 2016;
Billions of gallons consumed: 21.1.
Year: 2017;
Billions of gallons consumed: 21.6.
Year: 2018;
Billions of gallons consumed: 22.1.
Year: 2019;
Billions of gallons consumed: 22.5.
Year: 2020;
Billions of gallons consumed: 23.0.
Year: 2021;
Billions of gallons consumed: 23.5.
Year: 2022;
Billions of gallons consumed: 24.0.
Year: 2023;
Billions of gallons consumed: 24.5.
Year: 2024;
Billions of gallons consumed: 25.0.
Year: 2025;
Billions of gallons consumed: 25.5.
Source: FAA Aerospace Forecast, FY 2009-2025.
[End of figure]
To develop a better understanding of the effects of human-induced
climate change and identify options for adaptation[Footnote 6] and
mitigation,[Footnote 7] two United Nations organizations established
IPCC in 1988 to assess scientific, technical, and socio-economic
information on the effects of climate change. IPCC releases and
periodically updates estimates of future greenhouse gas emissions from
human activities under different economic development scenarios. In
1999, IPCC released its report, Aviation and the Global Atmosphere,
conducted at the request of the International Civil Aviation
Organization (ICAO)--a United Nations organization that aims to promote
the establishment of international civilian aviation standards and
recommended practices and procedures. In 2007, IPCC released an update
on emissions from transportation and other sectors called the Fourth
Assessment Report of the Intergovernmental Panel on Climate Change.
These reports were developed with input from over 300 experts worldwide
and are internationally accepted and used for policy-making.
A variety of federal agencies have roles in addressing aviation
emissions. In 2004, FAA and other organizations including the National
Aeronautics and Space Administration (NASA) released a report, Aviation
and the Environment: A National Vision Statement, Framework for Goals
and Recommended Actions, through the collaborative PARTNER program,
[Footnote 8] stating a general goal to reduce overall levels of
emissions from commercial aviation and proposing actions to deal with
aviation emissions. FAA also is involved in a number of emissions-
reduction initiatives--including work on low-emissions technologies and
low-carbon alternative fuels; the implementation of a new air traffic
management system, the Next Generation Air Transportation System
(NextGen);[Footnote 9] and climate research to better understand the
impact of emissions from aviation. NASA has been involved in research
that has led to the development of technologies that reduce aircraft
emissions. Currently, NASA's Subsonic Fixed-Wing project, part of its
Fundamental Aeronautics program, aims to help develop technologies to
reduce fuel burn, noise, and emissions in the future. Both FAA and NASA
are involved in the Aviation Climate Change Research Initiative, whose
goals include improving the scientific understanding of aviation's
impact on climate change. Also, as mandated under Title II of the Clean
Air Act, the Environmental Protection Agency (EPA) promulgates certain
emissions standards for aircraft and aircraft engines[Footnote 10] and
has adopted emission standards matching those for aircraft set by ICAO.
[Footnote 11] While neither ICAO nor EPA has established standards for
aircraft engine emissions of carbon dioxide, ICAO is currently
discussing proposals for carbon dioxide emissions standards and
considering a global goal for fuel efficiency.[Footnote 12] In
addition, in 2007 a coalition of environmental interest groups filed a
petition with EPA asking the agency, pursuant to the Clean Air Act, to
make a finding that "greenhouse gas emissions from aircraft engines may
be reasonably anticipated to endanger the public health and welfare"
and, after making this endangerment finding, promulgate regulations for
greenhouse gas emissions from aircraft engines[Footnote 13].:
International concerns about the contribution of human activities to
global climate change have led to several efforts to reduce their
impact. In 1992, the United Nations Framework Convention on Climate
Change (UNFCCC)--a multilateral treaty whose objective is to stabilize
greenhouse gas concentrations in the atmosphere at a level that would
prevent dangerous human interference with the climate system--was
signed.[Footnote 14] By 1995, the parties to the UNFCCC, including the
United States, realized that progress toward this goal was not
sufficient. In December 1997, the parties reconvened in Kyoto, Japan,
to adopt binding measures to reduce greenhouse gas emissions. Under the
resulting Kyoto Protocol, which the United States has not ratified,
industrialized nations committed to reduce or limit their emissions of
carbon dioxide and other greenhouse gases during the 2008 through 2012
commitment period.[Footnote 15] The Protocol directed the
industrialized nations to work through ICAO to reduce or limit
emissions from aviation, but international aviation emissions are not
explicitly included in Kyoto's targets. In 2004, ICAO endorsed the
further development of an open emissions trading system for
international aviation, and in 2007 called for mutual agreement between
contracting states before implementation of an emissions trading
scheme. In part to meet its Kyoto Protocol requirements, the EU
implemented its ETS in 2005, which sets a cap on carbon dioxide
emissions and allows regulated entities to buy and sell emissions
allowances with one another. In 2008, the European Parliament and the
Council of the European Union passed a directive, or law, to include
aviation in the ETS. Under the directive, beginning in 2012 a cap will
be placed on total carbon dioxide emissions from all covered flights by
aircraft operators into or out of an EU airport.[Footnote 16] Many
stakeholders and countries have stated objections to the EU's plans and
legal challenges are possible. (See appendix I for a discussion of the
ETS's inclusion of aviation.) In December 2009, the parties to the
UNFCCC will convene in Copenhagen, Denmark, to discuss and negotiate a
post-Kyoto framework for addressing global climate change.
Aviation Emissions Represent a Small but Growing Share of All
Emissions:
IPCC estimates that aviation emissions currently account for about 2
percent of global human-generated carbon dioxide emissions and about 3
percent of the radiative forcing[Footnote 17] of all global human-
generated emissions (including carbon dioxide) that contribute to
climate change. On the basis of available data and assumptions about
future conditions, IPCC forecasted emissions to 2015 and forecasted
three scenarios--low, medium, and high--for growth in global aviation
carbon dioxide emissions from 2015 to 2050. These scenarios are driven
primarily by assumption about economic growth--the factor most closely
linked historically to the aviation industry's growth--but they also
reflect other aviation-related assumptions. Because IPCC's forecasts
depend in large part on assumptions, they, like all forecasts, are
inherently uncertain. Nevertheless, as previously noted, IPCC's work
reflects the input of over 300 leading and contributing authors and
experts worldwide and is internationally accepted and used for policy
making.[Footnote 18]
Aviation Contributes about 2 Percent of Global Carbon Dioxide
Emissions:
According to IPCC, global aviation contributes about 2 percent of the
global carbon dioxide emissions caused by human activities.[Footnote
19] This 2 percent estimate includes emissions from all global
aviation, including both commercial and military. Global commercial
aviation, including cargo, accounted for over 80 percent of this
estimate.[Footnote 20] In the United States, domestic aviation
contributes about 3 percent of total carbon dioxide emissions,
according to EPA data.[Footnote 21]
Many industry sectors, such as the electricity-generating and
manufacturing sectors, contribute to global carbon dioxide emissions,
as do residential and commercial buildings that use fuel and power. The
transportation sector also contributes substantially to global carbon
dioxide emissions. Specifically, it accounts for about 20 percent of
total global carbon dioxide emissions.[Footnote 22] Road transportation
accounts for the largest share of carbon dioxide emissions--74 percent-
-from the transportation sector; aviation accounts for about 13 percent
of carbon dioxide emissions from all transportation sources; and other
transportation sources, such as rail, account for the remaining 13
percent. Figure 5 shows the relative contributions of industry,
transportation, and all other sources to global carbon dioxide
emissions and breaks down transportation's share to illustrate the
relative contributions of road traffic, aviation, and other
transportation sources.
Figure 5: Global Transportation's and Global Aviation's Contributions
to Carbon Dioxide Emissions, 2004:
[Refer to PDF for image: pie-chart and subchart]
Power generation: 41%;
Industry: 18%;
Residential and services: 13%;
Other sources: 13%;
Transportation: 20%; of that number:
* Road: 74%;
* Aviation: 13%;
* Rail and other sources: 13%.
Sources: GAO presentation of International Energy Agency and IPCC data.
[End of figure]
Aviation Contributes about 3 Percent of All Human-Generated Emissions:
When other aviation emissions--such as nitrogen oxides, sulfate
aerosols, and water vapor--are combined with carbon dioxide, aviation's
estimated share of global emissions increases from 2 percent to 3
percent, according to IPCC. However, the impact of these other
emissions on climate change is less well understood than the impact of
carbon dioxide, making IPCC's combined estimate more uncertain than its
estimate for carbon dioxide alone.
Aviation emissions may contribute directly or indirectly to climate
change. Although most aviation emissions have a warming effect, sulfate
aerosols and a chemical reaction involving methane have a cooling
effect. The warming effect is termed "positive radiative forcing" and
the cooling effect "negative radiative forcing." Aviation emissions
also may contribute to the formation of cirrus clouds, which can cause
atmospheric warming, but the scientific community does not yet
understand this process well enough to quantify the warming effect of
aviation-induced cirrus clouds. Table 1 describes the direct or
indirect effects of aviation emissions on climate change.
Table 1: Types of Aviation Emissions and Their Effects at Cruising
Altitude:
Direct greenhouse gases and emissions: Carbon dioxide;
Carbon dioxide has a warming effect on the climate and remains in the
atmosphere for hundreds of years. Carbon dioxide emissions from
aviation have the same effect as those from other industry sectors
because the carbon dioxide emitted from aircraft remains in the
atmosphere long enough to be well mixed with the carbon dioxide emitted
from ground-based sources.
Direct greenhouse gases and emissions: Water vapor;
Water vapor has a warming effect on the climate and is generated from
the hydrogen contained in aviation fuel. It remains for only a short
period in the troposphere (the lowest portion of the earth's
atmosphere), where most emissions from aviation occur. The quantity of
water vapor emitted by aviation is small compared with the quantities
emitted from natural atmospheric sources.
Direct greenhouse gases and emissions: Soot particles;
Soot particles are produced during combustion and have a small warming
(positive radiative forcing[A] ) effect on the climate as they absorb
incoming sunlight and heat the atmosphere.
Indirect greenhouse gases and emissions: Ozone (from NOx);
Nitrogen emissions do not contribute to global warming directly, but
the ozone generated from increased nitrogen oxides (NOx) is a
greenhouse gas that produces a warming effect on the climate. The
effect is higher at cruising altitude than on the ground because of
longer lifetimes and greater radiative forcing in the higher levels of
the atmosphere.
Indirect greenhouse gases and emissions: Methane (NOx related);
Very little or no methane is emitted by aircraft, but NOx emissions
initiate a destruction of methane molecules, which generates an overall
cooling effect on the climate. Overall, the warming effect of NOx
emissions due to ozone formation is estimated to be higher than the
cooling that results from methane destruction.
Indirect greenhouse gases and emissions: Sulfate aerosols;
Sulfate aerosols, which arise from sulfur in jet fuel, scatter incoming
sunlight back to the atmosphere and have a relatively small cooling
effect on the climate.
Cloud formation: Contrails;
Contrails are formed through emissions of water and particles under
certain atmospheric conditions such as temperature and humidity. They
mainly consist of water already contained in the atmosphere, and
aircraft operations only trigger their formation in these areas.
Contrails cool the climate through increased reflection of solar
radiation, but also trap heat on the earth, which contributes to global
warming. Overall, contrails have a warming effect, although
uncertainties about the magnitude of this effect remain.
Cloud formation: Cirrus clouds;
Cirrus cloud formation might be augmented through aviation-induced
contrails and cloud seeding from emission particles. Cirrus clouds have
a warming effect, but exact quantifications are not yet possible.
Consequently, IPCC did not include the impact of cirrus cloud formation
in its estimates of aviation's contribution to human-generated
emissions.[B]
Source: IPCC, the Aviation Climate Change Research Initiative, and the
European Topic Center on Air and Climate Change.
[A] According to the IPCC, radiative forcing has advantages over global
warming potential (GWP) for estimating aviation's impact from short-
lived aviation emissions and aerosols and contrails. GWP is used to
measure the heat-absorbing ability of long-lived gases using carbon
dioxide as a reference. Each measure has limits and several other
impact measures including a modified GWP are under consideration to
address some of the limitations.
[B] University and government organizations, including NASA, are
conducting research on them to better understand their effects.
[End of table]
According to IPCC, when the positive radiative forcing effects of
carbon dioxide and the positive and negative radiative forcing effects
of other aviation emissions are combined, global aviation contributes
about 3 percent[Footnote 23] of human-generated positive radiative
forcing. When the radiative forcing effects of the various aviation
emissions are considered, carbon dioxide, nitrogen oxides, and
contrails have the greatest potential to contribute to climate change.
The level of scientific understanding about the impact of particular
aviation emissions on radiative forcing varies, making estimates of
their impact on climate change uncertain to varying degrees. A recent
report that described levels of scientific understanding of aviation
emissions found that the levels for carbon dioxide were high; the
levels for nitrogen oxides, water vapor, sulfates, and soot were
medium; and the levels for contrails and aviation-induced cirrus clouds
were low.[Footnote 24] Aviation's contribution to total emissions,
estimated at 3 percent, could be as low as 2 percent or as high as 8
percent, according to IPCC. Figure 6 shows IPCC's estimate of the
relative positive radiative forcing effects of each type of aviation
emission for the year 2000. The overall radiative forcing from aviation
emissions is estimated to be approximately two times that of carbon
dioxide alone.[Footnote 25]
Figure 6: Estimated Relative Contribution of Aviation Emissions to
Positive Radiative Forcing:
[Refer to PDF for image: pie-chart]
Carbon dioxide: 49%;
Nitrogen oxides: 22%;
Contrails: 20%;
Soot: 5%;
Water vapor: 4%.
Source: GAO presentation of IPCC reported study.
Note: This figure portrays the relative contributions of emissions that
have a net positive radiative forcing effect. The effect of sulfate
emissions, which have a negative radiative forcing, or cooling, effect,
is not included. The result reported for nitrogen oxides is the net
warming effect calculated by subtracting the cooling effect of methane
from the warming effect of ozone. The aviation radiative forcing impact
estimates described by IPCC in 2007 are reported as (positive) warming
and (negative) cooling in milliwatts per meter squared: carbon dioxide
(+ 25.3), ozone production from nitrogen oxides (+21.9), reduction of
atmospheric methane as a result of nitrogen oxides (-10.4), water vapor
(+2.0), sulfate particles (-3.5), soot particles (+2.5), and contrails
(+10.0). For cirrus clouds, IPCC had no best estimate due to
uncertainty, but a possible range of +10 to +80 was reported. The
relative contributions of emissions in this chart are an approximation
because of the uncertainty surrounding the non-carbon dioxide forcing
estimates.
[End of figure]
IPCC, 2007: Climate Change 2007: The Physical Science Basis.
Contribution of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M.
Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and New
York, NY, USA.
Global Aviation Emissions Are Expected to Grow but Forecasts Vary,
Primarily Reflecting Different Economic Growth Assumptions:
IPCC generated three scenarios that forecasted the growth of global
aviation carbon dioxide emissions from the near-term (2015) to the long-
term (2050) and described these scenarios in its 1999 report. These
forecasts are generated by models that incorporate assumptions about
future conditions, the most important of which are assumptions about
global economic growth and related increases in air traffic. Other
assumptions include improvements in aircraft fuel efficiency and air
traffic management and increases in airport and runway capacity.
Because the forecasts are based on assumptions, they are inherently
uncertain.
Forecasts of Global Economic Growth and Air Traffic Primarily Drive
IPCC's Emissions Estimates:
Historically, global economic growth has served as a reliable indicator
of air traffic levels. Aviation traffic has increased during periods of
economic growth and slowed or decreased during economic slowdowns. As
figure 7 shows, U.S and global passenger traffic (including the U.S.)
generally trended upward from 1978 through 2008, but leveled off or
declined during economic recessions in the United States.
Figure 7: Changes in Global and U.S. Aviation Passenger Traffic, 1978
through 2008:
[Refer to PDF for image: multiple line graph]
PRK: revenue passenger kilometers;
PRM: revenue passenger miles.
Year: 1978;
Global passenger traffic: 0.93 trillion RPK;
U.S. Carrier passenger traffic: 236.2 billion PRM.
Year: 1979;
Global passenger traffic: 1.06 trillion RPK;
U.S. Carrier passenger traffic: 267.3 billion PRM.
Year: 1980 (period of recession);
Global passenger traffic: 1.09 trillion RPK;
U.S. Carrier passenger traffic: 257.4 billion PRM.
Year: 1981 (period of recession);
Global passenger traffic: 1.12 trillion RPK;
U.S. Carrier passenger traffic: 246.3 billion PRM.
Year: 1982;
Global passenger traffic: 1.14 trillion RPK;
U.S. Carrier passenger traffic: 258.9 billion PRM.
Year: 1983;
Global passenger traffic: 1.19 trillion RPK;
U.S. Carrier passenger traffic: 292 billion PRM.
Year: 1984;
Global passenger traffic: 1.28 trillion RPK;
U.S. Carrier passenger traffic: 315.3 billion PRM.
Year: 1985;
Global passenger traffic: 1.37 trillion RPK;
U.S. Carrier passenger traffic: 348 billion PRM.
Year: 1986;
Global passenger traffic: 1.45 trillion RPK;
U.S. Carrier passenger traffic: 375.7 billion PRM.
Year: 1987;
Global passenger traffic: 1.59 trillion RPK;
U.S. Carrier passenger traffic: 430.7 billion PRM.
Year: 1988;
Global passenger traffic: 1.71 trillion RPK;
U.S. Carrier passenger traffic: 436.5 billion PRM.
Year: 1989;
Global passenger traffic: 1.77 trillion RPK;
U.S. Carrier passenger traffic: 446.1 billion PRM.
Year: 1990 (period of recession);
Global passenger traffic: 1.89 trillion RPK;
U.S. Carrier passenger traffic: 472.4 billion PRM.
Year: 1991 (period of recession);
Global passenger traffic: 1.85 trillion RPK;
U.S. Carrier passenger traffic: 461 billion PRM.
Year: 1992;
Global passenger traffic: 1.93 trillion RPK;
U.S. Carrier passenger traffic: 492.6 billion PRM.
Year: 1993;
Global passenger traffic: 1.95 trillion RPK;
U.S. Carrier passenger traffic: 502.7 billion PRM.
Year: 1994;
Global passenger traffic: 2.10 trillion RPK;
U.S. Carrier passenger traffic: 535.1 billion PRM.
Year: 1995;
Global passenger traffic: 2.24 trillion RPK;
U.S. Carrier passenger traffic: 556.4 billion PRM.
Year: 1996;
Global passenger traffic: 2.43 trillion RPK;
U.S. Carrier passenger traffic: 594.1 billion PRM.
Year: 1997;
Global passenger traffic: 2.57 trillion RPK;
U.S. Carrier passenger traffic: 616.5 billion PRM.
Year: 1998;
Global passenger traffic: 2.63 trillion RPK;
U.S. Carrier passenger traffic: 633.8 billion PRM.
Year: 1999;
Global passenger traffic: 2.80 trillion RPK;
U.S. Carrier passenger traffic: 669 billion PRM.
Year: 2000;
Global passenger traffic: 3.04 trillion RPK;
U.S. Carrier passenger traffic: 710.7 billion PRM.
Year: 2001 (period of recession);
Global passenger traffic: 2.95 trillion RPK;
U.S. Carrier passenger traffic: 679.2 billion PRM.
Year: 2002;
Global passenger traffic: 2.96 trillion RPK;
U.S. Carrier passenger traffic: 658.7 billion PRM.
Year: 2003;
Global passenger traffic: 3.02 trillion RPK;
U.S. Carrier passenger traffic: 682.9 billion PRM.
Year: 2004;
Global passenger traffic: 3.45 trillion RPK;
U.S. Carrier passenger traffic: 765.4 billion PRM.
Year: 2005;
Global passenger traffic: 3.72 trillion RPK;
U.S. Carrier passenger traffic: 812.2 billion PRM.
Year: 2006;
Global passenger traffic: 3.94 trillion RPK;
U.S. Carrier passenger traffic: 827.2 billion PRM.
Year: 2007 (period of recession);
Global passenger traffic: 4.20 trillion RPK;
U.S. Carrier passenger traffic: 855.6 billion PRM.
Year: 2008 (period of recession);
Global passenger traffic: 4.28 trillion RPK;
U.S. Carrier passenger traffic: 837 billion PRM.
Sources: U.S. Department of Transportation data and ICAO data from the
Air Transport Association.
[End of figure]
Forecast models described in IPCC's report incorporate historical
trends and the relationship between economic growth and air traffic to
produce scenarios of global aviation's potential future carbon dioxide
emissions. IPCC used a NASA emissions forecast for carbon dioxide
emissions until 2015. IPCC used an ICAO emissions forecasting model to
forecast emissions from 2015 to 2050 using three different assumptions
for global economic growth--low (2.0 percent), medium (2.9 percent),
and high (3.5 percent). As a result, IPCC produced three different
potential scenarios for future air traffic and emissions.[Footnote 26]
The 2050 scenarios include a 40 percent to 50 percent increase in fuel
efficiency by 2050 from improvements in aircraft engines and airframe
technology and from deployment of an advanced air traffic management
system (these are discussed in more detail below). Figure 8 shows
IPCC's low-, mid-, and high-range scenarios for carbon dioxide
emissions for 2015, 2025, and 2050 as a ratio over 1990 emissions. IPCC
used the medium economic growth rate scenario to estimate aviation's
contribution to overall emissions in 2050.
Figure 8: IPCC's Scenarios for Global Aviation Carbon Dioxide Emissions
(Ratio of etimate ovr 1990 level):
[Refer to PDF for image: multiple line graph]
Year: 1990;
High GDP scenario: 1;
Medium GDP scenario: 1;
Low GDP scenario: 1.
Year: 2000;
High GDP scenario: 1.3;
Medium GDP scenario: 1.3;
Low GDP scenario: 1.3.
Year: 2015;
High GDP scenario: 1.9;
Medium GDP scenario: 1.9;
Low GDP scenario: 1.9.
Year: 2025;
High GDP scenario: 2.6;
Medium GDP scenario: 2.1;
Low GDP scenario: 1.8.
Year: 2050;
High GDP scenario: 4.4;
Medium GDP scenario: 2.8;
Low GDP scenario: 1.6.
Source: IPCC.
Note: Includes advanced air traffic management and 40 percent to 50
percent fuel efficiency gain by 2050.
[End of figure]
IPCC compared aviation and overall emissions for the future and found
that global aviation carbon dioxide emissions could increase at a
greater rate than carbon dioxide emissions from all other sources of
fossil fuel combustion. For example, for the medium GDP growth rate
scenario, IPCC assumed a 2.9 percent annual average increase in global
GDP, which translated into almost a tripling (a 2.8 times increase) of
aviation's global carbon dioxide emissions from 1990 to 2050. For the
same medium GDP growth scenario, IPCC also estimated a 2.2 times
increase of carbon dioxide emissions from all other sources of fossil
fuel consumption worldwide during this period. Over all, using the
midrange scenario for global carbon dioxide emissions and projections
for emissions from other sources, IPCC estimated that in 2050, carbon
dioxide emissions from aviation could be about 3 percent of global
carbon dioxide emissions, up from 2 percent. IPCC further estimated
that, when other aviation emissions were combined with carbon dioxide
emissions, aviation would account for about 5 percent of global human-
generated positive radiative forcing, up from 3 percent.[Footnote 27]
IPCC concluded that the aviation traffic estimates for the low-range
scenario, though plausible, were less likely given aviation traffic
trends at the time the report was published in 1999. IPCC's 2007 Fourth
Assessment Report included two additional forecasts of global aviation
carbon dioxide emissions for 2050 developed through other studies.
[Footnote 28] Both of these studies forecasted mid-and high-range
aviation carbon dioxide emissions for 2050 that were within roughly the
same range as the 1999 IPCC report's forecasts.[Footnote 29] For
example, one study using average GDP growth assumptions that were
similar to IPCC's showed mid-and high-range estimates that were close
to IPCC's estimates.
In 2005, FAA forecasted a 60 percent growth in aviation carbon dioxide
and nitrogen oxide emissions from 2001 to 2025. However, FAA officials
recently noted that this estimate did not take into account anticipated
aircraft fleet replacements, advances in aircraft and engine
technology, and improvements to the air transportation system, nor did
it reflect the recent declines in air traffic due to the current
recession. After taking these factors into account, FAA reduced its
estimate in half and now estimates about a 30 percent increase in U.S.
aviation emissions from 2001 to 2025.[Footnote 30] To account for some
uncertainties in FAA's emissions forecasting, FAA officials said they
are working on creating future scenarios for the U.S. aviation sector
to assess the influence of a range of technology and market assumptions
on future emissions levels.
Other Forecasts Show Continued Long-term Growth, but Emissions Could
Fall below Estimated Levels during the Current Economic Downturn:
While recent aviation forecasts are generally consistent with IPCC's
expectation for long-term global economic growth, the current economic
slowdown has led to downward revisions in growth forecasts. For
example, in 2008, Boeing's annual forecast for the aviation market
projected a 3.2 percent annual global GDP growth rate from 2007 to
2027. However, this estimate was made before the onset of negative
global economic growth in 2009 and could be revised downward in
Boeing's 2009 forecast. According to FAA's March 2009 Aerospace
Forecast, global GDP, which averaged 3 percent annual growth from 2000
to 2008, will be 0.8 percent from 2008 to 2010 before recovering to an
estimated average annual growth rate of 3.4 percent from 2010 to 2020.
[Footnote 31] The International Air Transport Association has predicted
that global air traffic will decrease by 3 percent in 2009 with the
economic downturn. Moreover, according to the association, even if air
traffic growth resumes in 2010, passenger air traffic levels will be 12
percent lower in the first few years after the slowdown and 9 percent
lower in 2016 than the association forecasted in late 2007. To the
extent that air traffic declines, emissions also will decline.
Assumptions about Other Factors Could Affect IPCC's Forecasts:
In developing its forecasts, IPCC made assumptions about factors other
than economic growth that also affected its forecast results, as IPCC
itself, experts we interviewed, and FAA have noted:
* IPCC assumed that advances in aircraft technology and the
introduction of new aircraft would increase fuel efficiency by 40
percent to 50 percent from 1997 through 2050.[Footnote 32]
* IPCC assumed that an ideal air traffic management system would be in
place worldwide by 2050,[Footnote 33] reducing congestion and delays.
* IPCC assumed that airport and runway capacity would be sufficient to
accommodate future air traffic levels.
However, if IPCC's assumptions about improvements in fuel efficiency
and air traffic management are not realized, aircraft could produce
higher emissions levels than IPCC estimated and IPCC's estimates would
be understated. Conversely, if airports and runways have less capacity
than IPCC assumed, then air traffic levels could be lower and,
according to IPCC and some experts, IPCC's forecast could overstate
future aviation emissions. Finally, IPCC pointed out that its estimate
that aviation will contribute 5 percent of positive radiative forcing
in 2050 does not include the potential impact of aviation-induced
cirrus clouds, which could be substantial.[Footnote 34]
Because IPCC's forecasts are based on assumptions about future
conditions and scientific understanding of the radiative forcing
effects of certain aviation emissions is limited, IPCC's forecasts are
themselves uncertain. According to FAA officials, given the numerous
assumptions and inherent uncertainties involved in forecasting aviation
emissions levels out to the year 2050, along with the significant
shocks and structural changes the aviation community has experienced
over the last few years, IPCC's projections are highly uncertain, even
for the midrange scenario. If emissions from aviation and all other
sectors continue to grow at about the same relative rate, aviation's
contribution as a portion of overall emissions will not change
significantly. However, if significant reductions are made in overall
emissions from other sources and aviation emission levels continue to
grow, aviation's contribution could grow.
Experts Believe Future Technological and Operational Improvements Are
Likely to Help Reduce Emissions from Commercial Aircraft, but Likely
Not by Enough to Fully Offset Estimated Market Growth:
According to experts we interviewed, a number of different
technological and operational improvements related to engines, aircraft
design, operations, next-generation air traffic management, and fuel
sources are either available now or are anticipated in the future to
help reduce carbon dioxide emissions from aircraft. We interviewed and
surveyed 18 experts in the fields of aviation and climate change and
asked them to assess a number of improvements to reduce emissions using
a variety of factors, such as potential costs and benefits, and then
used the results to inform the following discussion. (Complete survey
results can be found in appendix III.) The development and adoption of
low-emissions technologies is likely to be dependent upon fuel prices
or any government policies that price aircraft emissions. Higher fuel
prices or prices on emissions--for example through government policies
such as an emissions tax--would make the costs of low-emissions
technologies relatively cheaper and are likely to encourage their
development. In addition, while fuel efficiency and emissions
reductions may be important to airlines, so are a number of other
factors, including safety, performance, local air quality, and noise
levels, and trade-offs may exist between these factors.
Experts Believe That Although Many Technologies Are Expected to Help
Reduce Emissions Growth in the Future, They Involve Trade-offs:
Aircraft Engine Improvements:
Improvements to aircraft engines have played a primary role in
increasing fuel efficiency and reducing engine emission rates; experts
we interviewed expect them to do so in the future--one study estimates
that 57 percent of improvements in aircraft energy intensity between
1959 and 1995 were due to improvements in engine efficiency.[Footnote
35] Such improvements have resulted from increasing engine pressure and
temperatures (which increases their efficiency and decreases fuel
usage) and improving the "bypass ratio," a measure of airflow through
the engine.[Footnote 36] However, according to experts we surveyed,
further advances in these technologies may face high development costs
(see table 2), and some may not be available for commercial use any
time soon because engineers still face challenges in improving engine
technology.
Table 2: Selected Potential Aircraft Engine Improvements to Reduce
Emissions:
Improvement: Geared turbofan engine--more fuel efficient engine;
Potential reduction in carbon dioxide emissions[A]: Medium;
Potential research and development costs[A]: Medium;
Estimated time frame for commercial use[B]: Short-medium;
Potential for public acceptance[A]: High.
Improvement: Open rotor engine--engine fan blades not enclosed;
Potential reduction in carbon dioxide emissions[A]: High;
Potential research and development costs[A]: High;
Estimated time frame for commercial use[B]: Medium;
Potential for public acceptance[A]: Low-medium.
Improvement: Distributed propulsion systems--many small engines instead
of few large ones;
Potential reduction in carbon dioxide emissions[A]: Medium;
Potential research and development costs[A]: High;
Estimated time frame for commercial use[B]: Long;
Potential for public acceptance[A]: High.
Source: GAO survey of experts.
Note: Between 8 and 13 experts responded to each of our questions about
technological improvements.
[A] We did not provide definitions for "low," "medium," or "high" in
these cases.
[B] Short timeframe (15 years).
[End of table]
Some technologies may be available sooner than others, but all present
a range of challenges and tradeoffs:
* One latest-generation aircraft engine, the geared turbofan engine, is
likely to be available for use in certain aircraft in the next few
years; promises to reduce emissions according to its manufacturer,
Pratt & Whitney; and may face few challenges to widespread adoption.
[Footnote 37] According to Pratt & Whitney, this engine design is
estimated to reduce fuel burn and emissions by 12 percent, compared
with similar engines now widely used, in part due to an increase in the
engine's bypass ratio. The geared turbofan engine is the result of
research conducted by NASA and Pratt & Whitney.[Footnote 38]
* Another engine technology, which could be introduced in the next 5 to
15 years, is the "open rotor" engine. It may deliver even greater
emissions reductions but may face consumer-related challenges. The open
rotor engine holds the engine fan blades on the outside of the engine
case, thereby increasing the air flow around the engine, the effective
bypass ratio, and the efficiency of the engine's propulsion. However,
this engine may be noisy and its large, visible engine blades could
raise consumer concerns according to experts we surveyed. Research in
the United States is currently a joint effort of NASA and General
Electric. Rolls-Royce is also pursuing this technology.
* In the longer term, despite some engineering challenges, distributed
propulsion technologies also hold promise for reducing aircraft
emissions. Distributed propulsion systems would place many small
engines throughout an aircraft instead of using a few large engines, as
today's aircraft do. Experts we interviewed said that engineering
challenges must be overcome with distributive propulsion, including
determining the best and most efficient way to distribute power and
store fuel. NASA is currently involved in distributed propulsion
research.
Aircraft Improvements:
Aircraft improvements also have played a role in reducing emissions
rates in the past and experts we interviewed expected them to continue
to do so. Through improvements in materials used to build aircraft and
other improvements that increase aerodynamics and reduce drag, aircraft
have become more fuel efficient over time. In the short term,
improvements in aircraft materials, leading to decreased weight, and
improvements in aerodynamics will help reduce fuel consumption and,
thus, emissions rates. In the longer term, new aircraft designs,
primarily a blended wing-body aircraft, hold potential for greater
reductions in emissions rates. However, new aircraft concepts face
engineering and consumer acceptance challenges and new technologies are
likely to incur high development costs (see table 3).
Table 3: Selected Aircraft Improvements to Reduce Emissions:
Improvement: Blended wing-body--Fuselage and wings as part of one
airframe;
Potential reduction in carbon dioxide emissions[A]: High;
Potential research and development costs[A]: High;
Estimated time frame for commercial use[B]: Long;
Potential for public acceptance[A]: Low-medium.
Improvement: Lightweight composite airframes--Lightweight materials;
Potential reduction in carbon dioxide emissions[A]: Medium;
Potential research and development costs[A]: Medium;
Estimated time frame for commercial use[B]: Medium;
Potential for public acceptance[A]: High.
Improvement: Winglets--Wing attachments to reduce drag;
Potential reduction in carbon dioxide emissions[A]: Low;
Potential research and development costs[A]: Low;
Estimated time frame for commercial use[B]: Short[C];
Potential for public acceptance[A]: High.
Source: GAO survey of experts.
Note: Between 11 and 14 experts responded to each of our questions
about technological improvements.
[A] We did not provide definitions for "low," "medium," or "high" in
these cases.
[B] Short timeframe (15 years).
[C] Winglets are already available and used by a number of airlines.
[End of table]
The following improvements to aircraft should help reduce aircraft fuel
consumption and emissions in the long term, despite costs and
challenges:
* The use of lightweight composite materials in aircraft construction
has led to weight and fuel burn reductions in the past and is expected
to continue to do so in the future. Over time, aircraft manufacturers
have increasingly replaced more traditional materials such as aluminum
with lighter-weight composite materials in airframe construction. For
example, according to Boeing, 50 percent of the weight of the airframe
of the Boeing 787, expected to be released in 2010, will be
attributable to composite materials, compared with 12 percent
composites in a currently available Boeing 777. According to Airbus, it
first began using composite materials in airframe construction in 1985,
and about 25 percent of the airframe weight of an A380 manufactured in
2008 was attributable to composites. By reducing the weight of the
airframe, the use of composites reduces aircraft weight, fuel burn, and
emissions rates.
* Retrofits such as winglets--wing extensions that reduce drag--can be
made to aircraft to make them more aerodynamic but may have limited
potential for future emissions reductions according to experts we
surveyed. By improving airflow around wings, winglets reduce drag and
improve fuel efficiency, thus reducing emissions by a modest amount.
Boeing estimates that the use of winglets on a 737 reduces fuel burn by
3.5 percent to 4 percent on trips of over 1,000 nautical miles. Many
new aircraft can be purchased with winglets, and existing aircraft also
can be retrofitted with them. However winglets have already become very
common on U.S. commercial airline aircraft and provide limited benefit
for short-haul flights. According to experts we surveyed, there is low
potential for future fuel consumption and emissions reductions from
winglets.
* Redesigned aircraft, such as a blended wing-body aircraft--that is,
an aircraft in which the body and wings are part of one airframe--hold
greater potential for reducing emissions, according to experts we
surveyed, though these face challenges as well. Several public and
private organizations, including NASA and Boeing are conducting
research on such aircraft. Many experts expect that blended wing-body
aircraft will reduce emissions through improved aerodynamics and
lighter weight. Estimates for potential emissions reductions include 33
percent compared with currently available aircraft according to NASA.
However, these new designs face challenges; notably, according to
experts we interviewed, development costs are likely to be substantial,
their radically different appearance may pose consumer acceptance
issues, and they may require investments in modifying airports.
[Footnote 39]
Experts Also Expect Operational Improvements to Help Reduce Aircraft
Emissions in the Future, but Reductions May Be Limited:
Airlines have already taken a number of steps to improve fuel
efficiency over time; however, the potential for future improvements
from these measures may be limited. Airlines have increased their load
factors (the percentage of seats occupied on flights), increasing the
fuel efficiency of aircraft on a per-passenger basis. Load factors were
about 80 percent for U.S. carriers in 2008, compared with about 65
percent in 1995. However, some experts we interviewed said the
potential for additional future emissions reductions from increasing
load factors may be small because they are already so high. Airlines
also have removed many unnecessary items from aircraft and minimized
supplies of certain necessary items, such as water, carried on board.
As a result, according to some experts we interviewed, there may be
little additional improvement in reducing emissions by reducing on-
board weight. Airlines also have made other voluntary operational
changes to reduce emissions, such as reducing speeds on certain routes,
which reduces fuel use, and washing aircraft engines to make them
cleaner and more efficient. Airlines also have retired less-fuel-
efficient aircraft and replaced them with more-fuel-efficient models.
For example, in 2008, American Airlines announced it was replacing more
of its fuel-inefficient MD-80 aircraft with more efficient Boeing 737-
800 aircraft. In addition, Continental Airlines, in 2008, replaced
regional jets with turboprop planes on many routes. Still other
improvements also are available for airlines to reduce emissions in the
future, but the experts we interviewed ranked the potential for
emissions reductions and consumer acceptance of these improvements as
low (see table 4).
Table 4: Selected Operational Improvements to Reduce Emissions:
Improvement: Air-to-air refueling--Air tankers fueling aircraft in
flight;
Potential reduction in carbon dioxide emissions[A]: Low;
Potential research and development costs[A]: High;
Estimated time frame for commercial use[B]: Long;
Potential for public acceptance[A]: Low.
Improvement: Engine washing--To improve engine performance;
Potential reduction in carbon dioxide emissions[A]: Low;
Potential research and development costs[A]: Low;
Estimated time frame for commercial use[B]: Short;
Potential for public acceptance[A]: High.
Improvement: Formation flying--Multiple aircraft flying close together
to reduce drag;
Potential reduction in carbon dioxide emissions[A]: Low;
Potential research and development costs[A]: Medium-high;
Estimated time frame for commercial use[B]: Medium-long;
Potential for public acceptance[A]: Low.
Improvement: Multi-stage long distance flights--Use of fueling stops on
long-distance flights;
Potential reduction in carbon dioxide emissions[A]: Low-medium;
Potential research and development costs[A]: Low;
Estimated time frame for commercial use[B]: Short;
Potential for public acceptance[A]: Low.
Source: GAO survey of experts.
Note: Between 9 and 12 survey respondents answered each of our
questions about operational improvements to reduce emissions.
[A] We did not provide definitions for "low," "medium," or "high" in
these cases.
[B] Short timeframe (15 years).
[End of table]
Airlines could make other operational changes to reduce fuel burn and
emissions but are unlikely to do so, because the potential for consumer
acceptance of such changes is low according to experts we surveyed. For
example, aircraft could fly in formation to improve airflow and reduce
fuel burn. More specifically, rather than flying individually, several
aircraft could fly in proximity to one another, reducing drag of
aircraft and subsequently fuel use. However, aircraft would fly closer
to one another than FAA's regulations currently allow and additional
technological and aerodynamics research needs to be done. Another
potential option, currently used for military purposes, is air-to-air
refueling. Under this option, aircraft would be fueled in flight by
tanker aircraft, reducing the amount and weight of fuel needed for the
flight. However, DOT staff told us that air-to-air refueling may pose
safety risks similar to those posed by formation flying. Some experts
also have suggested that airlines make in-route on-ground fueling stops
on long-haul flights, so they could reduce the amount of fuel they
carry. However, more fueling stops could have negative effects on air
quality at airports used for these stops as well as on air traffic
operations.
Air Traffic Management Improvements through NextGen Will Incorporate
Technological and Operational Improvements to Help Reduce Aircraft
Emissions According to Experts:
According to FAA, some of the air traffic management improvements that
are part of NextGen--the planned air traffic management system designed
to address the impacts of future traffic growth--can help reduce
aircraft fuel consumption and emissions in the United States. Besides
improving air traffic management, NextGen has environmental goals,
which include accelerating the development of technologies that will
lower emissions and noise. According to FAA, it is conducting a review
to develop a set of NextGen goals, targets and metrics for climate
change, as well as for noise and local air quality emissions. NextGen
has the potential to reduce aircraft fuel burn by 2025, according to
FAA, in part through technologies and procedures that reduce congestion
and create more direct routing. Some procedures and technologies of
NextGen have already been implemented and have already led to emissions
reductions. Similarly, in Europe through the Single European Sky Air
Traffic Management Research Program (SESAR), air traffic management
technologies and procedures will be upgraded and individual national
airspace systems will be merged into one, helping to reduce emissions
per flight by 10 percent according to EUROCONTROL, the European
Organization for the Safety of Air Navigation. However, some experts we
met with said that because some of SESAR's technologies and procedures
have already been implemented, future fuel savings might be lower.
Table 5 provides information on selected components of NextGen that
hold potential for reducing aircraft emissions.
Table 5: Selected Air Traffic Management Improvements to Reduce
Emissions:
Improvement: Required navigation performance--More precise routes;
Potential reduction in carbon dioxide emissions[A]: Medium;
Potential research and development costs[A]: Medium;
Estimated time frame for commercial use[B]: Medium;
Potential for public acceptance[A]: High.
Improvement: Automatic Dependent Surveillance-Broadcast--Satellite
navigation system;
Potential reduction in carbon dioxide emissions[A]: Medium;
Potential research and development costs[A]: Medium;
Estimated time frame for commercial use[B]: Short;
Potential for public acceptance[A]: High.
Improvement: Continuous Descent Arrival--More fuel efficient landings;
Potential reduction in carbon dioxide emissions[A]: Low-Medium;
Potential research and development costs[A]: Medium;
Estimated time frame for commercial use[B]: Short;
Potential for public acceptance[A]: High.
Improvement: NextGen Network-Enabled Weather--Advanced real-time
weather data;
Potential reduction in carbon dioxide emissions[A]: Medium;
Potential research and development costs[A]: Medium;
Estimated time frame for commercial use[B]: Medium;
Potential for public acceptance[A]: High.
Source: GAO survey of experts,
Note: 7 to 13 experts answered each of our survey questions about
NextGen improvements:
[A] We did not provide definitions for "low," "medium," or "high" in
these cases.
[B] Short timeframe (15 years).
[End of table]
NextGen has the potential to reduce fuel consumption and emissions
through technologies and operational procedures:
* NextGen makes use of air traffic technologies to reduce emissions.
For example, the Automatic Dependent Surveillance-Broadcast (ADS-B)
satellite navigation system is designed to enable more precise control
of aircraft during flight, approach, and descent, allowing for more
direct routing and thus reducing fuel consumption and emissions. Also,
Area Navigation (RNAV) will compute an aircraft's position and ground
speed and provide meaningful information on the flight route to pilots,
enabling them to save fuel through improved navigational capability.
NextGen Network-Enabled Weather will provide real-time weather data
across the national airspace system, helping reduce weather-related
delays and allowing aircraft to best use weather conditions to improve
efficiency.
* NextGen also relies on operational changes that have demonstrated the
potential to reduce fuel consumption and emissions rates. Continuous
Descent Arrivals (CDA) allow aircraft to remain at cruise altitudes
longer as they approach destination airports, use lower power levels,
and therefore produce lower emissions during landings. CDAs are already
in place in a number of U.S. airports and according to FAA, the use of
CDAs at Atlanta Hartsfield International Airport reduces carbon dioxide
emissions by an average of about 1,300 pounds per flight. Required
Navigation Performance (RNP) also permits an aircraft to descend on a
more precise route, reducing its consumption of fuel and lowering its
carbon dioxide emissions. According to FAA, over 500 RNAV and RNP
procedures and routes have been implemented. Funding and other
challenges, however, affect FAA's implementation of these various
NextGen procedures and technologies.[Footnote 40]
Alternative Fuel Sources Have Potential for Reducing Aircraft
Greenhouse Gas Emissions, but Challenges Exist:
The use of alternative fuels, including those derived from biological
sources (biofuels), has the potential to reduce greenhouse gas
emissions from aircraft in the future; however, these fuels also
present a number of challenges and environmental concerns. While the
production and use of biofuels result in greenhouse gas emissions, the
extent to which they provide a reduction in greenhouse gas emissions
depends on whether their emissions on an energy-content basis are less
than those resulting from the production and use of fossil fuels.
[Footnote 41] To date, some assessments of biofuels have shown a
potential reduction in greenhouse gas emissions when compared with
fossil fuels, such as jet fuel. However, researchers have not agreed on
the best approach for determining the greenhouse gas effects of
biofuels and the magnitude of any greenhouse gas reductions
attributable to their production and use.[Footnote 42] FAA, EPA, and
U.S. Air Force officials we met with said that quantifying the life-
cycle emission of biofuels is difficult, but work in this area is
currently under way.[Footnote 43] For example, according to EPA, the
agency has developed a comprehensive methodology to determine the life-
cycle emissions, including both direct and indirect emissions, of a
range of biofuels. This methodology, which involved extensive
coordination with experts outside of and across the federal government,
was included in the recent notice of proposed rulemaking on the
renewable fuel standard. Non-oil-energy sources, such as hydrogen, have
potential for providing energy for ground transport, but many experts
we met with said that such sources are unlikely to have use for
commercial aircraft given technological, cost, and potential safety
issues.[Footnote 44]
According to experts we interviewed, a variety of sources could be used
to produce biofuels for aircraft, including biomasses such as
switchgrass and forest and municipal waste; and oils from jatropha (a
drought-resistant plant that can grow in marginal soil), algae,
camelina (a member of the mustard family that can grow in semiarid
regions), palm, and soy. However, many experts claim that some of these
crops are unsuitable for use as biofuels because they may have negative
environmental and economic consequences, such as potentially reducing
the supply and quality of water, reducing air quality and biodiversity,
and limiting global food supplies. For example, cultivating palm for
biofuel production might lead to deforestation, thereby increasing both
greenhouse gas emissions and habitat loss. In addition, jatropha has
been identified as an invasive species in some regions and, because of
its aggressive growth, may have the potential to reduce available
habitat for native species. According to experts we met with, algae, on
the other hand, are seen as a potentially viable source: they can be
grown using saltwater and in a variety of other environments. In
addition, according to DOT, camelina appears to be a potential biofuel
source in the short term as it is not currently used for food and uses
limited water for development.
However, many experts we interviewed raised questions about the
availability of future supplies of biofuels. According to the experts,
large investments in fuel production facilities will likely be needed
because little industrial capacity and compatible infrastructure
currently exist to create biofuels.[Footnote 45] The cost of current
algae conversion technology has, for example raised obstacles to the
commercial-scale production needed to obtain significant supplies in
the future. Given that future alternative fuels will have many uses,
airlines will compete with other sources, including road
transportation, for those limited supplies. Compared with the market
for ground transport, the market for fuels for commercial aviation is
small, leading some experts to believe that fuel companies are more
likely to focus their biofuel efforts on the ground transport market
than on the commercial aviation market. Some experts we met with said
that given the relatively small size of the market, limited biofuel
supplies should be devoted to road transportation since road
transportation is the largest contributor of emissions from the
transportation sector.[Footnote 46]
A large number of industry and government participants, including
airlines, fuel producers, and manufacturers, are currently conducting
research and development on alternative fuels for aircraft. One effort
is the Commercial Aviation Alternative Fuels Initiative, whose members
include FAA, airlines, airports, and manufacturers. The goal of this
initiative is to "promote the development of alternative fuels that
offer equivalent levels of safety and compare favorably with petroleum-
based jet fuel on cost and environmental bases, with the specific goal
of enhancing security of energy supply." Any developed biofuel will be
subject to the same certification as petroleum-based jet fuel to help
ensure its safety. In addition, other government efforts are under way,
most notably the Biomass Research and Development Initiative. This
initiative is a multiagency effort to coordinate and accelerate all
federal biobased products and bioenergy research and development. The
Department of Transportation is one of the initiative's participants.
Finally, the aviation industry has conducted a number of test flights
using a mixture of biofuels and jet fuel. These test flights have
demonstrated that fuel blends containing biofuels have potential for
use in commercial aircraft. In February 2008, Virgin Atlantic Airlines
conducted a demonstration flight of a Boeing 747 fueled by a blend of
jet fuel (80 percent) and coconut-and babassu-oil-based fuels (20
percent). In December 2008, Air New Zealand conducted a test flight of
a Boeing 747 fueled by a blend consisting of an equal mixture of jet
fuel and jatropha oil. In January 2009, Continental Airlines conducted
a test flight using a fuel blend of 50 percent jet fuel, and a jatropha
and algae biofuel blend on a Boeing 737.[Footnote 47] In January 2009,
Japan Airlines conducted a test flight of a Boeing 747 fueled by a
blend including camelina oil. According to the airlines, the results of
all these tests indicate that there was no change in performance when
engines were fueled using the biofuel blends. For example, the pilot of
the Air New Zealand test flight noted that both on-ground and in-flight
tests indicated that the aircraft engines performed well while using
the biofuel.
Improvements to Reduce Emissions from Aircraft Face Challenges and
According to Experts Adopting Them May Not Be Enough to Offset Future
Market and Emissions Growth:
Future fuel prices are likely to be a major factor in influencing the
development of low-emissions technologies for commercial aviation.
According to the airline industry, fuel costs provide an incentive for
airlines to reduce fuel consumption and emissions. However, according
to some experts we interviewed, short-term increases in fuel prices may
not provide enough of an incentive for the industry to adopt certain
low-emission improvements. For example, the commercial airlines would
have greater incentive to adopt fuel saving technologies if the
projected fuel savings are greater than the improvement's additional
life-cycle cost. The higher existing and projected fuel prices are, the
more likely airlines would undertake such improvements, all else the
same. One expert said that if fuel costs were expected to consistently
exceed $140 per barrel in the future, much more effort would be made to
develop a finished open rotor engine quickly. The price of fuel as a
factor in providing an incentive for the development and adoption of
low-emission technologies is seen in some historical examples in NASA
research. While winglets were first developed through a NASA research
program in the 1970s, they were not used commercially until a few years
ago when higher fuel prices justified their price. Additionally,
although NASA currently is sponsoring research into open rotor engines,
the agency also did so in the 1980s in response to high fuel prices.
That research was discontinued before the technology could be matured,
however, when fuel prices dropped dramatically in the late 1980s.
In addition, the current economic recession has impacted commercial
airlines and may cause some airlines to cut back on purchases of newer
and more fuel-efficient aircraft. For example, the U.S. airline
industry lost about $3.7 billion in 2008, and while analysts are
uncertain about its profitability 2009, some analysts predict industry
profits of around $4 billion to $10 billion. In addition, Boeing has
reported a number of recent cancellations of orders for the fuel-
efficient 787 Dreamliner. According to one expert we met with, when
airlines are low on cash, they are unlikely to undertake improvements
that will reduce their fuel consumption and emissions, even if the
savings from fuel reductions will ultimately be greater than the cost
of the improvement because they have so little cash. This expert said,
for example, that although it may make financial sense for airlines to
engage in additional nonsafety-related engine maintenance to reduce
fuel burn and emissions, they may not do so because they lack
sufficient cash.
Although some airlines may adopt technologies to reduce their future
emissions, these efforts may not be enough to mitigate the expected
growth in air traffic and related increase in overall emissions through
2050. Although IPCC's forecast, as mentioned earlier, assumes future
technological improvements leading to annual improvements in fuel
efficiency, it excludes or doesn't account for the possibility that
some airlines might adopt biofuels or other potential breakthrough
technologies. Nonetheless, even if airlines adopt such technologies,
some experts believe that emissions will still be higher in 2050 under
certain conditions than they were in 2000. One expert we met with did a
rough estimate of future emissions from aircraft assuming the adoption
of many low-carbon technologies such as blended wing-body, operational
improvements, and biofuels. He used IPCC's midrange forecast of
emissions to 2050 as a baseline for future traffic and found that even
assuming the introduction of these technologies, global emissions in
2050 would continue to exceed 2000 emissions levels.[Footnote 48] Had a
lower baseline of emissions been used, forecasted emissions may have
been lower. He acknowledged that more work needs to be done in this
area. Another study by a German research organization modeled future
emissions assuming the adoption of technological improvements, as well
as biofuels, to reduce emissions. This study assumed future traffic
growth averaging 4.8 percent between 2006 and 2026 and 2.6 percent
between 2027 and 2050.[Footnote 49] While this study forecasted
improvements in emissions relative to expected market growth, it
estimated that by 2050 total emissions would still remain greater than
2000 emissions levels.
Governments Can Use a Variety of Policy Options to Help Reduce
Commercial Aircraft Emissions, but the Costs and Benefits of Each Vary:
Governments have a number of policy options--including policies that
set a price on emissions, market-based measures like a cap-and-trade
program or a tax, regulatory standards, and funding for research and
development--they could use to help reduce greenhouse gas emissions
from commercial aviation and other sectors of the economy. The social
benefits (for example, resulting from emissions reductions) and costs
associated with each option vary, and the policies may affect
industries and consumers differently. However, economic research
indicates that market-based policies are more likely to better balance
the benefits and costs of achieving reductions in greenhouse gases and
other emissions (or, in other words, to be more economically
efficient). In addition, research and development spending could
complement market-based measures or standards to help facilitate the
development and deployment of low-emissions technologies. However,
given the relatively small current and forecasted percentage of global
emissions generated by the aviation sector, actions taken to reduce
aviation emissions alone, and not emissions from other sectors, could
be costly and have little potential impact on reducing global
greenhouse gas emissions.[Footnote 50]
Market-Based Policies Could Be Used to Provide Airlines and Other
Sources with an Economic Incentive to Reduce Greenhouse Gas Emissions:
Economists and other experts we interviewed stated that establishing a
price on greenhouse gas emissions through market-based policies, such
as a cap-and-trade program or a tax on emissions from commercial
aircraft and other sources, would provide these sources with an
economic incentive to reduce their emissions. Generally, a cap-and-
trade program or an emissions tax (for example, on carbon dioxide) can
achieve emissions reductions at less cost than other policies because
they would give firms and consumers the flexibility to decide when and
how to reduce their emissions. Many experts we surveyed said that
establishing a price on emissions through a cap-and-trade program or a
tax would help promote the development and adoption of a number of low-
emissions technologies for airlines, including open rotor engines and
blended wing-body aircraft. Another market-based policy, subsidy
programs, such as a payment per unit of emissions reduction, can in
principle provide incentives for firms and consumers to reduce their
greenhouse gas emissions. However, subsidy programs need to be
financed--for example through existing taxes or by raising taxes--and
can create perverse incentives resulting in higher emissions.
Cap-and-Trade Program:
One market-based option for controlling emissions is a cap-and-trade
program. Also known as an emissions trading program, a cap-and-trade
program would limit the total amount of emissions from regulated
sources. These sources would receive, from the government, allowances
to emit up to a specific limit--the "cap." The government could sell
the allowances through an auction or provide them free of charge (or
some combination of the two). In addition, the government would
establish a market under which the regulated sources could buy and sell
allowances with one another. Sources that can reduce emissions at the
lowest cost could sell their allowances to other sources with higher
emissions reduction costs. In this way, the market would establish an
allowance price, which would represent the price of carbon dioxide (or
other greenhouse gas) emissions. Generally, according to economists, by
allowing sources to trade allowances, policy makers can achieve
emissions reductions at the lowest cost.
A cap-and-trade program can be designed to cap emissions at different
points in the economy. For example, a cap-and-trade program could be
designed to cap "upstream" sources like fuel processors, extractors,
and importers. Under this approach, a cap would be set on the emissions
potential that is inherent in the fossil fuel. The upstream cap would
restrain the supply and increase the prices of fossil fuels and thus
the price of jet fuel relative to less carbon-intensive alternatives.
Alternatively, under a "downstream" program, direct emitters, such as
commercial airlines, would be required to hold allowances equal to
their total carbon emissions each year. (See figure 9.) However,
economic research indicates that both types of programs would provide
commercial airlines with an incentive to reduce their fuel consumption
in the most cost-effective way for each airline, such as by reducing
weight, consolidating flights, or using more fuel-efficient aircraft,
if they were included in such a program. To the extent that airlines
would pass along any program costs to customers through higher
passenger fares and shipping rates, travelers and shippers could
respond in various ways, including by traveling less frequently or
using a different, cheaper transportation mode.[Footnote 51]
Figure 9: A Potential Cap-and-Trade Program Regulating Airlines and
Other Emissions Sources:
[Refer to PDF for image: illustration]
Airline A: Airline A exceeds their emissions allowances and purchases
allowances from other airlines and industries;
Airline B: Airline B makes low-cost emissions reductions and sells its
excess allowances to Airline A.
Factory: This factory makes low-cost emissions reductions and sells its
excess allowances to airline A.
Government:
Provides for allowances and auctioned allowance to Airline A, Airline B
and Factory.
Source: GAO.
[End of figure]
The effectiveness of a cap-and-trade program in balancing the benefits
and costs of the emission reductions could depend on factors included
in its design. Generally, by establishing an upper limit on total
emissions from regulated sources, a cap-and-trade program can provide
greater certainty than other policies (for example, an emissions tax)
that emissions will be reduced to the desired level. Regulated sources
would be required to hold allowances equal to their total emissions,
regardless of the cost. However, allowance prices could be volatile,
depending on factors such as changes in energy prices, available
technologies, and weather,[Footnote 52] making it more expensive for
sources to meet the cap. To limit price volatility, a cost-containment
mechanism called a "safety valve" could be incorporated into the cap-
and-trade program to establish a ceiling on the price of allowances.
For example, if allowance prices rose to the safety-valve price, the
government could sell regulated sources as many allowances as they
would like to buy at the safety-valve price.[Footnote 53] Although the
safety valve could limit price spikes, the emissions cap would be
exceeded if the safety valve were triggered.
In addition, the baseline that is used to project future emissions and
set the emissions cap can affect the extent to which a cap-and-trade
program will contain or reduce emissions.[Footnote 54] The point in
time on which a baseline is set also can influence the environmental
benefits of a cap-and-trade program. For example, some environmental
interest groups in Europe have claimed that the environmental benefits
of including aviation in the EU ETS will be minimal, since the
emissions cap will be based on the mean average of aviation emissions
from 2004 through 2006, leading to minimal future emissions reductions.
[Footnote 55]
In addition, industry groups and other experts have raised concerns
that a cap-and-trade program could be administratively burdensome to
the government, which would need to determine how to allocate the
allowances to sources, oversee allowance trading, and monitor and
enforce compliance with the program. Generally speaking, an upstream
program may have lower administrative costs than a downstream program
because it would likely involve fewer emissions sources.
Some members of the aviation industry have said they view open and
global cap-and-trade programs positively, although they report that not
all types of cap-and-trade programs will work for them. For instance,
ICAO and other industry organizations have said they would prefer an
open cap-and-trade program (in which airlines are allowed to trade
allowances with other sectors and sources) to a closed one (in which
airlines are allowed to trade emissions allowances only with one
another) because an open program would give airlines more flexibility
in meeting their emissions cap. Staff we met with at the Association of
European Airlines expressed willingness for aviation to participate in
a cap-and-trade program as long as it is global in scope, is an open
system, is not in addition to similar taxes, and does not double-count
emissions.[Footnote 56] In addition, some industry groups and
government agencies we met with said that a global program would best
ensure that all airlines would take part in reducing emissions.
Cap-and-Trade Plans and Legislation:
Some countries are planning to address aviation emissions through cap-
and-trade programs. The European Union originally implemented the EU
ETS in 2005, covering industries representing about 50 percent of its
carbon dioxide emissions.[Footnote 57] The EU is planning on including
all covered flights by aircraft operators flying into or out of EU
airports, starting in 2012.[Footnote 58] Please see appendix I for more
details on the EU ETS, including a comprehensive discussion of the
potential legal implications and stakeholders' positions on this new
framework. Other countries are considering cap-and-trade programs that
would affect the aviation sector.[Footnote 59]
In addition, the United States is currently considering and has
previously considered cap-and-trade programs:
* H.R. 2454, the American Clean Energy and Security Act of 2009, 111th
Cong. (2009), would create a cap-and-trade program for greenhouse gas
emissions for entities responsible for 85 percent of emissions in the
United States. The current language proposes to regulate producers and
importers of any petroleum-based liquid fuel, including aircraft fuel,
as well as other entities, and calls for an emissions cap in 2050 that
would be 83 percent lower than 2005 emissions. The bill also calls for
the emissions cap in 2012 to be 3 percent below 2005 levels, and in
2020 to be 20 percent below 2005 levels. In addition, the Obama
Administration's fiscal year 2010 budget calls for the implementation
of a cap-and-trade program to regulate emissions in the United States.
The budget calls for emissions reductions so that emissions in 2020 are
14 percent below 2005 levels and emissions in 2050 are 83 percent below
2005 levels.
* Additionally in this Congress, the Cap and Dividend Act,[Footnote 60]
also proposes a cap-and-trade program for carbon dioxide emissions
beginning in 2012, which would include jet fuel emissions. This
program's covered entities would include entities that would make the
first sale in U.S. markets of oil or a derivative product used as a
combustible fuel, including jet fuel. The bill would require the
Secretary of the Treasury, in consultation with the EPA Administrator,
to establish the program's emission caps in accordance with the
following targets: the 2012 cap would equal 2005 emissions; the 2020
cap would equal 75 percent of 2005 emissions; the 2030 cap would equal
55 percent of 2005 emissions; the 2040 cap would equal 35 percent of
2005 emissions; and the 2050 cap would equal 15 percent of 2005
emissions.
* A number of bills creating a cap-and-trade program also were
introduced in the 110th Congress but did not pass. For example, a bill
sponsored by Senators Boxer, Warner, and Lieberman would have
established a cap-and-trade program that covered petroleum refiners and
importers, among other entities.[Footnote 61] The costs of the
regulation would have been borne by these refiners and importers who
would likely have passed on those costs to airlines through increases
in the price of jet fuel.
Emissions Taxes:
An emissions tax is another market-based policy that could be used to
reduce emissions from commercial aviation and other emissions sources.
Under a tax on carbon dioxide (or other greenhouse gas), the government
would levy a fee for every ton of carbon dioxide emitted. Similar to a
cap-and-trade program, a tax would provide a price signal to commercial
airlines and other emission sources, creating an economic incentive for
them to reduce their emissions. A carbon tax could be applied to
"upstream" sources such as fuel producers, which may in turn pass along
the tax in the form of higher prices to fuel purchasers, including
commercial airlines. Similar to a cap-and-trade program, emissions
taxes would provide regulated sources including commercial airlines
with an incentive to reduce emissions in the most cost-effective way,
which might include reducing weight, consolidating flights, or using
more fuel-efficient aircraft.
According to economic theory, an emissions tax should be set at a level
that represents the social cost of the emissions.[Footnote 62]
Nonetheless, estimates of the social costs associated with greenhouse
gas emissions vary. For example, IPCC reported that the social costs of
damages associated with greenhouse gas emissions average about $12 per
metric ton[Footnote 63] of carbon dioxide (in 2005 dollars) with a
range of $3 to $95 per ton (in 2005 dollars).
Economic research indicates that an emissions tax is generally a more
economically efficient policy tool to address greenhouse gas emissions
than other policies, including a cap-and-trade program, because it
would better balance the social benefits and costs associated with the
emissions reductions. In addition, compared to a cap-and-trade program,
an emissions tax would provide greater certainty as to the price of
emissions. However, it would in concept provide less certainty about
emissions reductions because the reductions would depend on the level
of the tax and how firms and consumers respond to the tax.[Footnote 64]
Subsidies:
Subsidies are another market-based instrument that could, in principle,
provide incentives for sources to reduce their emissions. For example,
experts we met with said that the government could use subsidies to
encourage industry and others to adopt existing low-emissions
technologies and improvements, such as winglets. In addition, some
experts told us that NextGen-related technologies are candidates for
subsidies because of the high costs of the technologies and the
benefits that they will provide to the national airspace system.
According to IPCC, subsidies can encourage the diffusion of new low-
emissions technologies and can effectively reduce emissions. For
example, as newer, more fuel-efficient engines are developed and become
commercially available, subsidies or tax credits could lower their
relative costs and encourage airlines to purchase them.
Although subsidies are similar to taxes, economic research indicates
that some subsidy programs can be economically inefficient, and need to
be financed (for example, using current tax revenue or by raising
taxes). For example, although some subsidy programs could lead to
emissions reductions from individual sources, they may also result in
an overall increase by encouraging some firms to remain in business
longer than they would have under other policies such as an emissions
tax.
Distribution of Costs under Market-based Measures:
Both a cap-and-trade program and an emissions tax would impose costs on
the aviation sector and other users of carbon-based fuels. The extent
to which the costs associated with an emissions control program are
incurred by commercial airlines and passed on will depend on a number
of economic factors, such as the level of market competition and the
responsiveness of passengers to changes in price. Officials of some
industry organizations we met with said that because airlines are in a
competitive industry with a high elasticity of demand,[Footnote 65]
they are constrained in passing on their costs, and the costs to
industry likely will be large. The Association of European Airlines
reported that airlines will have very limited ability to pass on the
costs of the EU ETS. Furthermore, the International Air Transport
Association has estimated that the costs to the industry of complying
with the EU ETS will be €3.5 billion in 2012,[Footnote 66] with annual
costs subsequently increasing.[Footnote 67] Others we interviewed,
however, stated that airlines will be able to pass on costs, and the
increases in ticket prices will not be large. For example, the EU
estimates that airlines will be able to pass on most of the costs of
their compliance with the EU ETS, which will result in an average
ticket price increase of €9 on a medium-haul flight.[Footnote 68]
However, the revenue generated by the tax or by auctioning allowances
could be used to lessen the overall impact on the economy, or the
impact on certain groups (for example, low income) or sectors of the
economy by, for example, reducing other taxes.[Footnote 69]
Finally, according to some airline industry representatives, a program
to control greenhouse gas emissions would add to the financial burden
the aviation industry and its consumers already face with respect to
other taxes and fees. For example, passenger tickets in the United
States are subject to a federal passenger ticket tax of 7.5 percent, a
segment charge of $3.40 per flight segment, and fees for security and
airport facilities (up to $4.50 per airport). In addition,
international flights are subject to departure taxes and customs-
related fees. However, none of these taxes and fees attempt to account
for the cost of greenhouse gas emissions, as a tax or cap-and-trade
program would do. In addition, the revenue generated from an emissions
tax or by auctioning allowances under a cap-and-trade program, could be
used to offset other taxes, thereby lessening the economic impact of
the program.
Emissions Standards Could Limit Emissions from Specific Technologies,
but Are Generally Not an Economically Efficient Approach for Reducing
Greenhouse Gas Emissions:
Mandating the use of certain technologies or placing emissions limits
on aircraft and aircraft engines are also potential options for
governments to address aircraft emissions. Standards include both
technology standards, which mandate a specific control technology such
as a particular fuel-efficient engine, and performance standards, which
may require polluters to meet an emissions standard using any available
method. The flexibility in the performance standards reduces the cost
of compliance compared with technology-based standards and, according
to DOT, avoids potential aviation safety implications that may occur
from forcing a specific technology across a wide range of operations
and conditions.
For example, by placing a strict limit on aircraft emissions, a
standard would limit the emissions levels from an engine or aircraft.
Regulations on specific emissions have been used to achieve specific
environmental goals. ICAO's nitrogen oxide standards place limits on
nitrogen oxide emissions from newly certified aircraft engines. These
standards were first adopted in 1981 and became effective in 1986.
Although no government has yet promulgated standards on aircraft carbon
dioxide emissions or fuel economy, emissions standards are being
discussed within ICAO's Committee on Aviation Environmental Protection
and, in December 2007, a number of environmental interest groups filed
petitions with EPA asking the agency to promulgate regulations for
greenhouse gas emissions from aircraft and aircraft engines. In
addition, the American Clean Energy and Security Act of 2009 would
require EPA to issue standards for greenhouse gas emissions from new
aircraft and new engines used in aircraft by December 31, 2012.
[Footnote 70]
Although standards can be used to limit greenhouse gas emissions levels
from aircraft, economic research indicates that they generally are not
as economically efficient as market-based instruments because they do
not effectively balance the benefits and costs associated with the
emissions reductions.[Footnote 71] For example, unlike market-based
instruments, technology standards would give engine manufacturers
little choice about how to reduce emissions and may not encourage them
to find cost effective ways of controlling emissions.[Footnote 72] In
addition, according to IPCC, because technology standards may require
emissions to be reduced in specified ways, they may not provide the
flexibility to encourage industry to search for other options for
reducing emissions. However, according to EPA, performance standards to
address certain emissions from airlines, such as those adopted by ICAO
and EPA, gave manufacturers flexibility in deciding which technologies
to use to reduce emissions.[Footnote 73] Nonetheless, although
performance standards can provide greater flexibility and therefore be
more cost-effective than technology standards, economic research
indicates that standards generally provide sources with fewer
incentives to reduce emissions beyond what is required for compliance,
compared to market-based approaches. Moreover, standards typically
apply to new, rather than existing, engines or aircraft, making new
engines or aircraft more expensive, and as a result, the higher costs
may delay purchases of more fuel-efficient aircraft and engines.
Current international aviation standards also may require international
cooperation. Because ICAO sets standards for all international aviation
issues, it may be difficult for the U.S. government, or any national
government, to set a standard that is not adopted by ICAO, although
member states are allowed to do so. Industry groups we met with said
that any standards should be set through ICAO and then adopted by the
United States and other nations and, as mentioned earlier, some
environmental groups have petitioned EPA to set such standards.
Government-Sponsored Research and Development Can Help Encourage the
Development and Adoption of Low-Emissions Technologies, but May Be
Costly to Governments:
Government-sponsored research into low-fuel consumption and low-
emissions technologies can help foster the development of such
technologies, particularly in combination with a tax or a cap-and-trade
program. Experts we surveyed said that increased government research
and development could be used to encourage a number of low-emissions
technologies, including open rotor engines and blended wing-body
aircraft. According to the Final Report of the Commission on the Future
of the United States Aerospace Industry, issued in 2002, the lack of
long-term investments in aerospace research is inhibiting innovation in
the industry and economic growth. This study also asserted that
national research and development on aircraft emissions is small when
compared with the magnitude of the problem and the potential payoffs
that research drives. Experts we met with said that government
sponsorship is crucial, especially for long-term fundamental research,
because private companies may not have a sufficiently long-term
perspective to engage in research that will result in products for
multiple decades into the future. According to one expert we
interviewed, the return on investment is too far off into the future to
make it worthwhile for private companies. NASA officials said that
private industry generally focuses only on what NASA deems the "next
generation conventional tube and wing technologies," which are usually
projected no more than 20 years into the future. Furthermore, raising
fuel prices or placing a price on emissions through a tax or cap-and-
trade program is likely to encourage greater research by both the
public and private sectors into low-emissions technologies because it
increases the pay off associated with developing such technologies.
Various U.S. federal agencies, including NASA and FAA, have long been
involved in research involving low-emissions technologies.[Footnote 74]
For example, NASA's subsonic fixed-wing research program is devoted to
the development of technologies that increase aircraft performance, as
well as reduce both noise levels and fuel burn. Through this program,
NASA is researching a number of different technologies to achieve those
goals, including propulsion, lightweight materials, and drag reduction.
The subsonic fixed-wing program is looking to develop three generations
of aircraft with increasing degrees in technology development and fuel
burn improvements--the next-generation conventional tube and wing
aircraft, the unconventional hybrid wing-body aircraft, and advanced
aircraft concepts.[Footnote 75] NASA follows goals set by the National
Plan for Aeronautics Research and Development and Related
Infrastructure for fuel efficiency improvements[Footnote 76] for each
of these generations (see table 6).[Footnote 77]
Table 6: NASA's Subsonic Fixed-Wing Research Fuel-Reduction Goals:
Aircraft fuel burn reduction goal:
Research generation: Next generation tube and wing: 33 percent fuel
reduction (relative to Boeing 737);
Research generation: Unconventional hybrid wing-body: 40 percent fuel
reduction (relative to Boeing 777);
Research generation: Advanced aircraft concepts: Better than 70 percent
fuel reduction.
Time frame:
Research generation: Next generation tube and wing: 2015;
Research generation: Unconventional hybrid wing-body: 2020;
Research generation: Advanced aircraft concepts: 2030-2035.
Source: NASA.
[End of table]
However, budget issues may affect NASA's research schedule. As we have
reported, NASA's budget for aeronautics research was cut by about half
in the decade leading up to fiscal year 2007, when the budget was $717
million.[Footnote 78] Furthermore, NASA's proposed fiscal year 2010
budget calls for significant cuts in aeronautics research, with a
budget of $569 million. As NASA's aeronautics budget has declined, it
has focused more on fundamental research and less on demonstration
work. However, as we have reported, NASA and other officials and
experts agree that federal research and development efforts are an
effective means of achieving emissions reductions in the longer
term.[Footnote 79] According to NASA officials, the research budget for
its subsonic fixed-wing research program, much of which is devoted to
technologies to reduce emissions and improve fuel efficiency, will be
about $69 million in 2009.
FAA has proposed creating a new research consortium to focus on
emissions and other issues. Specifically, FAA has proposed the
Consortium for Lower Energy, Emissions, and Noise, which would fund, on
a 50-50 cost share basis with private partners, research and advanced
development into low-emissions and low-noise technologies, including
alternative fuels, over 5 years. FAA plans that the consortium will
mature technologies to levels that facilitate uptake by the aviation
industry. The consortium contributes to the goal set by the National
Plan for Aeronautics, Research and Development and Related
Infrastructure to reduce fuel burn by 33 percent compared with current
technologies. The House FAA Reauthorization Bill (H.R. 915, 111th Cong.
(2009)) would provide up to $108 million in funding for the consortium
for fiscal years 2010 through 2012.
Lastly, the EU has two major efforts dedicated to reducing aviation
emissions. The Advisory Council for Aeronautics Research in Europe
(ACARE) is a collaborative group of governments and manufacturers
committed to conducting strategic aeronautics research in Europe.
According to officials with the European Commission Directorate General
of Research, about €150 million to €200 million per year[Footnote 80]
is devoted to basic research through ACARE. Another research effort in
Europe is the Clean Sky Joint Technology Initiative, which will
provide €1.6 billion[Footnote 81] over 7 years to fund various
demonstration technologies.
Agency Comments and Our Evaluation:
We provided a draft copy of this report to the Department of Defense,
the Department of State, the Department of Transportation, the National
Aeronautics and Space Administration, and the Environmental Protection
Agency for their review.
The Department of Defense had no comments. The Department of State
provided comments via email. These comments were technical in nature
and we incorporated them as appropriate.
The Department of Transportation provided comments via email. Most of
these comments were technical in nature and we incorporated them as
appropriate. In addition, DOT stated that our statements indicating
that the use of future technological and operational improvements may
not be enough to offset expected emissions growth is not accurate given
the potential adoption of alternative fuels. We agree that alternative
fuels do have potential to reduce aircraft emissions in the future; to
the extent that a low-emission (on a life-cycle basis) alternative fuel
is available in substantial quantities for the aviation industry,
emissions from the aviation industry are likely to be less than they
otherwise would be. However, we maintain that given concerns over the
potential environmental impacts of alternative fuels, including their
life-cycle emissions, as well as the extent to which such fuels are
available in adequate supplies at a competitive price, there may be a
somewhat limited potential for alternative fuel use to reduce emissions
from commercial aircraft in the future, especially the short term. DOT
also suggested that we clarify the sources for our discussion about
policy options that can be used to address aviation emissions. As much
of that discussion is based on economic research and experience with
market-based instruments and other policies, we clarified our sources
where appropriate.
NASA provided a written response (see appendix V) in which they stated
that our draft provided an accurate and balanced view of issues
relating to aviation and climate change. NASA also provided technical
comments that were incorporated as appropriate. EPA provided technical
comments via email that were incorporated as appropriate and also
provided a written response. (see appendix VI).
EPA was concerned that characterizing aircraft emissions standards as
being economically inefficient especially compared to market-based
measures, might lead readers to believe that emissions standards cannot
be designed in a manner that fosters technological innovations and
economic efficiency. EPA officials explained that, based on their
experience, standards can be designed to optimize technical responses,
provide regulated entities with flexibility for compliance and that
studies show that EPA regulations have generated benefits in excess of
costs. We agree that allowing regulated sources more flexibility in how
they meet emissions standards can reduce the costs associated with
achieving the emissions reductions. However, economic research
indicates that for addressing greenhouse gas emissions, market-based
measures such as emissions taxes or cap-and-trade programs would be
economically efficient (that is, would maximize net benefits) compared
to other approaches, in part because market-based measures can give
firms and consumers more flexibility to decide when and how to reduce
their emissions. Emissions standards, for example, generally give
regulated sources fewer incentives to reduce emissions beyond what is
required for compliance. The ultimate choice of what specific policy
option or combination of options governments might use and how it
should be designed is a complex decision and beyond the scope of our
discussion.
Finally, EPA was concerned that our draft report did not adequately
discuss the increases in fuel consumption and emissions that have
resulted from high rates of market growth and expected continued
growth. We believe that our report adequately discusses fuel efficiency
as well as fuel consumption and emissions output. In addition, our
report discusses that aviation emissions are expected to grow in the
long term, despite the potential availability of a number of
technological and operational options that can help increase fuel
efficiency. In response to this comment, we added additional
information on forecasted fuel use by U.S.-based commercial airlines.
We are sending copies of this report to the Secretaries of Defense,
State, and Transportation and the Administrators of the Environmental
Protection Agency and the National Aeronautics and Space
Administration. This report is also available at no charge on the GAO
Web site at [hyperlink, http://www.gao.gov].
If you or your staffs have any questions concerning this report, please
contact me at (202) 512-2834 or flemings@gao.gov. Contact points for
our Offices of Congressional Relations and Public Affairs may be found
on the last page of this report. Staff members making key contributions
to this report are listed in appendix VII.
Signed by:
Susan Fleming:
Director, Physical Infrastructure Issues:
List of Congressional Requesters:
The Honorable Bart Gordon:
Chairman:
The Honorable Ralph Hall:
Ranking Member:
Committee on Science and Technology:
House of Representatives:
The Honorable James L. Oberstar:
Chairman:
The Honorable John L. Mica:
Ranking Member:
Committee on Transportation and Infrastructure:
House of Representatives:
The Honorable Jerry F. Costello:
Chairman:
The Honorable Thomas E. Petri:
Ranking Member:
Subcommittee on Aviation:
Committee on Transportation and Infrastructure:
House of Representatives:
[End of section]
Appendix I: Legal Implications of European Union Emissions Trading
Scheme:
The European Union's recent decision to include aviation in the
European Union's Emissions Trading Scheme (EU ETS), which includes U.S.
carriers flying in and out of Europe, is a complex and controversial
matter. Preparations by U.S. carriers are already underway for 2012,
the first year aircraft operators will be included in the ETS. The
inclusion of aviation in the current EU ETS implicates a number of
international treaties and agreements and has raised concerns among
stakeholders both within and outside the United States. Many
stakeholders within the United States have posed that the inclusion of
aviation in the ETS violates provisions of these international
agreements and is contrary to international resolutions. Others,
primarily in Europe, disagree and find aviation's inclusion in the
current ETS to be well within the authority set forth in these
agreements. In light of these disagreements, the EU may confront a
number of hurdles in attempting to include U.S. carriers in the current
EU ETS framework.
EU ETS Law:
In 2005, the EU implemented its ETS, a cap-and-trade program to control
carbon dioxide emissions from various energy and industrial sectors. On
December 20, 2006, the European Commission set forth a legislative
proposal to amend the law, or directive, which established the ETS so
as to include aviation in the ETS.[Footnote 82] On July 8, 2008, the
European Parliament adopted the legislative resolution of the European
Council and on October, 24, 2008, the Council adopted the directive,
signaling its final approval.[Footnote 83] The directive was published
in the Official Journal on January 13, 2009, and became effective on
February 2, 2009.[Footnote 84]
Under the amended ETS Directive, beginning on January 1, 2012, a cap
will be placed on total carbon dioxide emissions from all covered
flights by aircraft operators flying into or out of an EU airport.
[Footnote 85] Emissions will be calculated for the entire flight.
[Footnote 86] For 2012, the cap for all carbon dioxide emissions from
covered flights will be set at 97 percent of historical aviation
emissions.[Footnote 87] For the 2013-2020 trading period and subsequent
trading periods, the cap will be set to reflect annual emissions equal
to 95 percent of historical aviation emissions.[Footnote 88]
The cap represents the total quantity of emissions allowances available
for distribution to aircraft operators. In 2012 and each subsequent
trading period, 15 percent of allowances must be auctioned to aircraft
operators; the remaining allowances will be distributed to these
aircraft operators for free based on a benchmarking process.[Footnote
89] Individual member states, in accordance with the EU regulation,
will conduct the auctions for aircraft operators assigned to that
member state.[Footnote 90] The auction of allowances will be open for
anyone to participate. The number of allowances each member state has
to auction depends on its proportionate share of the total verified
aviation emissions for all member states for a certain year.[Footnote
91] The member states will be able to use the revenues raised from
auctions in accordance with the amended directive.[Footnote 92] For
each trading period, aircraft operators can apply to their assigned
member state to receive free allowances. Member states will allocate
the free allowances in accordance with a process the European
Commission establishes for each trading period.
After the conclusion of each calendar year, aircraft operators must
surrender to their assigned member state a number of allowances equal
to their total emissions in that year. If an aircraft operator's
emissions exceed the number of free allowances it receives, it will be
required to purchase additional allowances at auction or on the trading
market for EU ETS allowances.[Footnote 93] In addition, in 2012,
aircraft operators will be able to submit certified emissions
reductions (CER) and emission reduction units (ERU)--from projects in
other countries undertaken pursuant to the Kyoto Protocol's Clean
Development Mechanism and Joint Implementation--to cover up to 15
percent of their emissions in lieu of ETS allowances. For subsequent
trading periods, aircraft operators' use of CERs and ERUs depends in
part on whether a new international agreement on climate change is
adopted. However, regardless of whether such an agreement is reached,
in the 2013 through 2020 trading period, each aircraft operator will be
allowed to use CERs and ERUs to cover at least 1.5 percent of their
emissions.[Footnote 94]
If a country not participating in the EU ETS adopts measures for
reducing the climate change impact of flights to participating
countries, then the European Commission, in consultation with that
country, will consider options to provide for "optimal interaction"
between the ETS and that country's regulatory scheme--for example, the
Commission may consider excluding from the ETS flights to participating
EU ETS countries from that country.[Footnote 95] Although 2012 is the
first year aircraft operators must comply with the ETS law,
preparations in the EU[Footnote 96] and from U.S. carriers[Footnote 97]
began soon after the law went into force.
Legal Implications of the ETS:
The inclusion of aviation in the newly amended EU ETS implicates a
number of international agreements, policy statements, and a bilateral
agreement specific to the United States, including the United Nations
Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol to
the UNFCCC, the Convention on International Civil Aviation (the
'Chicago Convention'), Resolutions of the International Civil Aviation
Organization, and the U.S.-EU Air Transport Agreement (the 'U.S.-EU
Open Skies Agreement').
The UNFCCC, a multilateral treaty on global warming that was signed in
1992 and has been ratified by 192 countries, including the United
States, seeks to "achieve stabilization of greenhouse gas
concentrations in the atmosphere at a level that would prevent
dangerous anthropogenic interference with the climate system."[Footnote
98] Although the UNFCCC required signatory states to formulate a
national response to climate change,[Footnote 99] its mitigation
provisions did not require mandatory national emissions targets.
[Footnote 100]
In order to strengthen the commitments articulated in the UNFCCC, the
Kyoto Protocol was developed within the UNFCCC's framework and adopted
in 1997. The Protocol entered into force in February 2005.[Footnote
101] The Kyoto Protocol established binding greenhouse gas emissions
targets for a number of industrialized nations[Footnote 102] and the
European Economic Community (EEC).[Footnote 103] Notably, the agreement
required these industrialized nations and the EEC to pursue
"limitations or reduction of emissions of greenhouse gases...from
aviation...working through the International Civil Aviation
Organization."[Footnote 104] As of January 2009, 183 countries had
ratified the Kyoto Protocol, but not the United States.
Further, the Convention on International Civil Aviation, commonly known
as the Chicago Convention, signed on December 7, 1944, sets forth rules
on airspace, issues of sovereignty, aircraft licensing and
registration, and general international standards and procedures, among
others.[Footnote 105] Notably, the treaty sets forth sovereignty
provisions, recognizing that a contracting state has exclusive
sovereignty over airspace above its own territory.[Footnote 106]
Provisions potentially applicable to the recent amendment incorporating
aviation into the ETS include Article 11,[Footnote 107] Article 12,
[Footnote 108] Article 15,[Footnote 109] and Article 24.[Footnote 110]
Established by the Chicago Convention in 1944, the International Civil
Aviation Organization (ICAO) is an agency of the United Nations and is
tasked with fostering the planning and development of international
aviation. ICAO has issued a number of Assembly Resolutions, which are
statements of policy rather than law, including a nonbinding ICAO
Resolution A36-22 relating to environmental protection and aviation
emissions.[Footnote 111] This resolution, which supersedes ICAO
Resolution A35-5 which had endorsed the further development of an open
emissions trading scheme for international aviation, calls for mutual
agreement between contracting states before implementation of an
emissions trading scheme.[Footnote 112] Additionally, the Resolution
formed a new Group on International Aviation and Climate Change (GIACC)
that was tasked with developing and recommending to the ICAO Council a
program of action to address international aviation and climate change.
[Footnote 113] GIACC is due to report to the Council later this year.
Finally, the U.S.-EU Air Transport Agreement,[Footnote 114] signed on
April 25 and 30, 2007, and provisionally applied as of March 30, 2008,
provided greater flexibility for flights between the United States and
the EU, authorizing every U.S. and every EU airline to: operate without
restriction on the number of flights, aircraft, and routes, set fares
according to market demand; and enter into cooperative arrangements,
including codesharing, franchising, and leasing. It includes enhanced
opportunities for EU investment in carriers from almost 30 non-EU
countries, and enhanced regulatory cooperation in regard to competition
law, government subsidies, the environment, consumer protection, and
security.[Footnote 115] Among the provisions potentially applicable to
the newly amended EU ETS is Articles 12 relating to charges for use of
airports and related facilities and services and Article 3 which
prohibits a party from unilaterally limiting service or aircraft type.
[Footnote 116]
Although a number of international agreements, policy statements, and
bilateral agreements are in place currently, climate change policies
are constantly changing. In December 2009, the Conference of the
Parties to the UNFCCC will meet in Copenhagen to discuss and negotiate
an "agreed outcome" in order to implement the UNFCCC "up to and beyond
2012."[Footnote 117]
Stakeholder Positions on Legal Issues:
A number of stakeholders have expressed concern as to the legal basis
for aviation's inclusion in the EU ETS. In the United States, within
the EU community, and in countries throughout the world, public and
private entities, as well as legal scholars, have expressed opinions as
to whether the inclusion of aviation into the ETS is in compliance with
international law.
Stakeholder Positions within the United States:
Stakeholders within the United States, such as the executive branch,
members of Congress, and the Air Transport Association (ATA), have
weighed in on the legality of the newly amended EU ETS which requires
compliance by U.S. carriers.
In 2007 and 2008, the executive branch expressed the view that the
imposition of the ETS was inconsistent with international law,
specifically, the Chicago Convention and the U.S.-EU Air Transport
Agreement.[Footnote 118] While the executive branch has not articulated
a position on this issue since mid-2008, it has expressed the
importance of climate change and developing a solution on a global
level.[Footnote 119]
The Air Transport Association (ATA), a trade association representing
principle U.S. airlines, also has concluded that the EU ETS's inclusion
of aviation violates international law, specifically the Chicago
Convention.[Footnote 120] ATA argues that imposition of the ETS on U.S.-
based carriers is contrary to Articles 1, 12, 11,[Footnote 121] 15
[Footnote 122] and potentially, in the alternative, Article 24.
[Footnote 123] In summary, ATA argues that the ETS, as amended,
violates Article 1 and Article 12 provisions of sovereignty and
authority. Article 1, which provides contracting states exclusive
sovereignty over their airspace,[Footnote 124] is violated by the EU's
extraterritorial reach which covers emissions of non-EU airlines in
another states' airspace. Further, Article 12, which requires
contracting states to ensure that aircraft under its jurisdiction are
in compliance with rules and regulations relating to the flight and
maneuver of aircraft,[Footnote 125] also is violated. ATA argues that
Article 12 gives ICAO primary authority, under the Convention, to set
rules for the "flight and maneuver of aircraft" over the "high seas,"
which precludes the application of rules by one state over the airlines
of another state to the extent inconsistent with ICAO rules. Thus,
because ICAO has stated that one state can apply emissions trading to
the airlines of another state only through mutual consent, ATA contends
that the EU's emissions trading coverage of non-agreeing-EU airlines
over the high seas is inconsistent with ICAO's authority.
Additionally, with respect to Article 11, ATA argues that although
Article 11 provides authority to states to establish certain rules for
admission and departure of aircraft, the authority is limited. States
may only establish admission and departure rules consistent with the
remainder of the Chicago Convention, which prevents the EU from arguing
that Article 11 authorizes EU action. In any event, ATA contends that
any rules may only apply "upon entering or departing from or while
within the territory of that State," whereas the European scheme
reaches outside European territory. Further, ATA finds that the ETS is
contrary to Article 15[Footnote 126] of the Chicago Convention because
it imposes a de facto charge for the right to enter or exit an EU
member state. In the alternative, ATA argues that there could be a
violation of Article 24 of the Convention, which exempts fuel on board
an aircraft from duties, fees, and charges. Because the law calculates
emissions based on fuel consumption, the purchase of greenhouse gas
permits may constitute a "similar — charge" of fuel on board, according
to ATA. Additionally, Article 24 mirrors Article 11 of the U.S.-EU Air
Transport Agreement but extends the freedom from taxation/charges on
fuel to that purchased in the EU. Thus, ATA argues, the prohibition
against the EU levying a fuel tax applies to fuel already on board as
well as fuel purchased in the EU.
ATA has publicly expressed harsh opposition to the ETS's inclusion of
aviation and has stated that there will be a number of legal challenges
from around the globe, including from the United States.[Footnote 127]
ATA has additionally expressed discontent with the newly amended ETS
law as a matter of policy, as it siphons money out of aviation which is
counterproductive from reinvesting in improving technologies that
reduce emissions.[Footnote 128]
Finally, the Congress is considering the House FAA Reauthorization
Bill, H.R. 915, 111th Cong. (2009), which includes an expression of the
Sense of the Congress with respect to the newly amended EU
ETS.[Footnote 129] The bill states that the EU's imposition of the ETS,
without working through ICAO, is inconsistent with the Chicago
Convention, other relevant air service agreements, and "antithetical to
building cooperation to address effectively the problem of greenhouse
gas emissions by aircraft engaged in international civil aviation."
[Footnote 130] The bill recommends working through ICAO to address
these issues.[Footnote 131]
Stakeholder Positions outside the United States:
Stakeholders in the EU community and a not-for-profit business
organization have expressed both legal and policy views on the newly
amended ETS, as well. An independent contractor for the European
Commission's Directorate-General of the Environment (DG Environment) as
well as the International Emissions Trading Association (IETA) have
both issued opinions in support of aviation's inclusion in the ETS.
[Footnote 132] IETA supports the inclusion of aviation in the EU ETS
from a policy perspective, but has not opined on the legality of its
inclusion.[Footnote 133] From a policy standpoint, IETA supports
aviation's inclusion on both EU and non-EU carriers so as to share the
burden to combat climate change.[Footnote 134] However, the
organization has expressed concerns over a number of issues, some of
which include access to project credits, amount of allowances available
for auctioning, and allocation calculation.[Footnote 135]
From a legal perspective, an independent contractor for the DG
Environment[Footnote 136] has issued an opinion supporting aviation's
inclusion in the EU ETS.[Footnote 137] The opinion states that
alongside a state's inherent right to enact legislation and the
provisions of the EC Treaty for collective action by member states, the
legal basis for action is contained in the UNFCCC's requirement for
developed countries to take measures to mitigate climate change, in the
Kyoto Protocol which reinforces this position, and under EU law (the EC
Treaty), which provides the basis for the EU to act by including
aviation in the ETS.[Footnote 138] Further, the opinion articulates
that the ETS does not violate Articles 11,[Footnote 139] 12,[Footnote
140] 15,[Footnote 141] or 24[Footnote 142] of the Chicago Convention.
First, Article 11 is consistent with the newly amended ETS law so long
as the "laws and regulations" established do not "discriminate as to
nationality of aircraft."[Footnote 143] Further, Article 12 is
inapplicable because emissions trading does not affect the flight or
maneuver of aircraft but merely the terms for admission to and
departure from EU territory. Additionally, the opinion stated that
Article 15 is inapplicable because the coverage of aviation cannot be
seen as an "airport charge or similar charge." Even if payment were to
occur under an auction system, the allowances are not designed as
compensation for the costs of operation and management of airports and
air navigation facilities, and consequently, Article 15 is
inapplicable.[Footnote 144] Finally, Article 24 of the Convention does
not apply to the Emissions Trading System because trading allowances
are "fundamentally different from customs duties."[Footnote 145]
Additionally, the opinion finds policy support for these legal findings
in ICAO Resolution A35-5[Footnote 146] and bilateral air transport
agreements.[Footnote 147]
Additionally, countries outside the European Community have joined the
United States in an expression of concerns regarding the imposition of
the ETS on non-EU carriers. In an April 2007 letter to the German
Ambassador to the European Union, the United States, Australia, China,
Japan, South Korea, and Canada conveyed a "deep concern and strong
dissatisfaction" for the then-proposal to include international civil
aviation within the scope of the EU ETS.[Footnote 148] The letter asks
that the EU ETS not include non-EU aircraft unless done by mutual
consent.[Footnote 149] Although supportive of the reduction of
greenhouse gas emissions, the ascribing parties argue that the
"unilateral" imposition of the ETS on non-EU carriers would potentially
violate the Chicago Convention and bilateral aviation agreements with
the parties to the letter.[Footnote 150] Moreover, they write, the
proposal runs counter to the international consensus that ICAO should
handle matters of international aviation, which was articulated with
the ICAO Assembly and the ICAO Council in 2004 and 2006,
respectively.[Footnote 151] The letter closes with a reservation of
right to take appropriate measures under international law if the ETS
is imposed.[Footnote 152]
Legal Scholar/Researcher Views:
Given the controversial nature and complexity of aviation's inclusion
in the EU ETS, a number of scholars in the legal community, both within
the United States and the EU, have provided explanatory articles or
position papers on the issue of the consistency of the EU's plans with
its international legal obligations.[Footnote 153]
One U.S. law review article by Daniel B. Reagan argues that
international aviation emission reductions should be pursued through
ICAO given the "political, technical, and legal implications raised by
the regulation."[Footnote 154] This article sets forth that
politically, ICAO is the appropriate body because it can work towards
uniformity in a complex regulatory arena, incidentally resulting in
increased participation from a variety of stakeholders, reduction of
resentment, and a reduced likelihood of non-compliance and legal
challenges.[Footnote 155] Further, ICAO has the expertise necessary to
technically design aviation's emission reduction regime and is in a
position to consider the "economic, political, and technical
circumstances of its member states..."[Footnote 156] Finally, Reagan
argues that pursuing an emissions reduction regime through ICAO could
avoid likely legal challenges which present themselves under the
current ETS, as ICAO could facilitate a common understanding of
contentious provisions.[Footnote 157] In conclusion, he proposes that
the EU should channel the energy for implementation of the current
regime into holding ICAO accountable for fulfilling environmental
duties.[Footnote 158]
In contrast, a law review article published in the European
Environmental Law Review in 2007 by Gisbert Schwarze argues that
bringing aviation into the EU ETS falls clearly within existing law and
is, in fact, mandated.[Footnote 159] The article presents the case that
neither existing traffic rights in member states, bilateral air
transport agreements, nor the Chicago Convention pose any legal
obstacles.[Footnote 160] He argues, in fact, that the EU has a mandate
under the UNFCCC and the Kyoto Protocol to implement climate change
policies which include aviation. First, the article sets forth that the
inclusion of aviation does not restrict existing traffic rights or
allow or disallow certain aircraft operations in different member
states, but rather merely brings the amount of emissions into the
decision-making process.[Footnote 161]
Further, Schwarze explains that imposing the ETS on carriers flying in
and out of the EU is well within the Chicago Convention. Article 1 of
the Convention provides contracting states exclusive sovereignty over
their airspace which provides the EU with the authority to impose
obligations relating to arrival and departures, so long as there is no
discrimination on the basis of nationality, as required by Article 11.
[Footnote 162] Additionally, the article sets forth that Article 12,
regarding the flight and maneuver of aircraft, is not applicable
because, as argued above, the ETS does not regulate certain aircraft
operations. Article 15, which covers charges, is similarly inapplicable
because emissions allowances on the free market or through the
auctioning process do not constitute a charge.[Footnote 163] Finally,
Article 24 is inapposite as well because the emissions trading system
does not constitute a customs duty.[Footnote 164]
Additionally, Schwarze argues that the bilateral air transport
agreements with various nations, such as the Open Skies Agreement with
the United States, do not pose any legal barriers to inclusion of
aviation in ETS.[Footnote 165] These agreements contain a prohibition
of discrimination similar to Article 11 of the Chicago Convention and a
fair competition clause which requires fair competition among
signatories in international aviation as well as prohibits a party from
unilaterally limiting traffic.[Footnote 166] The article argues that so
long as the ETS operates without discrimination, it is in conformity
with the principle of a sound and economic operation of air services
and therefore satisfies the fairness clause.[Footnote 167] Finally,
since the ETS gives only incentive to reduce emissions, it does not
regulate the amount of air traffic.[Footnote 168]
Finally, Schwarze argues that not only is the inclusion of aviation
into the EU ETS legally sound, the UNFCCC and Kyoto Protocol mandate
its inclusion. The UNFCCC requires all parties to the treaty to adopt
national policies and take corresponding measures on the mitigation of
climate change consistent with the objective of the convention,
recognizing that this can be done "jointly with other parties."
[Footnote 169] Additionally, the Kyoto Protocol, which sought to
strengthen UNFCCC, required Annex 1 parties to pursue "limitations or
reduction of emissions of greenhouse gases — from aviation — working
through the International Civil Aviation Organization."[Footnote 170]
And finally, although not legally binding, ICAO Resolution A35-5
endorses the development of an open emissions trading system for
international aviation.[Footnote 171]
Potential Legal Challenges and Dispute Resolution:
Implementation of the new ETS directive will likely face legal
challenges before 2012, the first year aircraft operators will be
included in the ETS. A number of stakeholders, including ATA, have
publicly expressed that there will be "government-to-government legal
challenges" and potentially a "multilateral challenge from around the
world."[Footnote 172] Further, countries outside the EU community have
joined in support of taking appropriate actions under international law
if the ETS is imposed.[Footnote 173] If challenges are brought forth,
they could potentially be brought forth under the Chicago Convention,
air service agreements (e.g., U.S.-EU Air Transport Agreement) or
potentially in individual member state courts. Each option has its own
dispute resolution procedure.
If a challenge is brought forth under the Chicago Convention after
failed negotiations, Article 84 of the Convention (Settlement of
Disputes) is invoked. Article 84 provides that if there is a
disagreement by two or more contracting states which cannot be settled
by negotiation, it will be decided upon by the Council.[Footnote 174] A
decision by the Council can be appealed to an agreed-upon ad hoc
tribunal or to the Permanent Court of International Justice (now the
International Court of Justice) whose decision will be binding.
[Footnote 175]
Air service agreements additionally have dispute resolution procedures
and the U.S.-EU Air Transport Agreement is no exception. Article 19 of
the U.S.-EU Air Transport Agreement provides that parties to a dispute
may submit to binding arbitration through an ad hoc tribunal if
negotiations fail.[Footnote 176] If there is noncompliance with the
tribunal's decision and a subsequent agreement between the parties is
not reached within 40 days, the other party may suspend the application
of comparable benefits which arise under the agreement.[Footnote 177]
In addition to bringing legal challenges under international treaties,
carriers could potentially mount legal challenges in member states'
national courts, according to some legal scholars.[Footnote 178]
Additionally, a European state will potentially be able to take action
against a noncompliant carrier under their civil aviation authority in
the state's courts.[Footnote 179]
[End of section]
Appendix II: List of Experts:
Gerald Bernstein, Stanford Transportation Group:
Dennis Bushnell, National Aeronautics and Space Administration:
Kenneth Button, George Mason University:
Anthony Dean, General Electric:
Robert Deering, American Airlines:
Christian Dumas, Airbus (France):
Jasper Faber, CE Delft (Netherlands):
Richard Golaszewski, GRA, Incorporated:
Preston Henne, Gulfstream Aerospace Corporation:
James Hileman, Massachusetts Institute of Technology:
Jennifer Holmgren, Universal Oil Products:
David Lee, Manchester Metropolitan University (United Kingdom):
Peter Morrell, Cranfield University (United Kingdom):
Andreas Schafer, University of Cambridge (United Kingdom):
Agam Sinha, MITRE Corporation:
Julian Tishkoff, United States Air Force:
Ian Waitz, Massachusetts Institute of Technology:
Donald Wuebbles, University of Illinois:
[End of section]
Appendix III: Detailed Survey Results:
The survey tool used to assess options for reducing commercial aircraft
emissions is below, complete with detailed results. We do not include
the responses for open-ended questions.
United States Government Accountability Office:
Aviation and Climate Change:
Ranking Tool for Options to Reduce Aircraft Greenhouse Gas Emissions:
Introduction:
This rating tool follows up on our recent interview with you on
commercial aviation and greenhouse gas emissions. The tool contains
options for reducing commercial aviation emissions that were identified
through our interviews with you and other experts, or by GAO. We have
placed the options in three categories--technologies, operations, and
alternative fuels--and are interested in your expert opinion on them.
We ask that you rate the options across several factors, providing
comments where appropriate.
Instructions for Completing This Tool:
You can answer most of the questions by checking boxes or filling in
blanks. A few questions request short narrative answers. Please note
that these blanks will expand to fit your answer.
* Please use your mouse to navigate throughout the document by clicking
on the field or checking the box you wish to fill in. Do not use the
"Tab" or "Enter" keys, because doing so may cause formatting problems.
* To select a box, click on it once; to deselect a box, double click on
it.
If you prefer, you may print this tool, complete it by hand, and return
it by fax. Please use extra paper as necessary to complete the open-
ended questions.
Deadline:
We ask that you complete and return this document to Matthew Rosenberg
by January 9, 2009. Please save the completed document to your desktop
or hard drive and e-mail it as an attachment to RosenbergMC@gao.gov. If
you complete this tool by hand, please fax the completed tool to
Matthew Rosenberg at GAO at 312-220-7726.
Contact Information:
If you have any questions, please contact Matthew Rosenberg, Senior
Analyst, at 312-220-7645 or RosenbergMC@gao.gov or Cathy Colwell,
Assistant Director, at 312-220-7655 or ColwellC@gao.gov.
Thank you for your help.
Part 1: Technology Options:
1. How would you rate your overall knowledge of technological options
to reduce aircraft carbon dioxide (CO2) emissions, such as aircraft
engines and aircraft design technologies, and the costs of those
technologies?
0; None: Skip To Question #9:
6; Minimal: Skip To Question #9:
4; Basic: Continue To Question #2:
1; Proficient: Continue To Question #2:
7; Advanced: Continue To Question #2:
2. In your expert opinion, what is the potential for future fuel
savings and CO2 emissions reductions for the following options?
a. Open rotor engines;
Low potential: 0;
Medium potential: 5;
High potential: 8;
Don't know: 1.
b. Geared Turbo Fan Engines;
Low potential: 2;
Medium potential: 7;
High potential: 3;
Don't know: 2.
c. Distributive Propulsion systems;
Low potential: 2;
Medium potential: 2;
High potential: 5;
Don't know: 5.
d. Lighter airframes (Composites);
Low potential: 2;
Medium potential: 5;
High potential: 6;
Don't know: 1.
e. Increased Laminar Flow Control;
Low potential: 2;
Medium potential: 6;
High potential: 3;
Don't know: 2.
f. Blended wing-body aircraft;
Low potential: 0;
Medium potential: 5;
High potential: 8;
Don't know: 1.
g. Winglets;
Low potential: 8;
Medium potential: 3;
High potential: 3;
Don't know: 0.
h. Riblets;
Low potential: 9;
Medium potential: 1;
High potential: 0;
Don't know: 4.
[End of table]
3. In your expert opinion, what would be the potential R&D costs to
develop the following options for commercial use?
a. Open rotor engines;
Low costs: 1;
Medium costs: 6;
High costs: 6;
Don't know: 1.
b. Geared Turbo Fan Engines;
Low costs: 3;
Medium costs: 7;
High costs: 3;
Don't know: 1.
c. Distributive Propulsion systems;
Low costs: 0;
Medium costs: 1;
High costs: 7;
Don't know: 6.
d. Lighter airframes (Composites);
Low costs: 1;
Medium costs: 6;
High costs: 6;
Don't know: 1.
e. Increased Laminar Flow Control;
Low costs: 0;
Medium costs: 4;
High costs: 7;
Don't know: 3.
f. Blended wing-body aircraft;
Low costs: 1;
Medium costs: 1;
High costs: 12;
Don't know: 0.
g. Winglets;
Low costs: 14;
Medium costs: 0;
High costs: 0;
Don't know: 0.
h. Riblets;
Low costs: 7;
Medium costs: 3;
High costs: 0;
Don't know: 4.
4. Given your answer to question two, what would be the potential costs
to the air transport industry to procure, operate and maintain the
following options to achieve those fuel savings and CO2 emissions
reductions?
a. Open rotor engines;
Low costs: 2;
Medium costs: 7;
High costs: 3;
Don't know: 2.
b. Geared Turbo Fan Engines;
Low costs: 2;
Medium costs: 9;
High costs: 1;
Don't know: 2.
c. Distributive Propulsion systems;
Low costs: 0;
Medium costs: 2;
High costs: 6;
Don't know: 6.
d. Lighter airframes (Composites);
Low costs: 3;
Medium costs: 6;
High costs: 3;
Don't know: 2.
e. Increased Laminar Flow Control;
Low costs: 1;
Medium costs: 4;
High costs: 5;
Don't know: 4.
f. Blended wing-body aircraft;
Low costs: 2;
Medium costs: 3;
High costs: 9;
Don't know: 0.
g. Winglets;
Low costs: 14;
Medium costs: 0;
High costs: 0;
Don't know: 0.
h. Riblets;
Low costs: 9;
Medium costs: 1;
High costs: 0;
Don't know: 4.
5. In your expert opinion, what is the level of public acceptance for
the following conceptual options?
a. Open rotor engines;
Low acceptance: 6;
Medium acceptance: 7;
High acceptance: 0;
Don't know: 1.
b. Geared Turbo Fan Engines;
Low acceptance: 0;
Medium acceptance: 2;
High acceptance: 11;
Don't know: 1.
c. Distributive Propulsion systems;
Low acceptance: 2;
Medium acceptance: 2;
High acceptance: 4;
Don't know: 6.
d. Lighter airframes (Composites);
Low acceptance: 0;
Medium acceptance: 3;
High acceptance: 9;
Don't know: 2.
e. Increased Laminar Flow Control;
Low acceptance: 0;
Medium acceptance: 4;
High acceptance: 8;
Don't know: 2.
f. Blended wing-body aircraft;
Low acceptance: 4;
Medium acceptance: 5;
High acceptance: 2;
Don't know: 3.
g. Winglets;
Low acceptance: 0;
Medium acceptance: 0;
High acceptance: 13;
Don't know: 1.
h. Riblets;
Low acceptance: 0;
Medium acceptance: 1;
High acceptance: 9;
Don't know: 4.
6. In your expert opinion, given our best knowledge about future market
conditions, and absent government intervention, how long would it take
for the private sector to adopt these technologies?
a. Open rotor engines;
Short timeframe (< 5 years): 1;
Medium timeframe (5 - 15 years): 9;
Long timeframe (> 15 years): 3;
Never: 0;
Don't know: 1.
b. Geared Turbo Fan Engines;
Short timeframe (< 5 years): 6;
Medium timeframe (5 - 15 years): 6;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 2.
c. Distributive Propulsion systems;
Short timeframe (< 5 years): 0;
Medium timeframe (5 - 15 years): 0;
Long timeframe (> 15 years): 6;
Never: 2;
Don't know: 6.
d. Lighter airframes (Composites);
Short timeframe (< 5 years): 3;
Medium timeframe (5 - 15 years): 9;
Long timeframe (> 15 years): 1;
Never: 0;
Don't know: 1.
e. Increased Laminar Flow Control;
Short timeframe (< 5 years): 2;
Medium timeframe (5 - 15 years): 4;
Long timeframe (> 15 years): 5;
Never: 0;
Don't know: 3.
f. Blended wing-body aircraft;
Short timeframe (< 5 years): 0;
Medium timeframe (5 - 15 years): 2;
Long timeframe (> 15 years): 10;
Never: 2;
Don't know: 0.
g. Winglets;
Short timeframe (< 5 years): 14;
Medium timeframe (5 - 15 years): 0;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 0.
h. Riblets;
Short timeframe (< 5 years): 5;
Medium timeframe (5 - 15 years): 3;
Long timeframe (> 15 years): 1;
Never: 0;
Don't know: 5[A].
7. What major challenges exist to widespread use of:
a. Open rotor engines:
b. Geared Turbo Fan Engines:
c. Distributive Propulsion systems:
d. Lighter airframes (Composites):
e. Increased Laminar Flow Control:
f. Blended wing-body aircraft:
g. Winglets:
h. Riblets:
8. What actions could the U.S. federal government undertake to promote
the development and/or adoption of:
a. Open rotor engines:
b. Geared Turbo Fan Engines:
c. Distributive Propulsion systems:
d. Lighter airframes (Composites):
e. Increased Laminar Flow Control:
f. Blended wing-body aircraft:
g. Winglets:
h. Riblets:
Part 2: Operational Options:
9. How would you rate your overall knowledge of operational options to
reduce aircraft fuel usage and CO2 emissions, such as air traffic
management and airline operations?
0; None: Skip To Question #17:
5; Minimal: Skip To Question #17:
7; Basic: Continue To Question #10:
4; Proficient: Continue To Question #10:
2; Advanced: Continue To Question #10:
10. In your expert opinion, what is the future potential for fuel
savings and CO2 emissions reductions for the following options?
a. Reduction of on-board weight;
Low potential: 7;
Medium potential: 4;
High potential: 2;
Don't know: 0.
b. Engine washing;
Low potential: 8;
Medium potential: 4;
High potential: 0;
Don't know: 1.
c. Limited use of paint on airframes;
Low potential: 9;
Medium potential: 3;
High potential: 0;
Don't know: 1.
d. Increased engine maintenance;
Low potential: 8;
Medium potential: 3;
High potential: 1;
Don't know: 1.
e. Single engine taxing;
Low potential: 7;
Medium potential: 6;
High potential: 0;
Don't know: 0.
f. Use of APU on ground at gate;
Low potential: 10;
Medium potential: 2;
High potential: 0;
Don't know: 1.
g. Automatic Dependent Surveillance - Broadcast (ADS-B);
Low potential: 2;
Medium potential: 6;
High potential: 1;
Don't know: 4.
h. Required Navigation Performance (RNP);
Low potential: 2;
Medium potential: 4;
High potential: 2;
Don't know: 5.
i. Continuous Descent Arrivals (CDA);
Low potential: 5;
Medium potential: 5;
High potential: 2;
Don't know: 1.
j. NEXTGEN Weather;
Low potential: 3;
Medium potential: 5;
High potential: 1;
Don't know: 4.
k. Enhanced vision systems;
Low potential: 6;
Medium potential: 3;
High potential: 0;
Don't know: 4.
l. Synthetic vision systems;
Low potential: 6;
Medium potential: 2;
High potential: 0;
Don't know: 5.
m. Reduced Vertical Separation;
Low potential: 3;
Medium potential: 8;
High potential: 1;
Don't know: 1.
n. Flying at slower speeds;
Low potential: 5;
Medium potential: 5;
High potential: 3;
Don't know: 0.
o. Formation flying;
Low potential: 5;
Medium potential: 2;
High potential: 2;
Don't know: 4.
p. Air to air refueling;
Low potential: 7;
Medium potential: 1;
High potential: 0;
Don't know: 5.
q. Reduced flight frequency with larger aircraft;
Low potential: 6;
Medium potential: 3;
High potential: 3;
Don't know: 1.
r. Multi-stage long distance travel;
Low potential: 6;
Medium potential: 4;
High potential: 1;
Don't know: 2.
11. In your expert opinion, what would be the potential R&D costs to
develop the following options for commercial use?
a. Reduction of on-board weight;
Low Costs: 8;
Medium Costs: 4;
High Costs: 1;
Don't know: 0.
b. Engine washing;
Low Costs: 11;
Medium Costs: 0;
High Costs: 0;
Don't know: 2.
c. Limited use of paint on airframes;
Low Costs: 13;
Medium Costs: 0;
High Costs: 0;
Don't know: 0.
d. Increased engine maintenance;
Low Costs: 11;
Medium Costs: 2;
High Costs: 0;
Don't know: 0.
e. Single engine taxing;
Low Costs: 13;
Medium Costs: 0;
High Costs: 0;
Don't know: 0.
f. Use of APU on ground at gate;
Low Costs: 11;
Medium Costs: 0;
High Costs: 0;
Don't know: 2.
g. Automatic Dependent Surveillance - Broadcast (ADS-B);
Low Costs: 1;
Medium Costs: 6;
High Costs: 1;
Don't know: 5.
h. Required Navigation Performance (RNP);
Low Costs: 3;
Medium Costs: 4;
High Costs: 0;
Don't know: 6.
i. Continuous Descent Arrivals (CDA);
Low Costs: 4;
Medium Costs: 7;
High Costs: 0;
Don't know: 2.
j. NEXTGEN Weather;
Low Costs: 1;
Medium Costs: 4;
High Costs: 3;
Don't know: 5.
k. Enhanced vision systems;
Low Costs: 2;
Medium Costs: 5;
High Costs: 1;
Don't know: 5.
l. Synthetic vision systems;
Low Costs: 2;
Medium Costs: 5;
High Costs: 1;
Don't know: 5.
m. Reduced Vertical Separation;
Low Costs: 9;
Medium Costs: 1;
High Costs: 1;
Don't know: 2.
n. Flying at slower speeds;
Low Costs: 13;
Medium Costs: 0;
High Costs: 0;
Don't know: 0.
o. Formation flying;
Low Costs: 3;
Medium Costs: 3;
High Costs: 4;
Don't know: 3.
p. Air to air refueling;
Low Costs: 0;
Medium Costs: 3;
High Costs: 5;
Don't know: 5.
q. Reduced flight frequency with larger aircraft;
Low Costs: 12;
Medium Costs: 0;
High Costs: 1;
Don't know: 0.
r. Multi-stage long distance travel;
Low Costs: 11;
Medium Costs: 0;
High Costs: 1;
Don't know: 1.
12. Given your answer to question ten, what would be the potential
costs to the air transport industry to adopt the following options to
achieve those fuel savings and CO2 emissions reductions?
a. Reduction of on-board weight;
Low costs: 8;
Medium costs: 5;
High costs: 0;
Don't know: 0.
b. Engine washing;
Low costs: 8;
Medium costs: 4;
High costs: 0;
Don't know: 1.
c. Limited use of paint on airframes;
Low costs: 11;
Medium costs: 2;
High costs: 0;
Don't know: 0.
d. Increased engine maintenance;
Low costs: 5;
Medium costs: 6;
High costs: 1;
Don't know: 1.
e. Single engine taxing;
Low costs: 13;
Medium costs: 0;
High costs: 0;
Don't know: 0.
f. Use of APU on ground at gate;
Low costs: 10;
Medium costs: 1;
High costs: 0;
Don't know: 2.
g. Automatic Dependent Surveillance - Broadcast (ADS-B);
Low costs: 2;
Medium costs: 4;
High costs: 2;
Don't know: 5.
h. Required Navigation Performance (RNP);
Low costs: 4;
Medium costs: 3;
High costs: 0;
Don't know: 6.
i. Continuous Descent Arrivals (CDA);
Low costs: 8;
Medium costs: 3;
High costs: 0; Don't know: 1.
j. NEXTGEN Weather;
Low costs: 2;
Medium costs: 3;
High costs: 1;
Don't know: 6.
k. Enhanced vision systems;
Low costs: 1;
Medium costs: 5;
High costs: 2;
Don't know: 5.
l. Synthetic vision systems;
Low costs: 1;
Medium costs: 6;
High costs: 1;
Don't know: 5.
m. Reduced Vertical Separation;
Low costs: 9;
Medium costs: 2;
High costs: 0;
Don't know: 2.
n. Flying at slower speeds;
Low costs: 11;
Medium costs: 2;
High costs: 0;
Don't know: 0.
o. Formation flying;
Low costs: 2;
Medium costs: 4;
High costs: 2;
Don't know: 5.
p. Air to air refueling;
Low costs: 0;
Medium costs: 4;
High costs: 5;
Don't know: 4.
q. Reduced flight frequency with larger aircraft;
Low costs: 9;
Medium costs: 1;
High costs: 3;
Don't know: 0.
r. Multi-stage long distance travel;
Low costs: 5;
Medium costs: 4;
High costs: 2;
Don't know: 2.
13. In your expert opinion, what is the level of public acceptance for
the following options?
Reduction of on-board weight;
Low acceptance: 0;
Medium acceptance: 5;
High acceptance: 8;
Don't know: 0.
Engine washing;
Low acceptance: 0;
Medium acceptance: 0;
High acceptance: 11;
Don't know: 2.
Limited use of paint on airframes;
Low acceptance: 1;
Medium acceptance: 2;
High acceptance: 10;
Don't know: 0.
Increased engine maintenance;
Low acceptance: 0;
Medium acceptance: 0;
High acceptance: 12;
Don't know: 1.
Single engine taxing;
Low acceptance: 0;
Medium acceptance: 2;
High acceptance: 11;
Don't know: 0.
Use of APU on ground at gate;
Low acceptance: 0;
Medium acceptance: 2;
High acceptance: 9;
Don't know: 2.
Automatic Dependent Surveillance - Broadcast (ADS-B);
Low acceptance: 0;
Medium acceptance: 0;
High acceptance: 9;
Don't know: 4.
Required Navigation Performance (RNP);
Low acceptance: 0;
Medium acceptance: 0;
High acceptance: 8;
Don't know: 5.
Continuous Descent Arrivals (CDA);
Low acceptance: 0;
Medium acceptance: 1;
High acceptance: 12;
Don't know: 0.
NEXTGEN Weather;
Low acceptance: 0;
Medium acceptance: 1;
High acceptance: 8;
Don't know: 4.
Enhanced vision systems;
Low acceptance: 0;
Medium acceptance: 1;
High acceptance: 9;
Don't know: 3.
Synthetic vision systems;
Low acceptance: 1;
Medium acceptance: 1;
High acceptance: 8;
Don't know: 3.
Reduced Vertical Separation;
Low acceptance: 1;
Medium acceptance: 6;
High acceptance: 6;
Don't know: 0.
Flying at slower speeds;
Low acceptance: 7;
Medium acceptance: 5;
High acceptance: 1;
Don't know: 0.
Formation flying;
Low acceptance: 8;
Medium acceptance: 3;
High acceptance: 1;
Don't know: 1.
Air to air refueling;
Low acceptance: 10;
Medium acceptance: 1;
High acceptance: 0;
Don't know: 2.
Reduced flight frequency with larger aircraft;
Low acceptance: 7;
Medium acceptance: 5;
High acceptance: 1;
Don't know: 0.
Multi-stage long distance travel;
Low acceptance: 8;
Medium acceptance: 3;
High acceptance: 0;
Don't know: 1.
14. In your expert opinion, given our best knowledge about future
market conditions, and absent government intervention, how long would
it take for the private sector to adopt these technologies?
a. Reduction of on-board weight;
Short timeframe (< 5 years): 8;
Medium timeframe (5 -15 years): 5;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 0.
b. Engine washing;
Short timeframe (< 5 years): 11;
Medium timeframe (5 - 15 years): 1;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 1.
c. Limited use of paint on airframes;
Short timeframe (< 5 years): 9;
Medium timeframe (5 -15 years): 4;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 0.
d. Increased engine maintenance;
Short timeframe (< 5 years): 12;
Medium timeframe (5 -15 years): 1;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 0.
e. Single engine taxing;
Short timeframe (< 5 years): 13;
Medium timeframe (5 -15 years): 0;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 0.
f. Use of APU on ground at gate;
Short timeframe (< 5 years): 8;
Medium timeframe (5 -15 years): 3;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 2.
g. Automatic Dependent Surveillance - Broadcast (ADS-B);
Short timeframe (< 5 years): 3;
Medium timeframe (5 -15 years): 5;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 5.
h. Required Navigation Performance (RNP);
Short timeframe (< 5 years): 6;
Medium timeframe (5 -15 years): 1;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 6.
i. Continuous Descent Arrivals (CDA);
Short timeframe (< 5 years): 7;
Medium timeframe (5 -15 years): 5;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 1.
j. NEXTGEN Weather;
Short timeframe (< 5 years): 2;
Medium timeframe (5 - 15 years): 5;
Long timeframe (> 15 years): 0;
Never: 0;
Don't know: 6.
k. Enhanced vision systems;
Short timeframe (< 5 years): 2;
Medium timeframe (5 -15 years): 5;
Long timeframe (> 15 years): 1;
Never: 0;
Don't know: 5.
l. Synthetic vision systems;
Short timeframe (< 5 years): 1;
Medium timeframe (5 -15 years): 4;
Long timeframe (> 15 years): 3;
Never: 0;
Don't know: 5.
m. Reduced Vertical Separation;
Short timeframe (< 5 years): 5;
Medium timeframe (5 -15 years): 6;
Long timeframe (> 15 years): 1;
Never: 0;
Don't know: 1.
n. Flying at slower speeds;
Short timeframe (< 5 years): 11;
Medium timeframe (5 -15 years): 0;
Long timeframe (> 15 years): 2;
Never: 0;
Don't know: 0.
o. Formation flying;
Short timeframe (< 5 years): 2;
Medium timeframe (5 - 15 years): 4;
Long timeframe (> 15 years): 4;
Never: 2;
Don't know: 1.
p. Air to air refueling;
Short timeframe (< 5 years): 0;
Medium timeframe (5 -15 years): 1;
Long timeframe (> 15 years): 8;
Never: 1;
Don't know: 3.
q. Reduced flight frequency with larger aircraft;
Short timeframe (< 5 years): 8;
Medium timeframe (5 -15 years): 3;
Long timeframe (> 15 years): 1;
Never: 1;
Don't know: 0.
r. Multi-stage long distance travel;
Short timeframe (< 5 years): 6;
Medium timeframe (5 -15 years): 1;
Long timeframe (> 15 years): 2;
Never: 2;
Don't know: 2.
15. What major challenges exist to widespread use of:
a. Reduction of on-board weight:
b. Engine washing:
c. Limited use of paint on airframes:
d. Increased engine maintenance:
e. Single engine taxing:
f. Use of APU on ground at gate:
g. Automatic Dependent Surveillance - Broadcast (ADS-B):
h. Required Navigation Performance (RNP):
i. Continuous Descent Arrivals (CDA):
j. NEXTGEN Weather:
k. Enhanced vision systems:
l. Synthetic vision systems:
m. Reduced Vertical Separation:
n. Flying at slower speeds:
o. Formation flying:
p. Air to air refueling:
q. Reduced flight frequency with larger aircraft:
r. Multi-stage long distance travel:
16. What actions could the U.S. federal government undertake to promote
the adoption of:
a. Reduction of on-board weight:
b. Engine washing:
c. Limited use of paint on airframes:
d. Increased engine maintenance:
e. Single engine taxing:
f. Use of APU on ground at gate:
g. Automatic Dependent Surveillance - Broadcast (ADS-B):
h. Required Navigation Performance (RNP):
i. Continuous Descent Arrivals (CDA):
j. NEXTGEN Weather:
k. Enhanced vision systems:
l. Synthetic vision systems:
m. Reduced Vertical Separation:
n. Flying at slower speeds:
o. Formation flying:
p. Air to air refueling:
q. Reduced flight frequency with larger aircraft:
r. Multi-stage long distance travel:
Part 3: Alternative Fuel Options:
17. How would you rate your overall knowledge of alternative fuel
options to reduce aircraft CO2 emissions, such as biofuels?
1; None: Skip To Question #25:
7; Minimal: Skip To Question #25:
2; Basic: Continue To Question #18:
3; Proficient: Continue To Question #18:
5; Advanced: Continue To Question #18:
18. In your expert opinion, compared to jet fuel currently in use, what
is the potential for future reduction of CO2 emissions (on a life-cycle
basis) for the following options?
a. Coal to liquid;
No potential: 7;
Low potential: 1;
Medium potential: 2;
High potential: 0;
Don't know: 0.
b. Fischer-Tropsch-treated feedstocks such as switchgrass;
No potential: 1;
Low potential: 3;
Medium potential: 3;
High potential: 3;
Don't know: 0.
c. Fischer-Tropsch-treated forest waste;
No potential: 1;
Low potential: 3;
Medium potential: 3;
High potential: 3;
Don't know: 0.
d. Fischer-Tropsch-treated municipal waste;
No potential: 1;
Low potential: 5;
Medium potential: 1;
High potential: 3;
Don't know: 0.
e. Hydotreated algae;
No potential: 0;
Low potential: 3;
Medium potential: 1;
High potential: 6;
Don't know: 0.
f. Hydrotreated Palm and Soy Oils;
No potential: 2;
Low potential: 3;
Medium potential: 3;
High potential: 1;
Don't know: 1.
g. Hydrotreated camelina;
No potential: 1;
Low potential: 2;
Medium potential: 3;
High potential: 2;
Don't know: 2.
h. Hydrotreated jatropha;
No potential: 0;
Low potential: 3;
Medium potential: 3;
High potential: 2;
Don't know: 2.
i. Fuel cells;
No potential: 6;
Low potential: 1;
Medium potential: 1;
High potential: 0;
Don't know: 1.
j. Hydrogen;
No potential: 4;
Low potential: 2;
Medium potential: 1;
High potential: 1;
Don't know: 1.
19. In your expert opinion, what would be the potential R&D costs to
develop the following options for commercial use?
a. Coal to liquid;
Low costs: 3;
Medium costs: 3;
High costs: 3;
Don't know: 1.
b. Fischer-Tropsch-treated feedstocks such as switchgrass;
Low costs: 1;
Medium costs: 3;
High costs: 4;
Don't know: 2.
c. Fischer-Tropsch-treated forest waste;
Low costs: 1;
Medium costs: 3;
High costs: 4;
Don't know: 2.
d. Fischer-Tropsch-treated municipal waste;
Low costs: 0;
Medium costs: 4;
High costs: 4;
Don't know: 2.
e. Hydotreated algae;
Low costs: 0;
Medium costs: 4;
High costs: 6;
Don't know: 0.
f. Hydrotreated Palm and Soy Oils;
Low costs: 2;
Medium costs: 3;
High costs: 3;
Don't know: 2.
g. Hydrotreated camelina;
Low costs: 2;
Medium costs: 3;
High costs: 2;
Don't know: 3.
h. Hydrotreated jatropha;
Low costs: 2;
Medium costs: 3;
High costs: 2;
Don't know: 3.
i. Fuel cells;
Low costs: 0;
Medium costs: 1;
High costs: 7;
Don't know: 2.
j. Hydrogen;
Low costs: 0;
Medium costs: 1;
High costs: 8;
Don't know: 1.
20. In your expert opinion, what is the level of public acceptance for
the following options?
a. Coal to liquid;
Low costs: 5;
Medium costs: 3;
High costs: 0;
Don't know: 2.
b. Fischer-Tropsch-treated feedstocks such as switchgrass;
Low costs: 0;
Medium costs: 3;
High costs: 6;
Don't know: 1.
c. Fischer-Tropsch-treated forest waste;
Low costs: 0;
Medium costs: 4;
High costs: 5;
Don't know: 1.
d. Fischer-Tropsch-treated municipal waste;
Low costs: 0;
Medium costs: 3;
High costs: 6;
Don't know: 1.
e. Hydotreated algae;
Low costs: 0;
Medium costs: 1;
High costs: 7;
Don't know: 2.
f. Hydrotreated Palm and Soy Oils;
Low costs: 5;
Medium costs: 1;
High costs: 2;
Don't know: 2.
g. Hydrotreated camelina;
Low costs: 0;
Medium costs: 5;
High costs: 2;
Don't know: 3.
h. Hydrotreated jatropha;
Low costs: 0;
Medium costs: 3;
High costs: 4;
Don't know: 3.
i. Fuel cells;
Low costs: 1;
Medium costs: 4;
High costs: 3;
Don't know: 2.
j. Hydrogen;
Low costs: 5;
Medium costs: 2;
High costs: 0;
Don't know: 3.
21. In your expert opinion, given our best knowledge about future
market conditions, and absent government intervention, how long would
it take for the private sector to adopt these technologies?
a. Coal to liquid;
ever: 7;
Short timeframe ( 20 years): 0;
Don't know: 1.
b. Fischer-Tropsch-treated feedstocks such as switchgrass;
Never: 5;
Short timeframe ( 20 years): 0;
Don't know: 1.
c. Fischer-Tropsch-treated forest waste;
Never: 5;
Short timeframe ( 20 years): 0;
Don't know: 1.
d. Fischer-Tropsch-treated municipal waste;
Never: 5;
Short timeframe ( 20 years): 0;
Don't know: 1.
e. Hydotreated algae;
Never: 3;
Short timeframe ( 20 years): 0;
Don't know: 1.
f. Hydrotreated Palm and Soy Oils;
Never: 5;
Short timeframe ( 20 years): 0;
Don't know: 2.
g. Hydrotreated camelina;
Never: 4;
Short timeframe ( 20 years): 0;
Don't know: 3.
h. Hydrotreated jatropha;
Never: 4;
Short timeframe ( 20 years): 0;
Don't know: 3.
i. Fuel cells;
Never: 0;
Short timeframe ( 20 years): 0;
Don't know: 1.
j. Hydrogen;
Never: 1;
Short timeframe ( 20 years): 1;
Don't know: 1.
22. What major challenges exist to widespread use of:
a. Coal to liquid:
b. Fischer-Tropsch-treated feedstocks such as switchgrass:
c. Fischer-Tropsch-treated forest waste:
d. Fischer-Tropsch-treated municipal waste:
e. Hydotreated algae:
f. Hydrotreated Palm and Soy Oils:
g. Hydrotreated camelina:
h. Hydrotreated jatropha:
i. Fuel cells:
j. Hydrogen:
23. What actions could the federal government undertake to promote the
development and/or adoption of:
a. Coal to liquid:
b. Fischer-Tropsch-treated feedstocks such as switchgrass:
c. Fischer-Tropsch-treated forest waste:
d. Fischer-Tropsch-treated municipal waste:
e. Hydotreated algae:
f. Hydrotreated Palm and Soy Oils:
g. Hydrotreated camelina:
h. Hydrotreated jatropha:
i. Fuel cells:
j. Hydrogen:
24. What other government actions, if any, should be undertaken to
address greenhouse gas emissions from commercial aircraft?
25. Do you have any other comments about anything covered in this
rating tool? If so, please comment here.
[End of section]
Appendix IV: Scope and Methodology:
To address our objectives, we interviewed selected officials
knowledgeable about the aviation industry, the industry's impact on the
production of greenhouse gas and other emissions that have an impact on
the climate, and options for reducing these emissions. We interviewed
federal officials from the Environmental Protection Agency (EPA), FAA,
the National Aeronautics and Space Administration (NASA) and the
Departments of Defense and State. We also met with representatives of
ICAO--a United Nations agency. We interviewed representatives of
industry groups, environmental groups, airlines, aircraft
manufacturers, aircraft engine manufacturers, alternative fuels
manufacturers, economists, and academics. We interviewed officials
based in the United States and abroad. We interviewed representatives
of the EU and associations about the EU ETS. We completed a literature
search and reviewed relevant documentation, studies, and articles
related to our objectives. To specifically address commercial
aviation's contribution to emissions, we asked our interviewees to
identify the primary studies that estimate current and future
emissions. As a result, we reviewed and summarized the findings of the
1999 International Panel of Climate Change Aviation and the Environment
report and its 2007 Fourth Assessment Report, which were most
frequently named as the most authoritative sources on global aviation
emissions.
To specifically address technological and operational options to reduce
commercial aviation's contribution to greenhouse gases and other
emissions that can have an impact on the climate, we contracted with
the National Academy of Sciences to identify and recruit experts in
aviation and environmental issues. We interviewed 18 experts identified
by the Academy, including those with expertise in aeronautics, air
traffic management, atmospheric science, chemistry, climate change
modeling, economics, environmental science, and transportation policy
[Footnote 180]. In conducting these interviews, we used a standardized
interview guide to obtain consistent answers from our experts and had
the interviews recorded and transcribed. Based on these interviews, we
assembled a list of options for reducing aviation emissions, and we
asked our experts to assess these options on several dimensions. We
provided each of our experts with a standardized assessment tool that
instructed the experts to assess the potential of each technological
and operational option on the following dimensions: potential fuel
savings and emissions reductions, potential research and development
costs, potential cost to the airline industry, potential for public
acceptance, and time frames for adoption. For each dimension, we asked
the experts to assess each option on a three-point scale. For example,
we asked the experts to rate each option as having "low potential",
"medium potential", or "high potential" [Footnote 181] for fuel savings
and carbon dioxide emissions reductions.[Footnote 182] We directed the
experts not to answer questions about areas in which they did not have
specific knowledge or expertise. As a result, throughout our report,
the number of expert responses discussed for each emissions reduction
option is smaller than 18, the number of experts we interviewed.
Besides asking the experts to assess the potential of technological
options, such as new aircraft and engine designs, we asked them to
assess the potential of alternative fuels to reduce carbon dioxide
emissions[Footnote 183]. Furthermore, for operational options we asked
the experts to assess included options that the federal government must
implement, such as air traffic management improvements, as well as
options that the airlines can exercise to reduce fuel burn. We analyzed
and summarized the experts' responses in order to identify those
technological and operational options that the experts collectively
identified as holding the most promise for reducing emissions. To
analyze the results, for each option and dimension, we counted the
numbers of experts that selected the "low," "medium," and "high"
responses. We then determined an overall, or group, answer for each
question based on the response the experts most commonly selected for
each option and dimension. However, if approximately the same number of
experts selected a second response, then we chose both responses as the
group answer. For example, rather than reporting that the experts rated
a particular option as having "high" potential, we instead reported
that they rated it as having "medium-high" potential if approximately
the same number of experts selected the "high" response as selected the
"medium" response. Finally, if approximately the same number of experts
selected all responses, then we determined that there was no consensus
on that question and reported the result as such.
In order to determine government options for reducing aviation
emissions, we interviewed relevant experts, including those 18
recruited by the National Academy of Sciences, about the potential use
and the costs and benefits of these options. We asked our interviewees
to provide opinions and information on a variety of governmental
options, including carbon taxes, cap-and-trade programs, aircraft and
engine standards, government-sponsored research, and governmental
subsidies. We looked at governmental actions that have been taken in
the past and at those that have been proposed. We reviewed economic
research on the economic impact of policy options for addressing
greenhouse gas emissions. Our review focused on whether policy options
could achieve emissions reductions from global sources in an
economically efficient manner (for example, maximize net benefits). We
interviewed EU officials to understand how the EU ETS will work and to
determine issues related to this scheme, which is slated to include
certain flights into and out of EU airports starting in 2012.
Additionally, we reviewed and summarized the EU ETS and the legal
implications of the scheme (see appendix I).
[End of section]
Appendix V: Comments from the National Aeronautics and Space
Administration:
National Aeronautics and Space Administration:
Headquarters:
Washington, DC 20546-0001:
May 26, 2009:
Reply to Attn of: Aeronautics Research Mission Directorate:
Ms. Cristina Chaplain:
Director, Acquisition and Sourcing Management:
United States Government Accountability Office:
Washington, DC 20548:
Dear Ms. Chaplain:
Thank you for the opportunity to review draft report, "Aviation and
Climate Change: Aircraft Emissions Expected to Grow, But Technical and
Operational Improvements and Government Policies Can Help Control
Emissions," (GAO-09-554).
We found the report to be complete, concise, and accurate. In our
opinion, it provides a balanced view of the issues related to the
potential of future impact of aircraft emissions on climate change.
Technical comments to the draft report have been provided separately.
Again, thank you for the opportunity to provide comments on the draft
report and for your continued interest in aviation and its affect on
climate change.
Sincerely,
Signed by:
Dr. Jaiwon Shin:
Associate Administrator for Aeronautics Research Mission Directorate:
cc: Matthew Rosenberg:
[End of section]
Appendix VI: Comments from the Environmental Protection Agency:
United States Environmental Protection Agency:
Office Of Air And Radiation:
Washington, D.C. 20460:
May 21, 2009:
Ms. Susan Fleming:
Director, Physical Infrastructure Issues:
U.S. Government Accountability Office (GAO):
441 G Street, N.W.
Washington, D.C. 20548:
Dear Ms. Fleming:
Thank you for the opportunity to review and comment on the draft
Government Accountability Office (GAO) report entitled, "Aviation and
Climate Change: Aircraft Emissions Expected to Grow but Technological
and Operational Improvements and Government Policies Can Help Control
Emissions," which was provided to the U.S. Environmental Protection
Agency (EPA) Administrator Lisa P. Jackson on May 1, 2009. We have
reviewed and commented substantially on two earlier statements of facts
related to this draft report.
While GAO has incorporated a portion of our written inputs on the
initial and revised drafts, there are two major points which we still
believe are not fully and correctly characterized within the report.
The first is related to the potential role of emission standards as
part of an overall response strategy and the second is related to the
characterization of jet fuel consumption.
The Role of Emission Standards:
The report fails to mention or discuss the extensive EPA Advanced
Notice of Proposed Rulemaking (ANPRM) on greenhouse gas control under
the Clean Air Act that was published in July 2008.[Footnote 1] We
strongly suggest this be referenced in the text. Further, we are
concerned about the characterization of the potential role of emission
standards in the underlined subtopic text on page 45 and the four
paragraphs which follow. The report expresses the view that potential
regulatory actions would limit technology responses and be economically
inefficient. Based on our 35 years of experience in setting and
implementing standards, we do not agree with this assessment. In fact,
past EPA rules clearly show that flexible regulatory programs can be
designed which optimize technology responses and yield benefits that
far outweigh costs.[Footnote 2]
Emission standards can be effectively used to limit emissions levels
from aircraft. For mobile sources, EPA emission standards are typically
not strict command and control requirements but are performance-based
standards (not design or technology specific requirements) which
provide manufacturers choices regarding which technology approaches to
use to reduce emissions. In addition, emission standards typically
include a variety of flexibility and incentive provisions to promote
technology options and improve their overall economic efficiency by
reducing costs.
These standards would include lead time and phase-in provisions (as in
current aviation emission standards) to allow the manufacturers
certainty and appropriate time to respond in the context of both market
forces and future business needs. In addition, as is the case in most
other EPA rules, they could include an emission averaging, banking, and
trading program and other important flexibility provisions to optimize
manufacturer technology response options, provide tools to improve
compliance certainty, and reduce costs. Appropriate engine emission
standards could drive measures for improved fuel specific fuel
consumption and airframe-related standards could also reduce greenhouse
gas emissions by improving efficiency. It now appears that the
International Civil Aviation Organization will be considering both the
engine and airframe approaches in the future and there is potential for
EPA to do the same. With the projected increase in jet fuel
consumption, achieving reductions in greenhouse gases will require
consideration of technology measures and potentially market-based
measures. Emission standards could in fact be complementary to the
effective implementation of a market-based program.
Jet Fuel Consumption:
Pages 4-7 discuss in detail the improved fuel efficiency of aviation
operations. Aviation fuel efficiency has indeed improved significantly
over the preceding three decades (see Figures 2 and 3 of the GAO
report). However, there is not adequate discussion of the fact that the
increase in aviation activity each year (more land-take-offs and more
flying hours) results in an increase in total jet fuel consumption that
has greatly outpaced the efficiency gains.
For example, according to data from the Air Transport Association,
between 1978 and 2007, efficiency (as measured on a gallons per
thousand revenue ton mile basis) improved by almost 110%.[Footnote 3]
However, according to information from the Bureau of Transportation
Statistics, annual jet fuel consumption rose by 95% over that same
period. As a result, jet fuel use was nine billion gallons higher in
2007 than in 1978.[Footnote 4] Despite these noteworthy efficiency
improvements, the annual Carbon Dioxide (CO2) inventory contribution
from aviation was 94 million tons greater in 2007 than in 1978. Looking
ahead, even with fleet turnover and the expected efficiency
improvements from engine, air frame, and air traffic system upgrades in
the future, the Federal Aviation Administration (FAA) projects an
increase in jet fuel consumption of 31% (1.6% per year) between 2008
and 2025.[Footnote 5] If these projections prove to be correct, the
aviation jet fuel consumption and carbon dioxide inventory contribution
from aviation will be 31% greater in 2025 than in 2008, and 150%
greater than in 1978.
Thank you for the opportunity to review and comment on this draft
report. We look forward to our continued interactions with GAO and
other stakeholders as we assess and consider policy options for
addressing greenhouse gas emissions from aviation.
Sincerely,
Signed by:
Elizabeth Craig:
Acting Assistant Administrator:
Footnotes (for Appendix V only):
[1] See the EPA Advance Notice of Proposed Rulemaking, "Regulating
Greenhouse Gas Emissions Under the Clean Air Act", published in the
Federal Register on July 30, 2008, 73 FR 44353.
[2] OMB has issued many Reports to Congress showing the economic
benefits of EPA rules (benefits to society outweighing costs), for
examples, see [hyperlink, http://www.whitehouse.gov/omb/intbreg/regpol-
reports_congress.html].
[3] See [hyperlink,
http://www.airlines.org/economics/energy/fuel+efficiencv.htm],
retrieved on May 15, 2009.
[4] See [hyperlink, http://www.transtats.bts.gov/fuel.asp?pn=1],
retrieved on May 15, 2009.
[5] See Table 22 from [hyperlink,
http://www.faa.gov/data_research/aviation/aerospace_forecasts/2009-
2025/media/2009%20Forecast%20Doc.pdf].
[End of section]
Appendix VII: GAO Contact and Staff Acknowledgments:
GAO Contact:
Susan Fleming, (202) 512-4431 or flemings@gao.gov:
Staff Acknowledgements:
In addition to the contact above, Cathy Colwell and Faye Morrison
(Assistant Directors), Lauren Calhoun, Kate Cardamone, Brad Dubbs,
Elizabeth Eisenstadt, Tim Guinane, Michael Hix, Sara Ann Moessbauer,
Josh Ormond, Tim Persons (Chief Scientist), Matthew Rosenberg, and Amy
Rosewarne made key contributions to this report.
The GAO staff that worked on this report dedicate it to their late
colleague, Jacqueline McFarlane, in recognition of the valuable
contributions she made:
[End of section]
Footnotes:
[1] Kyoto Protocol to the United Nations Framework Convention on
Climate Change (hereinafter the Kyoto Protocol). The Kyoto Protocol was
adopted in December 1997 and was open for signature between Mar. 16,
1998, and Mar. 15, 1999. As of Jan. 14, 2009, 183 countries and the EEC
had ratified the Kyoto Protocol. The binding emissions targets varies
by country and is generally higher for more highly developed countries.
For instance, the EEC has agreed to reduce their aggregate emissions by
8 percent from 1990 emissions levels.
[2] Kyoto Protocol, art. 2(2).
[3] This would also include those airports in non-EU countries
currently participating in the EU ETS--Norway, Iceland, and
Liechtenstein. See appendix I for further explanation of the EU ETS.
[4] Fuel consumption of U.S.-based airlines roughly doubled during that
same period.
[5] However, some aircraft available in the 1950s were about equally as
fuel efficient as jets currently available today.
[6] According to IPCC, adaptation is an adjustment that occurs in
response to expected or actual climatic stimuli or effects in order to
moderate damages or exploit beneficial opportunities.
[7] IPCC defines mitigation as technological change and substitution
that reduce resource inputs, such as energy use, and emissions per unit
of output. Although several social, economic, and technological
policies would produce an emissions reduction, with respect to climate
change, mitigation means implementing policies to reduce greenhouse gas
emissions.
[8] The PARTNER program--the Partnership for AiR Transportation Noise
and Emissions Reduction--is a cooperative research organization
sponsored by FAA, NASA, and Transport Canada, with members including
universities and other organizations with expertise.
[9] NextGen is a new, satellite-based air traffic management system
that is expected to increase the safety and enhance the capacity of the
air transport system. NextGen will transform the current radar-based
air traffic control system.
[10] 42 U.S.C. § 7571.
[11] However, EPA has the authority to set emissions standards. As the
technical agency with responsibility for international civil aviation
in the United States, FAA, in consultation with EPA, works with
representatives of other ICAO member countries to formulate the
standards.
[12] In addition, H.R. 2454, the American Clean Energy and Security Act
of 2009, § 221(b), 111th Cong. (2009), would require EPA to issue
standards for greenhouse gas emissions from new aircraft and new
engines used in aircraft by Dec. 31, 2012.
[13] In addition, in 2007, the Supreme Court ruled that greenhouse
gases meet the Clean Air Act's definition of an air pollutant and that
EPA has the statutory authority to regulate greenhouse gas emissions
from new motor vehicles under the Act. Massachusetts v. Environmental
Protection Agency, 549 U.S. 497 (2007). As a result of the opinion, EPA
must take one of three actions: 1) issue a finding that greenhouse gas
emissions cause or contribute to air pollution that may endanger public
heath or welfare; 2) issue a finding that greenhouse gases do not
endanger public health or welfare; or 3) provide a reasonable
explanation as to why it cannot or will not exercise its discretion to
issue a finding. In response to this case, EPA issued an Advance Notice
of Proposed Rulemaking, "Regulating Greenhouse Gas Emissions Under the
Clean Air Act," 73 Fed. Reg. 44354 (July 30, 2008). EPA subsequently
issued a proposed finding that carbon dioxide, methane, nitrous oxide,
and hydrofluorocarbon emissions from new motor vehicles are
contributing to air pollution which is endangering public health and
welfare. 74 Fed. Reg. 18886 (Apr. 24, 2009). EPA is moving forward with
the proposed finding while it develops proposed standards for
regulating greenhouse gas emissions from motor vehicles.
[14] To date, 192 countries have ratified the UNFCCC.
[15] The emissions reduction goal varies by country and is generally
higher for more highly developed countries. Some European countries,
for example, agreed to reduce emissions by 8 percent compared to 1990
levels.
[16] In addition to the current 27 EU member states, other European
countries not part of the EU, such as Norway, Iceland, and
Liechtenstein, participate in the ETS. These airports are included in
the amended ETS.
[17] Radiative forcing is a measure for the change of the Earth's
energy balance due to a change in concentrations of greenhouse gases
and other emissions that contribute to climate change.
[18] According to IPCC, the report was compiled by 107 lead authors
from 18 countries. Successive drafts of the report were circulated for
review by experts, followed by review of governments and experts. Over
100 contributing authors submitted draft text and information to the
lead authors and over 150 reviewers submitted suggestions for
improvement during the review process.
[19] According to IPCC, global aviation's global carbon dioxide
emissions totaled an estimated 480 million tons in 2000.
[20] According to EPA, in 2007 commercial aviation represented about 82
percent of all aviation emissions, and about 2.5 percent of U.S. carbon
dioxide emissions. In the United States, military aviation represents
less than 10 percent of total aviation emissions.
[21] EPA, Draft Inventory of U.S. Greenhouse Gas Emissions and Sinks:
1990-2007, (March 2009). The aviation estimates do not include fuel
consumed for international air transport per UNFCCC's reporting
guidelines; according to the EPA, in 2006, when those international
fuels were included, domestic and international commercial, military,
and general aviation flights represented about 3.4 percent of U.S.
carbon dioxide emissions.
[22] In the United States according to EPA, carbon dioxide emissions
from fossil fuel combustion in the transportation sector account for an
estimated 31 percent of carbon dioxide emissions (in carbon dioxide
equivalents not including fuels used for international flights). Carbon
dioxide equivalents provide a common standard for measuring the warming
potential of different greenhouse gases and are calculated by
multiplying the emissions of the non-carbon-dioxide gas by its global
warming potential, a factor that measures its heat-trapping ability
relative to that of carbon dioxide.
[23] This 3 percent radiative forcing estimate for aviation is based on
more recent research, included in IPCC's 2007 Fourth Assessment Report.
Originally, IPCC calculated a 3.5 percent estimate for 1992, which it
published in its 1999 special report, Aviation and the Global
Atmosphere.
[24] See Aviation Climate Change Research Initiative: A Report on the
Way Forward, (2008) citing Forster, P., et al. (2007), Changes in
atmospheric constituents and in radiative forcing. In: IPCC, 2007:
Climate Change 2007: The Physical Science Basis. Contribution of
Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M.
Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and New
York, NY, USA; and Sausen, R. et al., Aviation radiative forcing in
2000: An update on IPCC (1999), Meteorologische Zeitschrift, 14-4, 555-
561, 2005.
[25] The 1999 IPCC report originally estimated that aviation's impact
could be two to four times that of carbon dioxide alone. The use of a
radiative forcing ratio of the forcing of all aviation emissions over
carbon dioxide is an approximation and is an area for further research
and understanding.
[26] IPCC assumed a maturing global market with the above economic
growth rates from 1990 to 2025 and slightly lower economic growth rates
thereafter.
[27] This 5 percent estimate of aviation's contribution to 2050 global
radiative forcing is based on IPCC's midrange estimate. IPCC did not
provide this estimate for the 2050 high-and low-range scenarios.
[28] B. Owen and D.S. Lee, Allocation of International Aviation
Emissions from Scheduled Air Traffic--Future Cases, 2005 to 2050,
Manchester Metropolitan University (Manchester, UK, March 2006) and
Ralf Berghof, Alf Schmitt et al., CONSAVE 2050 Final Technical Report
(July 2005).
[29] The 1999 IPCC report included a high-growth emissions scenario for
2050 from an environmental organization that showed aviation
contributing 9.8 percent of global carbon dioxide emissions. This
estimate assumed air traffic levels for 2050 that were more than double
those used in the highest IPCC estimate. IPCC concluded that such an
estimate for 2050, though not impossible, was unlikely because it would
require countries to build more than 1,300 new airports with 15 gates
each, or the equivalent of 2 new airports per month for 60 years, which
would be unprecedented compared with historical increases in global
airport capacity.
[30] This estimate is based on emissions of carbon dioxide and nitrogen
oxides. In terms of fuel consumption, FAA estimates a 28 percent
increase in US carriers commercial aviation jet fuel from 2001 to 2025
(see FAA Aerospace Forecast, Fiscal Years 2009-2025, table 22).
[31] Two main methods, market exchange rates and purchasing power
parity are used to convert the GDP of a country in national currency
terms to a common currency, usually the U.S. dollar. GDP growth rates
can differ depending on the conversion method used.
[32] However, the forecast doesn't account for the possibility that
some airlines might adopt low-carbon alternative fuels.
[33] The United States is currently working on its future air traffic
management system, NextGen, as is Europe through the Single European
Sky Air Traffic Management Research Program (SESAR).
[34] Other studies have estimated aviation's share of current climate
change emissions and find aviation's contributions to climate change to
be larger when the impact of cirrus clouds is included. For example,
one environmental organization in a 2006 report included the upper
range for aviation-induced cirrus clouds' radiative forcing (from
Sausen et al, 2005, which was reported in IPCC) in its aviation
radiative forcing total and calculated that aviation contributed 9
percent of total radiative forcing due to human activity worldwide in
2000.
[35] Joosung J. Lee, Stephen P. Lukachko, Ian A. Waitz, and Andreas
Schafer, "Historical and Future Trends in Aircraft Performance, Cost,
and Emissions," Annual Reviews on Energy and Environment, vol. 26
(2001).
[36] The higher the bypass ratio, the more air bypasses the engine,
providing extra propulsion for the engine fan blades and increasing the
engine's efficiency.
[37] In addition, General Electric is developing a new fuel-efficient
engine, the GEnx. According to General Electric, this engine will
improve fuel burn by 15 percent, while also reducing NOx emissions,
compared with General Electric's previous generation of engine
technologies.
[38] The U.S. Air Force also is conducting research into more fuel
efficient engines through its ADVENT program, a joint effort with
engine manufacturers that Air Force officials told us is expected to
have commercial applications.
[39] However, National Aeronautics and Space Administration staff told
us that no such investments will be necessary.
[40] For more information on challenges in NextGen implementation see
GAO, Next Generation Air Transportation System: Issues Associated with
Midterm Implementation of Capabilities and Full System Transformation,
[hyperlink, http://www.gao.gov/products/GAO-09-481T] (Washington, D.C.:
Mar. 25, 2009).
[41] Although plants converted into biofuels remove carbon dioxide from
the air during growth, the biofuel production process is not emissions-
free. For instance, nitrous oxide--a powerful greenhouse gas--may be
emitted when nitrogen-based fertilizers are applied to soils to
increase yields of important biofuel feedstocks such as corn. In
addition, fossil fuels are burned during the harvesting, transporting
and refining of biofuel feedstock plants. Finally, researchers have
raised concerns that increased biofuel production could result in
additional greenhouse gas impacts due to the conversion of lands not
previously used for biofuel crop production.
[42] On May 26, 2009, EPA issued a Notice of Proposed Rulemaking
regarding the renewable fuel standard, as required by the Energy
Independence and Security Act of 2007 (EISA). When finalized, the
proposed rule would implement EISA's changes to the renewable fuel
standard. 74 Fed. Reg. 24904 (May 26, 2009).
[43] In addition, FAA and the U.S. Air Force, through the Partnership
for AiR Transportation Noise and Emissions Reduction (PARTNER) program-
-an FAA-NASA-Transport Canada-sponsored Center of Excellence, is
sponsoring a project that aims to develop a tool that can estimate the
life-cycle environmental impact from alternative jet fuels. The U.S.
Air Force is leading an interagency working group including EPA, FAA,
the Department of Energy and researchers to develop a document of life-
cycle analysis best practices.
[44] While in 2008 Boeing conducted a test flight of a small aircraft
powered by hydrogen fuel cells, the manufacturer indicated it does not
expect that large aircraft will be able to derive their primary energy
from such sources.
[45] For a discussion of biofuel production see GAO, Biofuels: DOE
Lacks a Strategic Approach to Coordinate Increasing Production with
Infrastructure Development and Vehicle Needs [hyperlink,
http://www.gao.gov/products/GAO-07-713] (Washington, D.C.: June 8,
2007).
[46] However, according to DOT, it could also be argued that because
aircraft do not face the potential for non-liquid fuel sources of
energy--for example, electricity--and because there is a proportionally
higher premium for refining jet fuel, aviation may be a more certain
consumer of biofuel supplies.
[47] Algae-based biofuel composed only 2.5 percent of the fuel blend.
[48] This analysis assumed that biofuels are first available in 2015
and their usage increases at a rate of 2 percent per year, and through
life-cycle carbon emissions, biofuels emit 20 percent the carbon
dioxide as jet fuel. For blended-wing body aircraft, the analysis
assumed an 18 percent fuel burn reduction and introduction of the
aircraft into global fleets in 2025 with a 30-year time frame to
achieve a penetration of 33 percent of global aircraft fleets. The
analysis also assumed the adoption of other improvements, including the
use of lightweight materials, open rotor engines, formation flying, and
multistage long-distance travel. We did not review the reliability of
this analysis.
[49] A lower assumed traffic growth rate would have reduced the study's
forecast of emissions. With respect to biofuels, this study assumed
that biofuels would be used between 2010 and 2050 (at which time they
would represent 25 percent of aviation fuels) and would produce 10
percent of the carbon dioxide emissions of fossil fuels. We did not
review the reliability of this analysis.
[50] For a comprehensive discussion of the economics of policy options
to address climate change as well as discussion of a combination of
such options, see GAO, Climate Change: Expert Opinion on the Economics
of Policy Options to Address Climate Change, [hyperlink,
http://www.gao.gov/products/GAO-08-605] (Washington, D.C.: May 9,
2008).
[51] However, to the extent that a cap-and-trade program regulates
other transportation sectors as well, costs of using alternative
transportation modes are likely to be higher as well.
[52] For example, the demand for energy may increase during
unexpectedly hot or cold periods, leading to price spikes and making it
more expensive for sources to meet the cap.
[53] The safety valve would help prevent the price of allowances from
exceeding the expected benefits of the emissions reductions. Under a
cap-and-trade program, the emissions cap could be set at a level that
balances the expected marginal cost of meeting the cap with an estimate
of the marginal benefits. The safety valve price could be set just
above the expected marginal costs to avoid the possibility that the cap
is overly stringent.
[54] We have reported on the importance of setting an emissions
baseline. For example, setting a baseline with poor historical data
could lead to the creation of a baseline that is above actual
emissions, leading to no emission reductions. See GAO, Climate Change
Science: High Quality Greenhouse Gas Emissions Data Are a Cornerstone
of Programs to Address Climate Change, [hyperlink,
http://www.gao.gov/products/GAO-09-423T] (Washington, D.C.: Feb. 24,
2009).
[55] However, some interest groups have expressed concern that an
emissions cap does not take into account emissions reductions that
airlines have achieved in recent years and claim that it unfairly
penalizes those airlines that have reduced emissions.
[56] For example, Association of European Airlines expressed a concern
that because some countries in Europe have taxes on aircraft carbon
dioxide emissions, airlines may be subject to those taxes as well as
the ETS, meaning that their emissions would be counted twice by two
different regulations.
[57] We have reported on lessons learned from the EU ETS. See GAO,
International Climate Change Programs: Lessons Learned from the
European Union's Emissions Trading Scheme and the Kyoto Protocol's
Clean Development Mechanism, [hyperlink,
http://www.gao.gov/products/GAO-09-151] (Washington, D.C.: Nov. 18,
2008).
[58] With respect to aircraft, the ETS currently regulates only carbon
dioxide emissions. However, according to the European Commission, it
has agreed to address nitrogen oxide emissions from aircraft through a
separate legislative measure. As of May 2009, no EU legislative
proposal has specifically addressed nitrogen oxide emissions from
aircraft.
[59] For example, Japan is considering creating a voluntary cap-and-
trade program and Japan Airlines already has indicated that it will
participate in the scheme, but only based on its domestic flights.
[60] H.R. 1862, 111th Cong. (2009).
[61] S. 3036, 110th Cong. (2008).
[62] For example, the social cost of carbon reflects the present value
of economic damages caused by an additional quantity of emissions.
Under an economically optimal policy, the price would be set at a point
where the marginal damages from global warming equal the marginal cost
of controlling emissions.
[63] A metric ton equals 2,205 pounds.
[64] The extent to which a cap-and-trade program would provide greater
certainty about emissions reductions depends on the design of the
particular program. For example, some programs may include cost
containment measures that allow total emissions to exceed the cap under
certain conditions.
[65] Price elasticity of demand is a measure of the responsiveness in
quantity demanded as a result of a change in price. Goods and services
with a high elasticity of demand will see larger changes in the
quantity demanded than the change in price.
[66] Equivalent to about $4.5 billion based on exchange rates on Apr.
20, 2009.
[67] According to industry interests groups we met with, to the extent
that airlines incur the costs of a tax or for cap-and-trade allowances,
their resources for upgrading their fleets with more fuel-efficient
aircraft and for implementing other emissions-reduction measures will
be more limited.
[68] Equivalent to about $11.60 based on exchange rates on April 20,
2009.
[69] Some organizations we met believe that revenues collected through
the auctions of allowances should be used for climate change mitigation
and adaptation as well as to help fund low-emissions technologies.
[70] H.R. 2454, § 221(b), 111th Cong. (2009).
[71] Emissions standards typically do not equalize marginal costs
across sources, a basic condition for efficiency. In the case of
greenhouse gas emissions, emissions are uniformly mixed and abatement
costs vary widely across sources. These characteristics favor market-
based instruments, which can achieve significant cost savings by
encouraging low-cost sources to make the bulk of the emissions
reductions.
[72] According to FAA and EPA, existing aircraft engine standards do
not mandate specific technologies and are developed on the basis of
technological practicability.
[73] According to EPA, well designed standards could give aircraft
engine manufacturers the flexibility to make cost-effective reductions.
In addition, according to an official in EPA's Office of Air and
Radiation, with the projected increase in jet fuel consumption and
related emissions, addressing greenhouse gas emissions will require
consideration of technology measures and market-based measures.
However, under a market-based program such as cap-and-trade, emissions
caps set the total emissions level and sources would need to determine
how to accommodate business growth while complying with the cap. Such
an approach gives sources an incentive to innovate and search for low-
cost ways to reduce emissions.
[74] In addition, the U.S. Air Force conducts research that has
potential for applicability for commercial aviation. For example,
through the ADVENT program, the Air Force is researching fuel-efficient
engine technologies.
[75] NASA refers to the three generations of technologies as N+1, N+2,
and N+3.
[76] The plan also sets goals for future noise levels and nitrogen
oxide emissions.
[77] National Science and Technology Council, National Plan for
Aeronautics Research and Development and Related Infrastructure
(Washington, D.C., Jan. 18, 2008).
[78] GAO, Aviation and the Environment: FAA's and NASA's Research and
Development Plans for Noise Reduction Are Aligned, but the Prospects of
Achieving Noise Reduction Goals Are Uncertain, [hyperlink,
http://www.gao.gov/products/GAO-08-384] (Washington, D.C., Feb. 15,
2008).
[79] GAO, Aviation and the Environment: NextGen and Research and
Development Are Keys to Reducing Emissions and Their Impact on Health
and Climate, [hyperlink, http://www.gao.gov/products/GAO-08-706T]
(Washington, D.C., May 6, 2008).
[80] About $200 million to $267 million per year based on exchange
rates on Apr. 29, 2009.
[81] Equivalent to approximately $2.1 billion based on exchange rates
on Mar. 31, 2009.
[82] The European Commission initiates the legislative process by
drafting specific pieces of legislation and proposing them to the
Council of the European Union and European Parliament, who together
serve as the EU's legislative branch.
[83] Under the EU's co-decision procedure, the legislative procedure
for environmental and certain other types of laws, both the Council of
the European Union and European Parliament must approve legislation in
order to enact a law. Once both bodies approve identical texts of the
legislation, it must be published in the Official Journal of the
European Union. The law goes into force 20 days after publication.
Thereafter, each member state has 1 year to transpose the directive
into national law.
[84] Directive 2008/101/EC, 2009 O.J. (L 8) 3. The directive was
amended on Mar. 26, 2009.
[85] Some flights are excluded from the cap, including military
flights, flight operations for emergency purposes, such as
firefighting, as well as airlines with very limited operations. See
2008/101/EC, 2009 O.J. (L 8) 3, Annex I.
[86] For instance, a flight from Los Angeles to London will have to
surrender allowances for its travel in U.S. airspace, international
airspace, and U.K. airspace.
[87] Historical aviation emissions is defined as the mean average of
the annual emissions in calendar years 2004, 2005, and 2006. This will
be the baseline for emissions reductions. See Directive 2008/101/EC,
2009 O.J. (L8) 3, art. 3c.
[88] See Directive 2008/101/EC, art. 3(c) (establishing the cap). The
cap for subsequent trading periods can be adjusted by an amendment to
the directive. See also Proposal for a Directive COM(2008) 16
(extending the trading periods to 8 years from 5 years). Although both
the European Parliament and the European Council have signaled final
approval of the proposed directive, final, formal approval had not
occurred as of June 2, 2009.
[89] Three percent of the total quantity of allowances to be allocated
will be set aside in a special reserve for new aircraft operators or
aircraft operators with rapid growth. Eligible aircraft operators must
apply to their assigned member states to obtain free allowances from
the special reserve. The European Commission will determine how the
allowances in the special reserve will be distributed. Any unallocated
allowances will be auctioned.
[90] Aircraft operators will be assigned to the member state that
either: (1) issued its operating license or (2) has the greatest
estimated emissions from flights performed by that aircraft operator in
2006 or the operator's first year of operation. See Directive 2008/101/
EC, 2009 O.J. (L 8) 3, art. 18(a). These assignments were made in
February 2009 and most U.S. airlines were assigned to the United
Kingdom. According to the Directorate-General of the Environment (DG
Environment), the auctions will be open to anyone to participate and
the Commission is currently developing the regulation containing
detailed provisions for member state auctions.
[91] For 2012, each member state's total allowances will be based on
verified 2010 emissions. In subsequent years, the total allowances will
be based on verified emissions from 2 years prior.
[92] According to the 2008 directive, it shall be for member states to
determine the use to be made of revenues generated from the auctioning
of allowances. Those revenues should be used to tackle climate change
in the EU and third countries, inter alia; to reduce greenhouse gas
emissions; to adapt to the impacts of climate change in the EU and
third countries, especially developing countries; to fund research and
development for mitigation and adaptation, including in particular in
the fields of aeronautics and air transport; to reduce emissions
through low-emission transport; and to cover the cost of administering
the Community scheme.
[93] Alternatively, if an aircraft operator has excess emissions
allowances, it will be able to sell those excess allowances on the
market.
[94] The European Commission will determine the exact percentage of
CERs and ERUs that aircraft operators can use in the 2013 through 2020
trading period. In determining the percentage of CERs and ERUs that
each covered sector can use in the 2012 through 2020 trading period,
the Commission will ensure that overall CER and ERU usage does not
exceed 50 percent of the emissions reductions achieved in Phase II
(2007 through 2012), measured from a baseline of 2005 emissions levels.
[95] According to the DG Environment, draft legislation and a number of
bills proposed in the 110th Congress would have triggered such
consideration. See McCain-Lieberman, S. 280, 110th Cong. (2007);
Lieberman-Warner, S. 2191, 110th Cong. (2007); Dingell-Boucher, draft
bill; and Waxman-Markey, H.R. 1590, 110th Cong. (2007), H.R. 6186,
110th Cong. (2008).
[96] On Feb. 11, 2009, the Commission adopted the Preliminary List of
Aircraft Operators and their administering Member States, Commission
Notice Pursuant to Article 18a(3)(a) of Directive 2003/87/EC, C(2009)
866. Additional preparations have included holding a number of
stakeholder workshops to discuss implementing this directive and
development of guidelines for monitoring, reporting, and verification
of emissions, according to the DG Environment.
[97] All operators must submit their monitoring plan by the end of
August 2009, according to the DG Environment.
[98] United Nations Framework Convention on Climate Change, 1992,
Article 2, GE.05-62220. (E) 200705.
[99] Id. at Article 4(1)(b).
[100] Id. at Article 4.
[101] Kyoto Protocol to the United Nations Framework Convention on
Climate Change, 1999 [hereinafter Kyoto Protocol].
[102] The Kyoto Protocol recognized that industrialized nations are the
largest contributors to greenhouse gas emissions and therefore divided
the signatory countries into two groups--Annex I countries that are
industrialized nations subject to binding targets, either emission
reduction or limitation requirements, and Non-Annex I countries that
are not subject to binding targets.
[103] Kyoto Protocol, supra note 20, art. 3(1).
[104] Id. at art. 2(2).
[105] Convention on International Civil Aviation, Dec. 7, 1944, Ninth
ed., 2006, 61 Stat. 1180, 15 U.N.T.S. 295 [hereinafter Chicago
Convention].
[106] See Id. at art. 1.
[108] Article 11 provides that "Subject to the provisions of this
Convention, the laws and regulations of a contracting State relating to
the admission to or departure from its territory of aircraft engaged in
international navigation...shall be applied to the aircraft of all
contracting States without distinction as to nationality, and shall be
complied with by such aircraft upon entering or departing from or while
within the territory of that State."
[109] Article 12 states that "[e]ach contracting State undertakes to
adopt measures to insure that every aircraft flying over or maneuvering
within its territory and that every aircraft carrying its nationality
mark, wherever such aircraft may be, shall comply with the rules and
regulations relating to the flight and maneuver of aircraft there in
force....Over the high seas, the rules in force shall be those
established under this Convention,..."
[109] Article 15 provides in part that "no fees, dues or other charges
shall be imposed by any contracting State in respect solely of the
right of transit over or entry into or exit from its territory of any
aircraft of a contracting State or persons or property thereon."
Moreover, charges that may be imposed must be non-discriminatory.
[110] Article 24 covers customs and related duties for aircraft of
contracting states and includes the provision that "fuel...on board an
aircraft of a contracting State, on arrival in the territory of another
contracting State and retained on board on leaving the territory of
that State shall be exempt from customs duty, inspection fees or
similar national or local duties and charges."
[111] Consolidated Statement on Continuing ICAO Policies and Practices
Related to Environmental Protection, ICAO Res. A36-22, 36th Session,
Appendix L, 1(b)(1)(2007) [hereinafter ICAO Res. A36-22].
[112] Many positions referred to in this article cite to ICAO
Resolution A35-5 rather than the A36-22.
[113] ICAO Res. A36-22, supra note 30, Appendix K.
[114] This also is referred to as the U.S.-EU Open Skies Agreement.
[114] See generally Id.
[114] Id. at art. 12, 3.
[116] Bali Action Plan, Decision 1/CP.13, 1 (FCCC/CP/2007/6/Add.1).
[117] Letter of U.S. Ambassador Kristen Silverberg to Jos Delbeke,
Acting Director General General, Environment Directorate General, Oct.
30, 2008; and letter from the Ambassadors of Australia, Canada, China,
Japan, Korea and the United States to Ambassador Peter Witt of Germany,
Apr. 6, 2007 [hereinafter Ambassador Letter].
[118] See statement of Secretary Clinton: "President Obama and I
recognize that the solutions to this crisis are both domestic and
global, that all nations bear responsibility and all nations must work
together to find solutions." See also statement of Special Envoy Stern:
"Yet we can only meet the climate challenge with a response that is
genuinely global. Eighty percent of greenhouse gas emissions are
produced outside the United States, and a rapidly growing percentage is
produced in emerging market countries."
[119] ATA's analysis is contained in a non-public Legal Analysis
Summary provided to GAO.
[120] Chicago Convention, supra note 24, art. 11.
[121] Id. at art. 15.
[122] Article 24 provides that "fuel...on board an aircraft of a
contracting State, on arrival in the territory of another...shall be
exempt from customs duty, inspection fees or similar national or local
duties and charges."
[123] Chicago Convention, supra note 24, art. 1. Article 1 provides
that every contracting state has "complete and exclusive sovereignty
over the airspace above its territory."
[124] Id. at art. 12.
[125] Id. at art. 15.
[126] See Josh Voorhees, Greenwire, EU brings airlines into climate
scheme; industry vows court fight (2008), at [hyperlink,
http://www.eenews.net/Greenwire/2008/07/08/archive/3].
[127] Press Release, Air Transport Association Chief Executive Says
European Aviation Emissions Trading Scheme 'Contrary to International
Law and Bad Policy' (Oct. 30, 2008), available at [hyperlink,
http://www.airlines.org/news/releases/2008/news_10-30-08.htm].
[128] A "Sense of the Congress" is not legally binding if passed.
[129] H.R. 915, Sec. 514(1), 111th Cong. (2009).
[130] Id. at Sec. 514(2).
[131] The legal assessment was conducted by an independent contractor
for the DG Environment.
[132] IETA, IETA's position on the Inclusion of Aviation in the EU ETS,
available at [hyperlink,
http://www.ieta.org/ieta/www/pages/getfile.php?docID=2413].
[133] Id. at 2.
[134] Id.
[135] The legal assessment was conducted by an independent contractor
for the DG Environment.
[136] Giving Wings to Emissions Trading, Inclusion of Aviation under
the European emissions trading system (ETS): Design and Impacts (The
Delft Report), Report to the European Commission, DG Environment,
No.ENV.C.2./ETU/2004/0074r, July 2005 [hereinafter Delft Report]. This
report was prepared for and endorsed by the European Commission.
[137] Id. at 170-73.
[138] Chicago Convention, supra note 24, art. 11.
[139] Article 12 requires contracting states to ensure that aircraft
under their jurisdiction are in compliance with rules and regulations
relating to the flight and maneuver of aircraft.
[140] Chicago Convention, supra note 24, art. 15.
[141] Id. at art. 24.
[142] The Delft Report at 175-77.
[143] Id. at 176-77
[144] Id. at 177.
[145] Consolidated statement of continuing ICAO policies and practices
related to environmental protection, ICAO Res. A35-5, 35th Session,
Appendix 1 (2004) [hereinafter ICAO Res. A35-5]. "ICAO endorses an open
emission system for international aviation" and requests council focus
on two areas under this framework.
[146] The Delft Report further elaborates: "the operation of an ETS
does not unilaterally limit the volume of traffic — or aircraft types,
as it only provides incentives to reduce emissions over time; fair and
equal opportunity to participate in the ETS is already covered under
the Chicago Convention's non-discrimination clause and this must be
adhered to under the ETS." See pp. 179-181.
[147] Letter to the German Presidency regarding Commission proposal to
extend ETS to aviation (Apr. 6, 2007).
[148] Id.
[149] Id.
[150] Id.
[151] Id.
[152] For brevity's sake, we have not included explanatory articles
because they are repetitive of what is contained in this appendix. Here
we highlight those articles which set forth legal positions on the
issue.
[153] Daniel B. Reagan, Putting International Aviation Into the
European Union Emissions Trading Scheme: Can Europe Do It Flying Solo?,
35 B.C. Envtl. Aff. L. Rev. 349 (2008).
[154] Id. at 380-81.
[155] Id. at 381-82.
[156] Id. at 382.
[157] Id. at 383.
[158] Gisbert Schwarze, Including Aviation into the European Union
Emissions Trading Scheme, European Environmental Law Review (2007).
[159] Id. at 12-15.
[160] Id. at 12-13.
[161] Id. at 13-14.
[162] In the alternative, as argued, even if this did constitute a
charge, Article 15's only applicability is to discrimination as to
nationality. Id.
[163] Gisbert Schwarze, Including Aviation into the European Union
Emissions Trading Scheme, p. 13-14, European Environmental Law Review
(2007).
[164] Id. at 14.
[165] Id.
[166] Id.
[167] Id.
[168] United Nations Framework Convention on Climate Change, supra note
17, art. 4(2)(a).
[169] Kyoto Protocol, supra note 20, art. 2(2).
[170] Schwarze at 13. See also ICAO Res. A35-5, supra note 66, Appendix
I Nr. 2(c)(1).
[171] See Voorhees, supra note 46.
[172] See Ambassadors Letter, supra note 37.
[173] Chicago Convention, supra note 24, art. 84. The Council is
composed of 36 contracting states elected by the Assembly. See Id. at
art. 50. When a disagreement is submitted to the Council, the Council
will invoke the Rules of the Settlement of Differences, established in
1957, which sets forth procedures for disputes.
[174] Id. at art. 84. Additional requirements for settlement of
disputes and penalties are contained in Articles 85, 86, 87 and 88 of
the Chicago Convention. Alternatively, a challenge could potentially be
brought against a carrier. If a carrier chooses to move forward and not
comply with the ETS, action could be brought under the Chicago
Convention Article 87 and force the airline to cease operations over
any contracting state.
[175] See U.S.-EU Air Transport Agreement, art. 19.
[176] See Id. at art. 19(7).
[177] See Aimee Turner, Flight Global, EU warns ICAO it will go it
alone if no progress is made with ETS (2007), available at [hyperlink,
http://www.flightglobal.com].
[178] Id.
[179] See Appendix II for a list of the experts we interviewed.
[180] We did not provide specific definitions for "low," "medium," and
"high" and let each respondent determine what it meant to them.
[181] See appendix III for a copy of the assessment tool that we asked
the experts to complete as well as complete results. Additionally, we
asked the experts to describe the major challenges to the widespread
use of the options and the actions that the U.S. federal government
could take to promote the development and/or adoption of any of these
options.
[182] For alternative fuel options, we used a four-point scale to
assess each option's potential to reduce carbon dioxide emissions ("no
potential," "low potential," "medium potential "or "high potential").
[183] We defined "approximately the same number of experts" as being
either the exact same number of experts or as one fewer or one more
expert.
[End of section]
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