Reducing aviation's climate impact

Environmental Defense Fund has been working on solutions to address international aviation’s environmental impacts for more than two decades.

EDF’s approach to international aviation involves market-based measures, stronger efficiency improvements and alternative fuels. If done correctly, these approaches can reduce the sector's pollution levels.

Global aviation emissions pact

The global market-based measure adopted in October 2016 by the countries of the International Civil Aviation Organization will limit the net carbon emissions of international flights between participating countries for the years 2021-2035. The limit is initially set at the average of 2019-2020 levels. Provisions in the Carbon Offsetting and Reduction Scheme for International Aviation, or CORSIA, require evaluation of it every three years in view of the goals of the Paris climate agreement, offering the possibility of tightening the limit in the future. Separately, ICAO is conducting a review of aviation emissions in light of the Paris agreement.

If fully implemented, CORSIA could be a significant step forward for global climate action. It could prevent nearly 2.5 billion tonnes of CO2 emissions into the atmosphere over the first 15 years of the program – more if ambition is increased by tightening the limit.

CORSIA affords airlines flexibility to choose how to cut CO2. They can:

  • Fly more efficient aircraft.
  • Use new technologies to set more efficient flightpaths and reduce delays.
  • Use sustainable lower-carbon alternative fuels.
  • Invest in emissions offsets within or outside of the aviation sector.

The program covers all flights between participating countries for the years 2021-2035. As of Aug. 29, 2019, 81 nations have signaled their intent to participate in a first voluntary phase from 2021-2026, with participation being mandatory for all but the least emitting states for the years 2027-2035. Taking into account the reservations filed by a few countries, our estimates indicate that the expected participation will cover about 77 percent of anticipated emissions growth between 2021 and 2035 – more if more states join up. ICAO is working with governments and organizations to provide capacity-building support to help nations participate in the program. EDF continues to engage in the development of CORSIA to ensure robust rules for accountability and environmental integrity, including to prevent double counting of emissions offsets used by airlines.

Efficiency improvements

While the efficiency of aircraft—like that of cars—improved greatly in past decades, some analyses indicate that trend has generally stalled since 2012 in the United States. EDF supports strong aviation CO2 standards in the U.S. and through ICAO. As a first step, the U.S. needs to implement the new CO2 standard adopted by ICAO in 2016 – a standard supported by the aviation sector, but which falls short of what is needed to address climate change effectively. The U.S. should work to strengthen that standard and apply it to our domestic flights and to flights all over the world.

In 2016, the Environmental Protection Agency concluded that CO2 from aviation contributes to pollution that endangers public health and welfare. This finding creates a legal requirement for the EPA to establish a CO2 emissions standard for aircraft. In the past, the agency has set aviation emissions standards, which are enforced by the Federal Aviation Administration, at the levels suggested by ICAO. The EPA’s aviation endangerment finding has been targeted for attack, but the comprehensive scientific analysis supporting this finding make revisions that weaken or backtrack from this endangerment finding very unlikely to survive judicial review.

Alternative fuels

Airlines are promoting various alternative fuels, including biofuels, as key to the future of carbon-neutral growth in ICAO. Some biofuels do show promise, but without strict standards, including on avoiding double counting, aviation's thirst could destroy forests to make way for jet-fuel plantations. That would make global warming worse and hurt the people whose lives depend on the forests.

EDF is fighting for proper carbon accounting of biofuel-related emissions, and incentives to make trees worth more alive than dead.

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