Governments at the International Civil Aviation Organization—the international body that oversees civil aviation—have agreed to reduce greenhouse gas emissions from aircraft. This is the first time governments have reached an agreement on actions to reduce emission from a specific economic sector. The deal stands in stark contrast to the failure of the International Maritime Organization (IMO)—a similar group that oversees international shipping—to reach agreement on limiting greenhouse gas pollution from large commercial ships last week.

Although the agreement is noteworthy, the details are disappointing. Governments and industry agreed to cap greenhouse gas emissions from international aviation at 2020 levels, and to improve fuel efficiency by 2 percent annually to 2050. Given likely advances in bio fuels, satellite-based navigation, and aircraft design, a cap at 2020 emissions levels essentially locks in business as usual and allows another decade of increasing emissions. The participating governments will also aim to set a global CO2 standard for aircraft engines in 2013.

The aviation agreement affirms the European Union’s inclusion of aviation emissions into their Emissions Trading Scheme and paves the way for similar action from other nations.

This will make it more difficult for US airlines to argue for an exemption to the European regulations, which go into force in 2012. A group of US airlines filed suit in a British court in December objecting to the European rules. Earthjustice has intervened in support of the right of nations to take independent action to reduce greenhouse gas emissions when the international community has failed to act. The case has since been transferred to the European Court of Justice.

The international aviation agreement also bolsters claims brought by Earthjustice in US federal court on behalf of a coalition of US environmental groups. That suit challenges EPA’s unreasonable delay in exercising its authority to regulate climate pollution from ships and aircraft under the Clean Air Act.

“Europe is showing admirable leadership by bringing aviation into its comprehensive plan to reduce greenhouse gas emissions,” said Earthjustice attorney Sarah Burt. “This reinforces our belief that strong domestic action can spur progress on the international front. It is now time for the US to step up to the plate and support them with similar action.”