Press release

Proposed EPA CO2 standard lags new aircraft fuel efficiency by more than a decade

July 22, 2020 (Washington, D.C.) — Earlier today, the U.S. Environmental Protection Agency’s (EPA) Office of Transportation and Air Quality issued the proposed rule, Control of Air Pollution From Aircraft and Aircraft Engines: Proposed Greenhouse Gas (GHG) Emissions Standards and Test Procedures. This rule, when finalized, will represent the first time the United States has regulated carbon dioxide (CO2) emissions from aircraft. The standards will apply to all new aircraft starting in 2028.

Regrettably, not only is the proposed standard too weak to accelerate investment in more fuel-efficient aircraft and engines, it lags existing aircraft technologies by more than 10 years, according to a forthcoming ICCT report. This proposal cannot support the United States’ goal of carbon neutral growth for its aviation sector, let alone reduce the absolute contribution of flying to climate change.

Specifically, the average new aircraft today already meets the requirements in the proposed rule. “Our latest analysis suggests that the average new aircraft delivered in 2019 was already about 6% more fuel-efficient than EPA would require in 2028,” says Sola Zheng, lead author of the study. “The United States will need a more ambitious standard if it is to meet its goal of carbon neutral growth for its carriers starting this year.”

EPA’s standard closely follows the lead of the International Civil Aviation Organization (ICAO), which finalized an international aircraft CO2 standard in 2016. Remarkably, the average new aircraft delivered that year already met ICAO’s 2028 efficiency requirements (figure).

Figure 1

Moreover, the most advanced new aircraft delivered in recent years are ahead of the standard by 10%–20% on average. “In the closing months of President Trump’s first term, EPA is proposing an aircraft standard that would be obsolete the day it is finalized,” says Dan Rutherford, ICCT’s aviation program director. “This administration—or the next administration —should tighten the standard in a way that can support new markets for U.S. manufacturers.”

The EPA has an array of options it could choose from to make the final regulation more effective. It could, for example, apply the CO2 standard to in-service aircraft, rather than just new aircraft. This would create new markets for U.S. airframe (Boeing) and aircraft engine (GE, Pratt & Whitney) manufacturers by promoting the retirement of older, less efficient designs. Additionally, the use of flexibility mechanisms like averaging and banking would allow standards to be set based on the performance of the best aircraft rather than the worst. Such mechanisms could enable more ambitious, cost-effective reductions, and are already in place in similar standards for passenger cars and commercial trucks.

There is unrealized potential for manufacturers to develop more fuel-efficient aircraft designs. From 1960 to 2019, the average fuel burn of new aircraft fell by between 1.1 and 1.3% annually, depending on metric. However, our comprehensive technology assessment found that the fuel burn reduction of new aircraft could be accelerated up to 2.2% per year through 2034 via the adoption of cost-effective technologies.

This suggests that EPA should go back to the drawing board and strengthen this proposal to finalize more meaningful standards. International leadership, in the form of more stringent standards for new type designs at ICAO, is also needed.


Dan Rutherford,, +1 650 336 3536

Sola Zheng,