The EPA took a first step toward setting an emissions standard for commercial aircraft on Wednesday, pleasing the industry and disappointing environmental advocates who sought tougher rules.

In announcing the rule, EPA Administrator Andrew Wheeler said the agency was trying to match the 2016 rule set by the International Civil Aviation Organization, a U.N. office, to address global emissions from aircraft.

A leading industry lobby and trade group, Airlines for America, said it was pleased with the rule, which environmental groups criticized as feeble, pointing to the agency’s own admission that the proposal would likely not curb plane emissions.

The Trump administration offered the rule at a pivotal time for the industry, which has been burning through cash due to the coronavirus pandemic, as it faces technical challenges in flying in a hotter world, is bracing for rising sea levels due to human-caused climate change and generates a massive portion of greenhouse gases in the U.S. transportation sector and worldwide.

Major emitter

Aviation generates about 3 percent of global greenhouse emissions — meaning if it were a country, it would rank among the top 10 nations with the biggest carbon footprints, on par with nations like Germany, Italy and Japan.

The proposed standards would not apply to aircraft in use but instead cover planes in a series of steps and deadlines, depending on the type of plane, including a requirement for new designs certified as of January 2020. Other deadlines under the proposal would be met for different planes in 2023 and 2028.

“We are implementing the ICAO recommendations, ICAO standards,” Wheeler told reporters. “The finalized regulation will help ensure that older, less efficient airplanes are replaced by newer, more efficient models.”

Strikingly, in a draft version of the proposal, the EPA acknowledged that it is not expected to lower greenhouse gas emissions.

“The EPA is not projecting emission reductions associated with today’s proposed GHG regulations,” the agency said, citing the ICAO rule in 2016, which had already prompted manufacturers to respond.

Forced by environmentalists who sued the agency, the EPA acknowledged in 2016 that emissions from airplanes threaten the climate and humans — a finding that required the agency to set limits for plane emissions.

“The Trump administration is trying to dodge its legal responsibility and help airlines escape accountability for their dangerous emissions,” said Clare Lakewood, climate legal director at the Center for Biological Diversity, an environmental group. “As the climate crisis deepens, we desperately need technology-forcing standards that actually reduce aircraft pollution.”

Decarbonizing the aviation sector is difficult technologically and legally, as Democrats on the House Select Committee on the Climate Crisis said in a June report .

“Full electrification of airline fleets, if technologically feasible, may be decades off,” the committee said in the report, the result of 18 months of work. And because the industry is inherently international, it can be difficult to determine which country is responsible for what emissions.

“EPA’s proposal to adopt ICAO’s fuel efficiency and CO2 certification standard for newly manufactured aircraft is good for our industry, for our country and for the world,” Nancy Young, A4A Vice President, Environmental Affairs, said, while Boeing called the EPA proposal “a major step forward for protecting the environment and supporting sustainable growth of commercial aviation and the United States economy.”

Airport woes

As the world heats, sea levels are rising, prompting managers of airports, which are often on low-slung stretches of land near water, to prepare for rising water levels.

In 2017, Oakland and San Francisco sued BP PLC, Chevron Corp., ConocoPhillips Co., Exxon Mobil Corp. and Royal Dutch Shell PLC over climate change damages, calling for them to pay for the costs of building sea walls to rebuff rising waters.

Those cases are still in court while Oakland builds a seawall to ring its airport.

Another hurdle for a warming planet: Planes can’t fly when it gets too hot.

Dozens of flights in Phoenix were grounded in the summer of 2017 when temperatures soared to roughly 120 degrees Fahrenheit.