All major United States airlines and most smaller air carriers have voluntarily committed to a climate-mitigation plan that's independent of the Paris Agreement, the Federal Aviation Administration reported last week.
"It’s a lot," said Dan Williams, the environmental protection specialist tasked with implementing the program for the FAA. "It’s more than 97 percent of the total for the international fuel use for operators, and therefore emissions."
FAA uses international fuel use as the metric for participation, rather than number of airlines, because the program comes from the International Civil Aviation Organization (ICAO), the UN group that establishes global rules and standards for air travel. Because of ICAO's global influence, said Nancy Young, vice president of environmental affairs for the trade group Airlines for America, most countries also meet its standards for domestic flights.
"They have jurisdiction over flights between countries in terms of those rules, although oftentimes their rules also get picked up on a domestic basis," Young said in a webinar hosted by the Center for Climate and Energy Solutions. "The application here applies to pretty much every significant aircraft operator whether they're a business jet or a commercial airline."
The participating U.S. air carriers (listed here) have all volunteered to participate, Williams said.
"Of the remaining 2-point-something percent that hasn’t volunteered, you’re talking sort of really small charter operators, sort of businesses that have private jets that they fly around, and some of them we assume probably aren’t aware that the program exists."
While voluntary now, the program is designed to become mandatory after 2027. Very small operators and very small planes are exempted from the scope, as are flights for medical emergencies, disaster responses, and other humanitarian purposes.
The program, called the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), caps emissions at 2020 levels even as air traffic is expected to triple by 2050. Airlines approaching the cap can gain headroom by using sustainable fuels or purchasing offsets through a carbon market.
Since Jan. 1 airlines have been monitoring and reporting their emissions. They will continue to do so in 2020, and ICAO will use that data to set the baseline cap.
A 2020 cap may prove insufficient for a world that needs to achieve net-zero emissions by 2050. But it could buy the airlines time to adopt more fuel-efficient aircraft and await carbon-neutral fuels. The benefits are good enough to get the Environmental Defense Fund on board.
"We're big fans of CORSIA," said Kelley Kizzier of EDF. "If successful it can limit emissions in this fast-growing sector and spur greater ambition in the aviation sector."
The plan could also catalyze a global carbon market, Kizzier said, which could provide enforcement for emission limits and move money from polluters to innovators. "As an environmental organization that's why we are interested in markets," EDF's Nat Keohane said at the Paris Climate Conference in 2015, "because we think they're critical to driving long-run ambition."
Because ICAO operates outside of the parameters of the Paris Agreement, the CORSIA program is unaffected by President Trump's planned withdrawal (While Trump has announced a withdrawal, the U.S. can't officially withdraw until November 2020, soon after the next election). Trump would find it even more difficult to remove the U.S. from ICAO.
ICAO sets uniform aviation standards that allow airlines to operate in 191 member countries without having to conform to 191 different sets of regulations. For this reason, the airlines themselves favor ICAO and CORSIA, Young said.
"Our position with the administration has been that we’re very pleased that they have authorized going forward with this program," Young said. "Our position has been this is an important thing for operating internationally."
