John Kerry, secretary of state of the United States, called the aviation deal "unprecedented." Olumuyiwa Benard Aliu, council president of the International Civil Aviation Organization, a United Nations body that will oversee the agreement, acknowledged negotiations had been tough, but added that almost all nations now had a "practical agreement and consensus on this issue."
Despite the backslapping, much still needs to be resolved before the 15-year aviation accord comes into force beginning in 2021. The first six years of the deal will be voluntary.
Carriers including Delta Air Lines and Air China are expected to eke out some climate change reductions by making their aircraft fleets more efficient and increasing their use of biofuels.
But most of the industry's focus will fall on a complicated offsetting system, in which airlines buy credits from climate change projects, like renewable energy programs often in the developing world, to counterbalance their own carbon emissions.
