Initially included as part of the Kyoto Protocol, oversight
of international aviation emissions got punted in the 1990s to the International Civil Aviation Organization, which has sat on the issue for two decades and continues to be the chosen overseer.
Although ICAO's 192 member states had long agreed to technology, operations and infrastructure measures to help address GHG emissions from international aviation, negotiations over a market - based measure (MBM) stalled for several years, leading to efforts by multiple countries to implement their own regulations or taxes
on international aviation emissions.
A new study by Oeko - Institut analyses for the first time potential carbon offset supply for a global market - based mechanism
for international aviation emissions to be adopted in 2016.
Despite their magnitude,
international aviation emissions are largely unregulated.
Currently 73 states representing over 88 percent of
international aviation emissions have agreed to participate in the voluntary phases of the ICAO Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) from 2020 through 2026, including the U.S. and China.