CORSIA - the UN’s plan for handling aviation emissions

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) was created with the aim of tackling CO2 emissions growth from international aviation using a system of offsets. CORSIA was agreed upon by the International Civil Aviation Organization (ICAO) during their 2016 Assembly, and it is the only global initiative which targets international aviation. Under Climate accords such as the Kyoto and Paris Agreements, individual countries are to set their own emissions reduction targets – these include domestic flights but exclude international aviation.

As part of CORSIA, airlines have been required to monitor CO2 emissions from international flights since 1 January 2019 in order to provide an emissions baseline at 2020 levels. The airlines will then be able to offset their carbon emissions above this level by investing in verified projects such as wind farms or tree planting initiatives, with the aim of creating carbon neutral growth beyond 2020 levels.

The first phase of the offset scheme will begin in 2021, although membership for this phase is not mandatory. So far, 78 countries have voluntarily signed up for the initial phase, covering over 76 percent of international aviation activity. Crucially, these do not include Brazil, China, India or Russia, which have huge populations and some of the world’s fastest growing aviation activity.

In the second phase, from 2027 to 2035, CORSIA will become mandatory for almost all airlines, with certain exceptions for tiny operators, those from the least developed countries, and those operating humanitarian and medical flights, for example. Domestic flights, which currently account for almost 40 percent of all aviation emissions, are exempt from the calculation. So, too, are most small private jets due to their size; although they have a relatively small impact overall, they are some of the worst polluters by far [paywall] when it comes to CO2 emissions per passenger mile.

Aeroplane taking off

The consensus from climate campaigners, and even from many governments, is that CORSIA is a flawed system which will fail to have any real impact on emissions. It is completely out of line with the Paris Agreement – or indeed, any other previously agreed climate targets. To stay below the Agreement’s ‘safe’ temperature rise of 1.5°C, the Intergovernmental Panel on Climate Change (IPCC) has warned that in 2030, global CO2 emissions need to be around 55 percent lower than 2017 levels. CORSIA, however, offsets emissions growth after 2020. Additionally, this could benefit countries which already have high emissions, while restricting emerging economies that are only just beginning to grow their aviation industries.

Experts have warned that ignoring emissions up to 2020 levels, exempting domestic flights, and the lack of engagement from large polluters such as India and Russia, will mean that in CORSIA’s first phase, just a quarter of the total emissions from aviation could be regulated by this scheme, allowing pollution to multiply in the meantime. Additionally, this is not a long term scheme; it is currently planned to run only until 2035. If it is not extended beyond this, as little as 6 percent of projected CO2 emissions from international aviation could be covered between 2015 and 2050.

Finally, CO2 is not aviation’s only contribution to the climate crisis. Aircraft also emit greenhouse gases such as aerosols and nitrogen oxides, which become particularly harmful at altitude, and these are not taken into account by CORSIA. The combined effect of these means the historic impact of aviation on the climate has been two to four times greater than that of CO2 alone, according to the IPCC.

Written by Vicki Brown