Aviation’s Total Climate Impact

FACT SHEET

It’s about more than just CO2

Aviation must reduce its total impact on climate

For a long time, the aviation industry and governments have ignored the fact that it’s not only about CO2: burning kerosene at altitude also generates contrails, induced cloudiness and NOx derivatives that, although short lived, contribute substantially to global heating. This has led to a public perception of air travel being a relatively small problem, and to a lack of effective mitigation of the industry’s climate impact.

Now is the time to address the total climate impact of aviation!

 

This fact sheet explains the scientific state of the art concerning non-CO2 impacts of air travel, including the most recent paper in Atmospheric Environment by 21 scientists prominent in the field published in September 2020. 

THE FACTS:

1. Total aviation-caused climate heating is 3 times that of CO2 alone. On average, a flight’s CO2 impact must be therefore tripled to account for its total climate impact.

2. Currently (2018), from oil well through flights, aviation accounts for 5.9% of all human-induced climate heating, when including non-CO2 impacts. CO2 emissions alone are 2.9%. These numbers are immense when considering that this impact is caused by a tiny part of the world population.

3. Cutting air traffic reduces non-CO2 climate impacts immediately, while CO2 will continue heating the atmosphere for hundreds of years – even if aviation was stopped right now. Reducing non-CO2 impacts is extremely worthwhile, because they are worse than CO2 for the climate, even though short-lived.

4. Technical and operational mitigation of the non-CO2 impacts of aviation is possible, e.g. through adapting flight trajectories. It is still being resisted, though.

WHAT NEEDS TO BE DONE:

1. Non-CO2 impacts have to be fully accounted for by the industry, by institutions and governmental bodies and by UNFCCC within the framework of the Paris Agreement.

2. Known measures to mitigate non-CO2 impacts, such as contrail avoidance and the adoption of lean-burn low NOx engines, must be pursued immediately in addition to CO2 mitigation.

3. Research and development of operational and technological improvements, which give the same importance to the reduction of non-CO2 impacts as to CO2 reduction, must be intensified and funded.

4. Air traffic must not be allowed to return to pre-Covid-levels. Accordingly, bailouts, subsidies, tax exemptions, and the construction and expansion of airports must cease. Governmental measures for a deep, sustained reduction of flights and for substituting alternatives like rail travel and renewably-powered ships must be quickly implemented.