Growth in aviation contributes more to global warming than is generally appreciated because of the mix of climate pollutants it generates. Here, we model the CO2 and non-CO2 effects like nitrogen oxide emissions and contrail formation to analyse aviation’s total warming footprint. Aviation contributed approximately 4% to observed human-induced global warming to date, despite being responsible for only 2.4% of global annual emissions of CO2. Aviation is projected to cause a total of about 0.1 °C of warming by 2050, half of it to date and the other half over the next three decades, should aviation’s pre-COVID growth resume. The industry would then contribute a 6%–17% share to the remaining 0.3 °C–0.8 °C to not exceed 1.5 °C–2 °C of global warming. Under this scenario, the reduction due to COVID-19 to date is small and is projected to only delay aviation’s warming contribution by about five years. But the leveraging impact of growth also represents an opportunity: aviation’s contribution to further warming would be immediately halted by either a sustained annual 2.5% decrease in air traffic under the existing fuel mix, or a transition to a 90% carbon-neutral fuel mix by 2050.
Quantifying aviation’s contribution to global warming
Publication details
Theme(s)
The urgency of zero
The urgency of zero
Type(s)
Research paper
Research paper
Author(s)
Allen, Myles
Allen, Myles
Year(s)
2021
2021
Environmental Research Letters
Latest news


Oxford Net Zero launches autumn webinar series
Join us this autumn for a series of webinars led by Oxford Net Zero fellows! Read more


Professor Myles Allen appointed Fellow of the Royal Society
Professor Myles Allen appointed Fellow of the Royal Society Read more


Oxford Net Zero is Hiring – Join as Fossil Fuel Fellow
Oxford Net Zero has an exciting opening for a Research Fellow on Net Zero for the Fossil Fuel Sector and non-stipendiary Research Fellowship at Kellogg College. We are seeking to appoint a Research Fellow on Net Zero for the Fossil Fuel Sector ... Read more
See more news and events