Aviation is responsible for more global warming than implied by its carbon footprint alone. According to new research published today, aviation could consume up one-sixth of the remaining temperature budget required to limit warming to 1.5˚C by 2050. The article, published in Environmental Research Letters, suggests that emissions produced by the aviation industry must be reduced each year if the sector’s emissions are not to increase warming further.
Given that aviation is widely recognized as a sector which is challenging to decarbonise, this research aims to inform the discussion about aviation’s ‘fair share’ of future warming.
The researchers behind the study, based at the University of Oxford, Manchester Metropolitan University, and the NERC National Centre for Earth Observation, developed a simple technique for quantifying the temperature contribution of historical aviation emissions, including both CO2 and non-CO2 impacts. It also projects future warming due to aviation based on a range of possible solutions to the climate crisis.
Milan Klöwer, lead author of the study said: “Our results show that aviation’s contribution to warming so far is approximately 4% and is increasing. COVID reduced the amount people fly, but there is little chance for the aviation industry to meet any climate target if it aims for a return to normal.”
The authors show that the only way to ‘freeze’ the temperature increase from the sector is to strongly decline CO2 emissions by about 2.5% per year; however, there is room for optimism as they also show that ensuring a 90% mix of low carbon sustainable fuels by 2050 would achieve a similar outcome, with no further temperature increase from the sector. But this relies on a sustainable production chain of low-carbon fuels that does not exist yet, as Milan Klöwer points out. “The aviation industry has to come up with a credible plan for a 1.5˚C world.”