Opinion: Flying less should be a high-priority climate action
Air travel is a significant — and unequally distributed — contributor to climate change, and universities and other institutions with outsized impact need to reduce.
An opinion piece at Ensia recently reported that “flying produces only 2% of total emissions today” and contended, “Even if everyone were to stop flying, the total climate mitigation impact would be negligible.” This understates the impact of aviation for three reasons.
First, the International Energy Association (IEA) reports that just the fuel burn alone for domestic and international aviation was 2.97% of global combustion emissions in 2017, the most recent year available. This percentage was 2.47% in 2009, but the correct figure is higher today.
Second, aviation involves several emissions sources beyond just the jet fuel burn of the actual flight. A life-cycle analysis, such as a 2016 article by Georgia Institute of Technology transportation systems engineering graduate research assistant Haobing Liu and colleagues, includes the transportation to the airport, the energy emissions to produce and transport jet fuel, the ground operations for airports, and the embedded emissions for everything from the aircraft themselves to the airport infrastructure.
Third, aviation is responsible for more “radiative forcing” or (roughly speaking) climate impact than one would expect from the carbon emissions alone, because the emissions take place at high altitude where they induce contrail formation. The U.K. uses a multiplier of 1.9, meaning that the full climate impact of aviation is almost twice as great as the statistics above would indicate. In a 2018 report, Niels Jungbluth, CEO of the sustainability consultancy ESU-Services, and environmental engineer colleague Christoph Meili found research evidence for radiative forcing factors ranging from 1.9 to 5 times the unadjusted number.
A study in the journal Atmospheric Environment led by David Lee, a professor in the Department of Health, Psychology, and Communities at Manchester Metropolitan University, attributed to aviation…