When environmental activist Greta Thunberg was invited to address the United Nations recently she chose to travel by yacht to hammer home the point that air travel is one of the major contributors to global warming.
As long ago as 2010 a detailed report emerged which suggested that, if we focus just on climate impact over the next five years, planes will account for more global warming than all the cars on the world's roads. Per passenger mile, the threat is even more marked: flying turns out to be on average 50 times worse than driving in terms of a five-year warming impact.
According to figures from German non-profit Atmosfair, flying from London to New York and back generates about 986kg of CO2 per passenger. There are 56 countries where the average person emits less carbon dioxide in a whole year – from Burundi in Africa to Paraguay in South America.
Put simply. planes burn a lot of fuel and therefore kick out plenty of CO2 per passenger. Just as important are a host of other high-altitude impacts, including vapour trails and ozone production, estimated to cause as much warming as the CO2 itself. The issue is that while CO2 released by all fuel-burning vehicles, can remain in the air for centuries, causing a gentle warming effect, the vapour trails and tropospheric ozone produced by planes at altitude cause much stronger and shorter-lived bursts of warming.
Projections suggest that air travel is set to grow even faster than at present, doubling over the next 20 years, and dumping even more greenhouse gases high in the atmosphere.
We know from the research on historical climate change during the last ice age, that the pace of climate change can be rapid. Research has identified 25 distinct warming and cooling cycles, the Dansgaard-Oeschger cycles. One of the most surprising findings was that the shifts from cold to warm occurred in a matter of decades, not millenia
Writing in The Conversation in 2015, Professor Sybren Drijfhout of the University of Southampton said of his research:
“One of the most important findings is that 18 out of 37 abrupt changes are likely to occur when global temperature rises are 2℃ or less, often presented as an upper level of “safe” global warming.”
What should alarm us all is that climate can “flip” quickly on its own. It doesn’t need help from human kind. The increase in global air travel and the short-lived bursts of atmospheric heating it produces could just be a major factor in our climate reaching this tipping point.
