The increasingly extreme temperatures that we can expect in many parts of the world over the coming decades as a result of anthropogenic climate change will considerably drive up aviation industry operating costs — owing to a need to regularly reduce takeoff weights when temperatures climb too high. That news is according to a new study from Columbia University.
The study predicts that the coming decades will see 10–30% of fully loaded planes being forced to remove cargo, passengers, or fuel — or wait until temperatures drop — to achieve lift off.
To explain: As air gets warmer, it spreads out more and density drops. As a result, the lift generated by airplane wings during takeoff is reduced. What that means is that, all else being equal, the warmer it gets, the less weight an airplane can carry if it is going to get off the ground.
“Our results suggest that weight restriction may impose a non-trivial cost on airline and impact aviation operations around the world,” commented lead author Ethan Coffel, a Columbia University PhD student.
The press release provides more: “In 2015, they published a smaller-scale paper, predicting up to four times more future temperature-related takeoff problems for the common Boeing 737-800 at Phoenix, as well as Denver, New York’s LaGuardia and Washington’s Ronald Reagan. The new study projects effects on a wide range of jets at these, plus 15 of the other busiest airports in the United States, Europe, the Mideast, China, and south Asia.
“The authors estimate that if globe-warming emission continue unabated, fuel capacities and payload weights will have to be reduced by as much as 4% on the hottest days for some aircraft. If the world somehow manages to sharply reduce carbon emissions soon, such reductions may amount to as little as 0.5%, they say. Either figure is significant in an industry that operates on thin profit margins. For an average aircraft operating today, a 4% weight reduction would mean roughly 12 or 13 fewer passengers on an average 160-seat craft. This does not count the major logistical and economic effects of delays and cancellations that can instantly ripple from one air hub to another, said Horton.”
Those knock-on effects could themselves be quite substantial.
The press release continues: “Some aircraft with lower temperature tolerances will far worse than others, and certain airports — those with shorter runways, in hotter parts of the world or at higher elevations, where the air is already thinner — will suffer more. For instance, facing LaGuardia’s short runways, a Boeing 737-800 may have to offload weight half the time during the hottest days. Dubai, in the United Arab Emirates, might be worse; its runways are long, but its temperatures are already very high.”
According to the researchers, new engine or body designs could potentially help mitigate some of the above discussed problems, but these redesigns would of course themselves come at a price. Expanded runways are another possibility, though they are not cheap either.
Overall, the takeaway of the work is clear: All else being equal, air travel is slated to become more expensive and less convenient in most parts of the world over the coming decades. Don’t be too surprised if it again becomes something for the rich only, as it once was, before the middle of the century arrives.
The new study was published in the journal Climatic Change.