Contrails — the wispy ice clouds trailing behind flying jets — “are surprisingly bad for the environment,” reports CNN: A study that looked at aviation’s contribution to climate change between 2000 and 2018 concluded that contrails create 57% of the sector’s warming impact, significantly more than the CO2 emissions from burning fuel. They do so by trapping heat that would otherwise be released into space.
And yet, the problem may have an apparently straightforward solution. Contrails — short for condensation trails, which form when water vapor condenses into ice crystals around the small particles emitted by jet engines — require cold and humid atmospheric conditions, and don’t always stay around for long. Researchers say that by targeting specific flights that have a high chance of producing contrails, and varying their flight path ever so slightly, much of the damage could be prevented.
Adam Durant, a volcanologist and entrepreneur based in the UK, is aiming to do just that. “We could, in theory, solve this problem for aviation within one or two years,” he says…. Of contrails’ climate impact, “80 or 90% is coming from only maybe five to 10% of all flights,” says Durant. “Simply redirecting a small proportion of flights can actually save the majority of the contrail climate impact….”
In 2021, scientists calculated that addressing the contrail problem would cost under $1 billion a year, but provide benefits worth more than 1,000 times as much. And a study from Imperial College London showed that diverting just 1.7% of flights could reduce the climate damage of contrails by as much as 59%.
Durant’s company Satavia is now testing its technology with two airlines and “actively looking for more airlines in 2023 to work with, as we start scaling up the service that we offer.”
Truly addressing the issue may require some changes to air traffic rules, Durant says — but he’s not the only one working on the issue. There’s also the task force of a non-profit energy think tank that includes six airlines, plus researchers and academics. “We could seriously reduce, say, 50% of the industry’s contrails impact by 2030,” Durant tells CNN. “That’s totally attainable, because we can do it with software and analytics.”