Contrail management – now!

Abstract

Flying is booming and with it the CO2 emissions. It is is not easy to decarbonize aviation. Whether electric drives, e-fuels, or green hydrogen, so far there is no convincing climate-friendly option for propulsion in air transport. And now? In addition to drastic flight restrictions, there is another way forward. Flights just need to be rerouted to fly a little higher or lower. Why? Large passenger and cargo jets are flying at an altitude of around 11000 m. In these regions water vapor condenses with soot from the engine exhaust to ice crystals forming contrails behind the aircraft. They can remain visible for many hours, when humidity is high. Especially at dawn, dusk and at night contrails are warming, because they act like panes of glass in a greenhouse. CO2 from aircraft fuel accounts for only one third of the warming effect measured in equivalent CO2. In contrast, contrails can cause more than half of the equivalent CO2. Experts in various fields of aviation explain unanimously that contrail management could start now! How is it done? Who knows what? Who is prepared? Who is against it?