Climate effects from airplanes’ condensation trails to triple by 2050 - study

The condensation trails forming behind airplanes at high altitudes do more damage to the climate than their CO2 emissions and the climate-harmful effects will triple by 2050, according to a paper from the German Aerospace Center (DLR). “Contrails contribute to the warming of the atmosphere to a similar extent as the total CO2 emissions from aircraft since the beginning of aviation,” according to a DLR press release. DLR warns that contrails’ climate impact will triple by 2050 compared to 2006, and that the UN’s Carbon Offsetting and Reduction Scheme for International Aviation (Corsia) does not take into account aviation’s climate impact beyond CO2 emissions. "These effects are expected to increase even faster than the CO2-induced effects as CO2 emissions per passenger-kilometre are already decreasing and research on fuel saving measures continues,” said study co-author Ulrike Burkhardt.

When water vapour and soot from aircraft exhaust fumes meet cold air in higher altitudes, long-lasting ice clouds are formed that contribute to global warming. Cleaning aviation emissions by cutting the soot content of exhaust fumes could alleviate the problem, but not eliminate it, the researchers suggest.

Direct aviation emissions already account for more than 2 percent of global CO2 emissions, roughly equivalent to the total greenhouse gas output of Germany. However, a 1999 special report on aviation prepared by the International Panel on Climate Change (IPCC) estimated the total impact of aircrafts on the climate to be two to four times higher than that of their CO₂ emissions alone.