2020 global lockdown had impact on jet aircraft-induced climate change

A new study led by researchers from the University of Leipzig in Germany has proven that high-flying jets do have an impact on global warming by producing additional high clouds, in addition to greenhouse gases.

The research team was able to reach their conclusion by comparing the amount of high-altitude cirrus clouds produced by jet aircraft during the global pandemic lockdown from March to May of 2020 to that of the same period during previous years.

Cirrus clouds, known for their high, wispy strands, contribute to warming the climate. When cirrus clouds occur naturally, large ice crystals form at an altitude of about 36 kilometres, in turn reflecting sunlight back into space – albeit to a small extent. However, they also prevent radiated heat from escaping the atmosphere, and thus have a net heating effect, according to the University of Leipzig report.

High clouds caused by contrails in the western U.S.

The researchers were specifically focused on the condensation trails that persisted behind aircraft and formed larger cirrus clouds.

During the lockdown period, where there was a significant decrease and shift in air traffic routes, the team found that there was a 9% decrease in cirrus clouds during the lockdown and that the clouds on average were about 2% less dense than previous years.

Key excerpts from the study.......

“The study clearly demonstrates that aircraft contrails lead to additional cirrus clouds and have an impact on global warming," said Professor Johannes Quaas, who was the lead author of the study. “Our study may improve the ability to simulate these effects in climate models."

“The tough global lockdown has been helpful in terms of our research. In order to mitigate or even avoid the warming effect on the climate, flight routes could be adapted in the future to avoid cirrus cloud formation, for example by separating flight corridors," said Quaas.