Earth had a bit of a fever in 2020, due in part to cleaner air due to lockdowns implemented by the coronavirus pandemic around the world, according to a new study released Tuesday.
For a short period, temperatures in parts of the eastern United States, Russia, and China were 0.3 to 0.7 degrees Celsius (half and two-thirds of a degree Fahrenheit) warmer. That’s because of less soot and sulfate particles from car exhaust and burning coal, which normally cools the atmosphere temporarily by reflecting the sun’s heat, the study published in the journal Geophysical Research Letters said.
In total, the planet was 0.03 ° C (0.05 ° F) warmer in 2020 because the air had fewer aerosols, which unlike carbon dioxide is a type of pollution that can be observed, the study found.
“Cleaning the air can actually warm the planet because pollution (with soot and sulfates) causes cooling,” something climate scientists have long known, said Andrew Gettelman, lead author on the study and an atmospheric scientist at the National Center for Atmospheric. Research. Their calculations come from comparing the 2020 climate with computer models that simulated 2020 without the reduction of pollution from landfills.
This temporary warming effect of less particulate matter was stronger in 2020 than the effect of reduced carbon dioxide emissions, Gettelman said. That’s because carbon stays in the atmosphere for over a century with long-term effects, while aerosols stay in the air for about a week.
Even without the reduction in aerosols, global temperatures in 2020 were already close to breaking the annual record for heat from the combustion of coal, oil and natural gas, and the effect of the aerosols could have been enough to help that year was it NASA’s measurement system, said NASA’s chief climate scientist Gavin Schmidt, who was not involved in the study, but said it confirms other research.