Earth spiked a bit of a fever in 2020, partly because of cleaner air from the pandemic lockdown, a new study found.
Overall, the planet was about .05 degrees (.03 degrees Celsius) warmer for the year because the air had fewer cooling aerosols, which unlike carbon dioxide is pollution you can see, the study found.
“Cleaning up the air can actually warm the planet because that (soot and sulfate) pollution results in cooling” which climate scientists have long known, said study lead author Andrew Gettelman, an atmospheric scientist at the National Center for Atmospheric Research. His calculations come from comparing 2020 weather to computer models that simulated a 2020 without the pollution reductions from pandemic lockdowns.
This temporary warming effect from fewer particles was stronger in 2020 than the effect of reduced heat-trapping carbon dioxide emissions, Gettelman said. That’s because carbon stays in the atmosphere for more than a century with long-term effects, while aerosols remain in the air about a week.
Even without the reduction in cooling aerosols, global temperatures in 2020 already were flirting with breaking yearly heat record because of the burning of coal, oil and natural gas — and the aerosol effect may have been enough to help make this the hottest year in NASA’s measuring system, said top NASA climate scientist Gavin Schmidt, who wasn’t part of this study but said it confirms other research.
“Clean air warms the planet a tiny bit, but it kills a lot fewer people with air pollution,” Gettelman said.
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