Fast Climate Responses to Aerosol Emission Reductions During the COVID‐19 Pandemic

The reduced human activities and associated decreases in aerosol emissions during the COVID‐19 pandemic are expected to affect climate. Assuming emission changes during lockdown, back‐to‐work and post‐lockdown stages of COVID‐19, climate model simulations show a surface warming over continental regions of the Northern Hemisphere. In January–March, there was an anomalous warming of 0.05–0.15 K in eastern China, and the surface temperature increase was 0.04–0.07 K in Europe, eastern United States, and South Asia in March–May. The longer the emission reductions undergo, the warmer the climate would become. The emission reductions explain the observed temperature increases of 10–40% over eastern China relative to 2019. A southward shift of the ITCZ is also seen in the simulations. This study provides an insight into the impact of COVID‐19 pandemic on global and regional climate and implications for immediate actions to mitigate fast global warming. Key Points Aerosol emission scenarios are produced for lockdown, back‐to‐work, and post‐lockdown stages during COVID‐19 to study fast climate responses An anomalous surface warming appears over the Northern Hemisphere continents in response to aerosol reductions The COVID‐19 emission reduction explains the observed 2019‐to‐2020 temperature increase by 10–40% over eastern China