Study Shows COVID-19 Quarantine Lowered Pollution, Raised Global Temp

This week the folks at the National Center for Atmospheric Research (NCAR) published a study on the effects of the COVID-19 pandemic and subsequent global lockdown. "Pollution cools the planet, so it makes sense that pollution reductions would warm the planet, said NCAR scientist Andrew Gettelman.

"There was a big decline in emissions from the most polluting industries, and that had immediate, short-term effects on temperatures," said Gettelman. Gettelman went on to outline how aerosols have an immediate impact, but fade away in a few short years.

Reduced emissions of carbon dioxide as a result of the lockdown may have had a bigger overall impact. Because of a lowering of carbon dioxide emissions, long-term impacts may be a slowing of climate change – that's a good thing.

ABOVE: FaIR model estimates of (a), (c) Effective Radiative forcing and (b), (d) component temperature response for aerosols. Tropospheric ozone (purple), CO2 (orange), Contrails (red) and Total (blue) from Forster et al. (2020). A,B use aerosol ERF from Figures 2c and 2d use the Aerosol ERF from Forster et al. (2020). O3, CO2 and contrails are updated from Forster et al. (2020). ERF, effective radiative forcing.

Per the study, peak aerosol changes were the largest contribution to radiative forcing and temperature changes as a result of COVID-19 affected emissions. These were larger than ozone, CO2, and contrail effects. The impact of the changes on global surface temperature are "estimated to be very small" and transient over several years.

The study also suggested that they're not yet able to account for all earth system dynamics – especially those that only really come into play with observations over the course of years, not just months. The short-term effects and most obvious results are that – yes – this global lockdown DID have an impact on the temperature of our planet and the path we're on right this minute.

You can learn more about the study in the paper Climate Impacts of COVID‐19 Induced Emission Changes with code DOI: 10.1029/2020GL091805 as released in the February 16, 2021 issue of Geophysical Research Letters. This paper was authored by A. Gettelman, R. Lamboll, C. G. Bardeen, P. M. Forster, and D. Watson-Parris.