Aerosol demasking enhances climate warming over South Asia

Nair, HRCR and Budhavant, K and Manoj, MR and Andersson, A and Satheesh, SK and Ramanathan, V and Gustafsson, � (2023) Aerosol demasking enhances climate warming over South Asia. In: npj Climate and Atmospheric Science, 6 (1).

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Abstract

Anthropogenic aerosols mask the climate warming caused by greenhouse gases (GHGs). In the absence of observational constraints, large uncertainties plague the estimates of this masking effect. Here we used the abrupt reduction in anthropogenic emissions observed during the COVID-19 societal slow-down to characterize the aerosol masking effect over South Asia. During this period, the aerosol loading decreased substantially and our observations reveal that the magnitude of this aerosol demasking corresponds to nearly three-fourths of the CO2-induced radiative forcing over South Asia. Concurrent measurements over the northern Indian Ocean unveiled a ~7% increase in the earth’s surface-reaching solar radiation (surface brightening). Aerosol-induced atmospheric solar heating decreased by ~0.4 K d−1. Our results reveal that under clear sky conditions, anthropogenic emissions over South Asia lead to nearly 1.4 W m−2 heating at the top of the atmosphere during the period March–May. A complete phase-out of today’s fossil fuel combustion to zero-emission renewables would result in rapid aerosol demasking, while the GHGs linger on.

Item Type:	Journal Article
Publication:	npj Climate and Atmospheric Science
Publisher:	Nature Research
Additional Information:	The copyright for this article belongs to the author.
Department/Centre:	Division of Mechanical Sciences > Divecha Centre for Climate Change Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences Others
Date Deposited:	09 Jul 2023 17:33
Last Modified:	09 Jul 2023 17:33
URI:	https://eprints.iisc.ac.in/id/eprint/82074

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