22 Nov 2022
 | 22 Nov 2022
Status: this preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).

Air pollution reductions caused by the COVID-19 lockdown open up a way to preserve the Himalayan snow cover

Suvarna Fadnavis, Bernd Heinold, Thazhe Purayil Sabin, Anne Kubin, Wan Ting Katty Huang, Alexandru Rap, and Rolf Müller

Abstract. The rapid melting of glaciers in the Hindu Kush Himalayas (HKH) during recent decades poses an alarming threat to water security for lager parts of Asia. If this melting persists, the entire Himalayan glaciers is estimated to disappear by end of 21st century. Here, we assess the influence of the spring 2020 COVID-19 lockdown on the HKH, demonstrating the potential benefits of a strict emission reduction roadmap. Chemistry-climate model simulations, supported by satellite and ground measurements, show that lower air pollution during lockdown led to a reduction in black carbon in snow (2–14 %) and thus in snow melting (10–40 %). This caused increases in snow cover (6–12 %) and mass (2–20 %) and a decrease in runoff (5–55 %) over the HKH and Tibetan Plateau, ultimately leading to an enhanced snow-water-equivalent (3.3–55 %). We emphasize the necessity for immediate anthropogenic pollution reductions to address the hydro-climatic threat to billions of people in South Asia.

Suvarna Fadnavis et al.

Status: open (until 10 Apr 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2022-1277', Edward Bair, 04 Mar 2023 reply

Suvarna Fadnavis et al.

Suvarna Fadnavis et al.


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Short summary
The influence of COVID-19 lockdown on the Himalayas caused increases in snow-cover and a decrease in runoff, ultimately leading to an enhanced snow-water-equivalent. Our findings highlight that out of the two processes causing a retreat of Himalayan glaciers: (1) a slow response by global climate change and (2) fast response of local air pollution, a policy action on the latter is more likely to be within reach of possible policy action to help billons of people in south Asia.