Who would have thought that besides stopping the spread of the deadly Covid-19 Coronavirus, the lockdown imposed by the government also helped the world in general and India in particular in the ongoing fight to combat the climate change.
The five-week-long lockdown that India imposed in the year 2020 resulting in prevention of as many as 27 metric tonnes of ice and snow melt in the Himalayas, it has come to fore. The Hindu Kush Himalayan Region is also called the third pole because of the volume of glacial ice it stores. These glaciers, which are the source of 10 major river systems, are warming much faster than the global average. Snow and ice on the Tibetan plateau act as a water source for over 20 per cent of the global population.
However, ice and snow in the Himalayas have been melting at an accelerating rate in recent decades. Scientists have recorded a retreat in both snowfall and glacial mass in Ladakh over the last few decades. Snowmelt and rainfall in the months of March and April would irrigate their fields enough to sow barley, wheat, peas, and potatoes. But with lower levels of snowfall, the sowing season has gone awry. While much of this melting is attributable to climate change, air pollution also plays a role, because dark particles of dust and soot that fall on frozen surfaces absorb solar energy and melt the nearby snow and ice.
A new study has revealed that as many as 27 metric tonnes of ice and snow melt in the Himalayas had been prevented by the Indian national lockdown, in place from March 25, 2020, to May 31, 2020. Diminished anthropogenic pollutant emissions during the 2020 Covid-19 lockdowns reduced snowmelt in the Himalayas, the study published in Proceedings of the National Academy of Sciences (PNAS) Nexus said. Liqiang Zhang from Beijing Normal University, China, and colleagues explored how the sudden, dramatic reduction in particulate pollution in the region affected snow and ice melt, using multiple satellite data as well as a coupled atmosphere-chemistry-snow model.
The authors estimate that the reduced anthropogenic pollutant emissions during the Indian lockdown was responsible for 71.6 per cent of the reduction in radiative forcing on snow in April 2020 compared to the same period in 2019. This reduction in radiative forcing may have prevented 27 MT in ice and snow melt. The results emphasised the power of reducing anthropogenic pollutant emissions when combating snow and ice melt, the study says.
If anything, the study only underlines the contribution of human activities in the melting of ice and glaciers. The rising temperature of the earth has without doubt been responsible for melting glaciers throughout history, only aggravated due to greater pace of development in the recent past. In order to curtail climate change and save the glaciers, it is indispensable that global CO2 emissions be reduced by 45 % over the next decade, and that they fall to zero after 2050.
