India to face irreversible impacts of climate crisis says IPCC report

Glacial retreat in the Hindu Kush Himalayas, compounding effects of sea-level rise and intense tropical cyclones leading to flooding; an erratic monsoon, and intense heat stress are likely to impact India in recent years, the Intergovernmental Panel on Climate Change (IPCC) has indicated.

Most of these impacts are irreversible and hence cannot be remediated even if greenhouse gas emissions decline dramatically, the IPCC said.

The IPCC report titled 'Climate Change 2021: The Physical Science Basis' released on Monday said heatwaves and humid heat stress will be more intense and frequent during the 21st century over South Asia.

The Indian Ocean, which includes the Arabian Sea and Bay of Bengal, has warmed faster than the global average, the IPCC said with "very high confidence". The oceans factsheet released by IPCC on Monday indicates that sea surface temperature over Indian ocean is likely to increase by 1 to 2 degrees C (°C) when there is 1.5°C to 2°C global warming.

Over high mountains in Asia which include the Himalayas, snow cover has reduced since the early 21st century, and glaciers have thinned, retreated, and lost mass since the 1970s, the IPCC said, although the Karakoram glaciers haven't recorded any major retreating trend.

Snow-covered areas and snow volumes will continue to decrease during the 21st century, snowline elevations will rise and glacier mass is likely to decline further as emissions rise. Rising global temperature and rain can increase the occurrence of glacial lake outburst floods (GLOFs) and landslides over moraine-dammed lakes, the IPCC warned.

Heat extremes have increased while cold extremes have decreased, and these trends will continue over the coming decades over Asia. This the first time IPCC has released regional factsheets. The Asia projection maps indicate annual mean temperatures will increase by 1-2°C relative to 1850-1900 period in case of 1.5°C to 2°C global warming. There are likely to be 90 to 120 days in a year with maximum temperatures above 35°C in case of 1.5 to 2°C warming and over 180 days in case of 4°C warming.

Marine heatwaves will continue to increase. Fire weather seasons will lengthen and intensify, particularly in North Asia regions. Mean surface wind speeds have decreased and will continue to decrease in central and northern parts of Asia.