Mild winters may be the new normal, says study

PUNE: Mild winters could be the norm in the coming decades, according to temperature projections in a study by the Centre for Climate Change and Adaptation Research in Chennai.

The study, which looked at the impact of greenhouse gases on India’s climate, said minimum temperatures could rise more rapidly in the coming decades as greenhouse gases have a higher impact at night.

Projections from the study indicate annual mean minimum temperatures in India could rise 0.9 degrees celsius by the 2020s, 2.3 degrees celsius by 2050s and 3.6 degrees celsius by 2080s, as compared with the 1975-2005 reference period.


Prasanta Kumar Bal, former scientist at the Centre for Climate Change and Adaptation Research in Chennai, said night temperatures would rise in the range of 2.8-4.7 degrees celsius for different projections by the end of this century.

“Greenhouse gases have a higher impact at night when they absorb infrared radiation and reduce the cooling. This effect is more intense than daytime warming. Therefore, the increase in the minimum temperature is more rapid than the maximum temperature. There is a negative trend in the diurnal temperature range during the end of the century, which indicates that the minimum temperatures are warming faster than the maximum temperatures,” Bal said.

The study also forecasts harsher summers in northwest India (Punjab, Haryana, Rajasthan and Gujarat) by 2080s, which could see a 3.1-degree rise in temperatures during March, April and May.

A K Srivastava, senior scientist and head of the climate monitoring and analysis group at India Meteorological Department, Pune, said observed changes in temperature since 1901 indicate that the minimum temperature in the country began rising rapidly after the 1980s.

“Apparently, the increase in pollutants and greenhouse gases after the 1980s seem to hinder the earth’s outgoing long wave radiation at night, leading to an increase in night temperature,” he added.