According to a new study, deadly heatwaves will continue and become more commonplace in South Asian countries, including India, even if global warming is limited to 1.5 degrees Celsius.
The study, published in the journal Geophysical Research Letters, was conducted by scientists, including those from Oak Ridge National Laboratory in the US.
The researchers used climate simulations and projections of future population growth in the study to estimate the number of people who will experience dangerous levels of heat stress in South Asia at global warming levels of 1.5 and 2 degrees Celsius.
According to the findings, a wet-bulb temperature of 32 degrees Celsius is considered the point when labour becomes unsafe, and 35 degrees Celsius is the limit to human survivability when the body can no longer cool itself.
Wet-bulb temperature is the lowest temperature to which air can be cooled by the evaporation of water into the air at a constant pressure.
The scientists said 2 degrees of warming might increase people's exposure to unsafe labour temperatures by more than two-fold and exposure to lethal temperatures by 2.7 times compared to the recent years.
Scientists fear that the increase in extreme heatwaves could have a catastrophic impact by creating unsafe labour conditions in major crop-producing parts of India, such as Uttar Pradesh and West Bengal, coastal regions, and urban centres like Kolkata, Mumbai, and Hyderabad.
Moreover, cities in South Asia that are densely populated already lack regular access to air conditioning, and about 60 per cent of the population perform agricultural work and cannot escape the heat by staying indoors.
"Even at 1.5 degrees, South Asia will have serious consequences in terms of heat stress. The future looks bad for South Asia, but the worst can be avoided by containing warming to as low as possible. The need for adaptation over South Asia is today, not in the future. It's not a choice anymore," said researcher Moetasim Ashfaq from the Oak Ridge National Laboratory in the US.
Researchers are now demanding the government soon comes up with a proper policy framework to fight against the deadly heatwaves.