Dubbling Climate change as the primary cause for the latest heatwave in India, scientists from across the world who joined hands to study the 2022 heatwave in India and Pakistan--estimated to have led to about 90 deaths--said the phenomenon began too early and was 30 times more likely due to human-caused climate change.
As many as 29 researchers from the World Weather Attribution group, including scientists from leading institutes in India, Pakistan, France, the US, the UK and other countries collaborated for the rapid attribution study of the heatwave, termed as a "rare event".
While data for both the countries (from 1979) was considered too short to estimate the exact return period of such a rare event, officials studied data that only covers India (from 1951) and made serious findings.
Under the present climatic condition of 1.2 degrees Celsius global warming, the return period could be around 100 years or one event in a century. However, the continuous rising in the temperature has made things worse. The event is 30 times more likely compared with the pre-Industrial times and 1 degree C warmer.
"Because of climate change, the probability of an event such as that of 2022 has increased by a factor of about 30. With future global warming, heatwaves like this will become even more common and hotter," the study said.
While heatwaves were not uncommon in this part of the world in the pre-monsoon season, prior studies reported the occurrence of such extremes in the later months, primarily May and June. More importantly, earlier studies had said heatwaves in India were common in north-central parts and coastal regions of eastern India.
It changed this year as almost 70% of India and 30% of Pakistan were affected by heatwaves in April and May. "The heat reduced India's wheat crop yields, causing the government to reverse an earlier plan to supplement the global wheat supply that has been impacted by the war in Ukraine," the study said.
The shortage of coal in India led to power outages that limited the access to cooling, compounding health impacts and forcing millions of people to use coping mechanisms such as limiting activity to the early morning and evening.
The study 'Climate Change made devastating early heat in India and Pakistan 30 times more likely', is yet to be peer-reviewed.
Mariam Zacharia, one of the 29 authors, said the scientists took the observations and tested the data with climate models to investigate the phenomenon with and without climate change scenarios.
Aditi K Kapoor from RCRC Climate Centre said street vendors, construction and farm workers, traffic police and those who were exposed to the hot weather suffered the most. She said the heatwave action plans have to be scaled up to cover the protection of the livelihoods of the vulnerable.