New research examining data spanning 30 years since 1990 has revealed that more than 1.53 lakh deaths annually worldwide were linked to heatwaves. India accounted for over a fifth of these deaths, marking the highest share. Following India, China and Russia experienced approximately 14 percent and 8 percent of these heatwave-related excess deaths, respectively.
Led by Monash University, Australia, a study revealed that heatwave-associated excess deaths comprised around one-third of all heat-related deaths and 1 percent of total global deaths. Of the total 1.53 lakh excess deaths each summer, nearly half originated from Asia and over 30 percent from Europe. Notably, regions with dry climates and lower-middle incomes exhibited the highest estimated death rates (deaths per population). These findings are published in PLoS Medicine.
"During the warm seasons from 1990 to 2019, heatwave-related excess deaths accounted for 153,078 deaths per year, a total of 236 deaths per ten million residents or 1 per cent of global deaths," the authors wrote. For the study, the researchers used data from the UK-based Multi-Country Multi-City (MCC) Collaborative Research Network that included daily deaths and temperatures from 750 locations across 43 countries.
A comparison between the decade leading up to 2019 and that up to 1999 revealed an extension in the duration of heatwaves each year from an average of 13.4 to 13.7 days worldwide, accompanied by an average ambient temperature warming of 0.35 degrees Celsius per decade. The researchers emphasized that while earlier studies have assessed excess deaths due to heatwaves on a local scale, there hasn't been a comparison of these estimates globally over an extended period until now.