More than a third of all heat-related deaths between 1991 and 2018 are tied to anthropogenic climate change, according to a new study led by the London School of Hygiene & Tropical Medicine (LSHTM). The researchers found that Central and South America have been the hardest hit regions.
The study, which was focused on data from 732 locations in 43 countries, reveals for the first time the contribution of human-induced climate change to heat-related mortality rates.
Overall, the researchers determined that 37 percent of all heat-related deaths during recent summer periods were linked to global warming. The percentages were highest in Central and South America. For example, up to 76 percent of heat-related deaths were tied to anthropogenic warming in Ecuador and Colombia.
“We expect the proportion of heat-related deaths to continue to grow if we don’t do something about climate change or adapt. So far, the average global temperature has only increased by about 1°C, which is a fraction of what we could face if emissions continue to grow unchecked,” said study first author Dr. Ana M. Vicedo-Cabrera from the University of Bern.
The experts calculated the number of heat-related deaths from human-induced climate change that occurred in specific cities. These estimates include 136 additional deaths per year in Santiago de Chile, 189 in Athens, 172 in Rome, 156 in Tokyo, 177 in Madrid, 146 in Bangkok, 82 in London, 141 in New York, and 137 in Ho Chi Minh City.
According to the researchers, their findings are further evidence of the need to adopt strong mitigation policies to reduce future warming, and to implement interventions to protect populations from the adverse consequences of heat exposure.
The team used a “detection & attribution” study, examining past weather conditions simulated under scenarios with and without anthropogenic emissions. This made it possible to distinguish between heat-related deaths linked to human activities, and those linked to natural trends.
“This is the largest detection & attribution study on current health risks of climate change,” said study senior author Professor Antonio Gasparrini. “The message is clear: climate change will not just have devastating impacts in the future, but every continent is already experiencing the dire consequences of human activities on our planet. We must act now.”
The study is published in the journal Nature Climate Change.