According to a recent study, more than a third of all deaths involving heat in the period 1991-2018 were attributable to man-made global warming.
Researchers from the London School of Hygiene & Tropical Medicine (LSHTM) and the University of Bern used data from 732 sites in 43 countries around the world to estimate the real contribution of human-induced climate change to the increasing death risks from heat. show.
Overall, estimates show that 37 percent of all heat-related deaths in recent summer periods were due to global warming due to human activities.
This percentage of heat-related deaths attributed to human-induced climate change was highest in Central and South America (up to 76 percent in Ecuador or Colombia, for example) and Southeast Asia (between 48 and 61 percent).
The authors say 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 ill effects of heat exposure.
First author of the study Dr. Ana M. Vicedo-Cabrera said: “We expect the share of heat-related deaths to continue to grow if we do not act on climate change or adapt.
So far, the average temperature on Earth has only increased by about 1 ° C, which is a fraction. of what we might encounter if emissions continue to grow uncontrolled.
” The study warns that with future climate conditions predicting a significant increase in average temperatures, extreme events such as heatwaves could lead to a further increase in heat deaths.
The team examined past weather events simulated in scenarios with and without by the human-caused emissions.
This allowed them to separate the warming and associated health effects associated with human activities from natural trends.
Heat-related mortality was defined as the number of deaths attributed to heat, occurring at exposures above the optimum temperature for human health , which varies by location.
While on average more than a third of heat-related deaths are due to human-induced climate change, the impact varies considerably from region to region.
Climate-related heat casualties range from a few dozen to several hundred deaths per year per city, depending on the local climate changes in each area and the vulnerability of the population.
Populations in low- and middle-income countries, which in the past were responsible for a small proportion of anthropogenic emissions, are most affected.
In the UK, 35 per cent of heat-related deaths can be attributed to human-induced climate change, equivalent to around 82 deaths in London, 16 deaths in Manchester, 20 in the West Midlands or 4 in Bristol and Liverpool each summer season.
“This is the largest detection and attribution study of the current health risks of climate change,” said the study’s senior author, Professor Antonio Gasparrini of LSHTM.
“The message is clear: not only will climate change have devastating consequences in the future, but every continent is already experiencing the dire consequences of human activities on our planet. We must act now. “