An international team of researchers found that between 1991 and 2018, more than a third of all deaths in which extreme temperatures played a role were associated with global warming. This is reported in the journal Nature Climate Change.

The largest study of its kind was led by the London School of Hygiene and Tropical Medicine (LSHTM) and the University of Bern as part of the Multi-Country Multi-City (MCC) Collaborative Research Network. Using data from 732 localities in 43 countries of the world, they showed for the first time the real contribution of anthropogenic climate change to an increased risk of heat-related deaths.

Their estimates showed that 37% of all heat deaths in summer were associated with warming of the planet as a result of anthropogenic activity. The percentage of deaths caused by global warming was highest in Central and South America (up to 76%, for example in Ecuador or Colombia) and Southeast Asia (48% to 61%).

Their estimates also show the number of deaths from anthropogenic climate change that occurred in specific cities: 136 deaths per year in Santiago de Chile (44.3% of the total number of heat deaths in the city), 189 in Athens (26.1%) , 172 in Rome (32%), 156 in Tokyo (35.6%), 177 in Madrid (31.9%), and so on. The authors say their findings provide further evidence of the need for drastic action to reduce future warming.

“We expect the proportion of heat-related deaths to continue to rise unless we do anything about or adapt to climate change. So far, the average global temperature has risen by only 1 ° C, which is a small fraction of what we may be facing. Especially if emissions continue to rise uncontrollably, ”said researchers from the University of Bern.

The scientists added that global warming affects health in several ways, from direct effects associated with wildfires and extreme weather conditions to changes in the spread of vector-borne diseases. However, they also added that the rise in mortality and morbidity is still too high. Given that future climate scenarios predict significant increases in average temperatures, extreme events such as heat waves will pose even greater risks to human health.