Switzerland: One in three heat deaths a climate consequence
An international study coordinated by the University of Bern and the London School of Hygiene & Tropical Medicine shows for the first time the actual contribution of man-made climate change to heat-related deaths. Between 1991 and 2018, more than a third of all deaths in which heat played a role were attributable to global warming.
Global warming has various effects on health. One direct effect is the increase in heat-related illness and mortality rates. According to scenarios, average temperatures will rise considerably and extreme weather events such as heat waves will occur more frequently. This will also lead to an increase in the associated health burden in the future. To date, no study has investigated whether and to what extent such effects have already occurred in recent decades. The international study "The burden of heat-related mortality attributable to recent human-induced climate change," coordinated by the University of Bern and the London School of Hygiene & Tropical Medicine (LSHTM), now shows for the first time that 37 percent of heat-related deaths between 1991 and 2018 can be attributed to human-induced climate change.
The more global warming, the more deaths
More specifically, the epidemiological study examined the effects of the man-made Climate warming analyzed. This was done in a so-called "detection & attribution" study, which assigns the human-induced part to climate warming. Specifically, the researchers examined past weather conditions under scenarios with and without human influence, and were able to separate human-induced warming and associated health effects from natural changes. "We expect the proportion of heat-related deaths to continue to grow if we don't do anything about climate change or adapt," said Ana Vicedo-Cabrera, lead author of the study from the Institute of Social and Preventive Medicine and the Oeschger Center for Climate Research at the University of Bern. "So far, the global average temperature has only increased by about 1°C, which is a fraction of what we could face if emissions continue to grow unchecked."
Regional differences in heat-related health risks.
While on average more than one-third of heat-related deaths are attributable to human-induced climate change, the impacts vary significantly by region. The number of climate-related heat casualties ranges from a few dozen to several hundred deaths each year, depending on the local climate changes in each area and the vulnerability of the population. People in low- and middle-income countries in Central and South America and Southeast Asia, which have historically accounted for only a small fraction of anthropogenic emissions, are most affected. "Our study represents the most comprehensive investigation into the detection and attribution of current health risks related to climate change," said Antonio Gasparrini, lead author of the study from the London School of Hygiene & Tropical Medicine. "The message is clear: Climate change will not only have devastating effects in the future, but we are already experiencing the severe consequences of human activities on our planet."
One in three heat-related deaths in Switzerland is due to climate change
Even in Switzerland, with comparatively small differences in living conditions and still moderate temperatures, heat risks "should not be underestimated," as Ana Vicedo-Cabrera says. For example, one in three heat deaths can be attributed to climate change, as the estimate for Switzerland is around 30 percent.
Research on climate change and health is one of the main topics of the Oeschger Center for Climate Research. A corresponding research group was founded in 2019 together with the Institute of Social and Preventive Medicine (ISPM) of the University of Bern. It is led by Ana M. Vicedo-Cabrera, first author of the just published international study on heat mortality and climate change.
The study, "The burden of heat-related mortality attributable to recent human-induced climate change," is the largest study of its kind to date, with data from 732 cities in 43 countries worldwide.
Source: University of Bern
Other topics:
