31.05.2021 – An international study coordinated by Ana M. Vicedo-Cabrera, researcher of ISPM, in collaboration with the London School of Hygiene & Tropical Medicine shows for the first time the actual contribution of man-made climate change in increasing mortality risks due to heat: between 1991 and 2018, more than a third of all deaths in which heat played a role were attributable to global warming. The study, the largest of this kind, used data from 732 cities in 43 countries around the world and has just been published in the "Nature Climate Change" journal.
Global warming is affecting our health in several ways, and a direct pathway is represented by the increase in mortality and morbidity associated with heat. Scenarios of future climate conditions predict a substantial rise in average temperatures and in the occurrence of extreme events such as heatwaves, leading to future increases in the related health burden. However, so far, no study has evaluated if and to which extent these impacts have already been experienced in the recent decades. The international study, "The burden of heat-related mortality attributable to recent human-induced climate change," coordinated by the University of Bern in Switzerland and the London School of Hygiene & Tropical Medicine (LSHTM) in the UK, now provides evidence on this topic, showing that 37 percent of heat-related deaths between 1991 and 2018 can be attributed to changes in climate related to human activities.
More precisely, the epidemiological investigation focused on man-made global warming, in a so-called "detection & attribution" study that identifies and attributes observed phenomena to changes in climate and weather. Specifically, the researchers examined past weather conditions projected under scenarios with and without anthropogenic emissions, therefore being able to separate the warming and related health impact linked with human activities from natural trends. "We expect the proportion of heat-related deaths to continue to grow if we don't do something about climate change or adapt," says Dr Ana Vicedo-Cabrera, first author of the study and head of the "Climate change and health" research group at the Institute of Social and Preventive Medicine and Oeschger Centre for Climate Change Research at the University of Bern. "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."