Climate change is a significant new threat to public health. This is already the observation of the World Health Organization (WHO) which reports that it is responsible for at least 150,000 deaths per year, a figure which should double by 2030. Among the consequences already expected, we can cite: infectious diseases such as malaria, dengue fever and other infections transmitted by insects, drought and therefore food insecurity, heat waves, asthma and other respiratory diseases. A new study by researchers at the Barcelona Institute for Global Health shows just how much health impacts of climate change will be numerous if no strong strategy and policy is put in place on a global scale.
The study claims that if strong mitigation measures are not implemented immediately, mortality associated with rising temperatures in Europe will increase in the decades to come. “Studies have suggested that global warming will lead to a decrease in the cold-related mortality and an increase in heat deaths. But the drop in cold-related deaths will not offset the expected rapid increase, according to this study heat-related mortality “, Note the researchers. They analyzed mortality and temperature data recorded in 16 European countries between 1998 and 2012. Their results indicate that more than 7% of deaths recorded during this period were attributable to rising temperatures.
The extreme heat, a real danger for the population
While cold temperatures had a greater impact on mortality than hot temperatures, projections based on epidemiological modeling have shown that this trend could be reversed by the middle of the century due to lack of preventive measures, leading to a sharp increase in mortality attributable to heat. Indeed, the prolonged periods of abnormally high temperatures can have serious effects on vulnerable populations, especially the elderly and the sick: this already happened in Europe during the extreme heat wave of 2003, which caused more than 70,000 additional deaths according to WHO estimates. At issue: cardiovascular and respiratory diseases and exacerbated asthma attacks.
Using data from 1998 to 2012 as a baseline, the team combined four climate models to make projections through the end of this century under three scenarios. greenhouse gas emissions different. “All models show a gradual increase in temperatures and therefore a decrease in cold-related mortality and an increase in heat-related deaths. », Explains Èrica Martínez, lead author of the study. “The difference between the scenarios is the speed at which heat-related deaths increase. The data suggests that the total number of temperature-related deaths will stabilize and even decrease in the years to come, but that this will be followed by a very large increase. ”
Heat-related mortality correlates with greenhouse gases
However, this increase could occur between the middle and the end of the century, according to the greenhouse gas emissions : only a drastic reduction in greenhouse gas emissions into the atmosphere is likely to keep the rise in average temperatures below 2 ° C. “In recent decades, warming has occurred at a faster rate in Europe than on any other continent. The incidence of this phenomenon is uneven, Mediterranean countries being more vulnerable than others. Our models project a disproportionate increase in heat-attributable mortality in these countries, due to a significant increase in summer temperatures and this greater heat vulnerability “, Add the researchers.
In its published conclusions in the review The Lancet Planetary Health,the scientific team underlines the urgency of adopting mitigation measures and this at the global level, “because they will not be effective if they are adopted only in specific countries or regions. This same institutiont had already published a study in May 2020 revealing that heat is now more deadly than cold for people with respiratory diseases in Spain. It should be noted that the World Health Organization also considers that the reduction of greenhouse gas emissions, by widening the choice of transport, food and energies, can lead to improved health.