More than 153,000 deaths worldwide per year are linked to heat waves between 1990 and 2019.
- More than 153,000 deaths per hot season were associated with heat waves between 1990 and 2019.
- This represents 236 additional annual deaths per 10 million inhabitants per hot season.
- For researchers, it is essential to take measures to improve the adaptation and resilience of the health sector, taking into account inequalities between communities.
Over the past decade, global temperature has increased by 1.14℃ compared to the pre-industrial era (1850-1900). And the thermometer is expected to rise further from 0.41 to 3.41℃ by 2081-2100, according to scientists. These worrying figures lead them to question the impact of climate change on health, especially as heat waves are becoming more and more frequent and severe.
Heat waves: no region of the world is safe
To understand the impact of climate change on mortality, Professor Yuming Guo from Monash University examined data on daily deaths and temperature from 750 sites in 43 countries or regions.
The work shows that between 1990 and 2019, heat waves were responsible for 153,078 deaths per hot season between 1990 and 2019. This represents 236 additional annual deaths per 10 million inhabitants.
While almost half of the additional deaths linked to heatwaves occurred in Asia, the regions with the largest increases in deaths linked to peak temperatures were southern and eastern Europe, areas with polar climates and alpine as well as those where residents had high incomes.
“Many researches have reported that the same extremely high temperature may be less harmful in warm regions than in cold regions, and explained that this phenomenon is due to long-term acclimation to local heat”explain the authors in their article published in the journal PLOS Medicine on May 14, 2024.
What about the disparity observed among wealthy populations? “One possibility is that in high-income countries there is a larger older population, which would be more vulnerable to heat waves”explains Professor Guo to the newspaper Courtoise News Service. “And people in high-income countries, having adapted to the use of air conditioning, could experience more pronounced impacts from increased heat waves.”
However, the authors point out that the whole world is affected by rising temperatures. “The results of this study suggest that no region of the world is immune from the impact of heatwave mortality in the context of climate change,” they write in their article.
Rising temperatures and health: we must anticipate the risks
Researchers point out that heat waves lead to an increased risk of death due to heat stress (inability of the human body to maintain a normal temperature), the triggering of dysfunction of several organs or even exhaustion due to high temperatures. . They add that heat stress can worsen pre-existing psychiatric disorders and chronic illnesses, leading to premature death.
For the team, its work shows that it is necessary to take into account the impact of rising temperatures on health.
“Our findings that heatwaves are associated with a significant mortality burden that varies spatio-temporally across the world over the past 30 years, suggest that there should be adaptation planning (from the heat sector health) and localized risk management at all government levels”concludes Professor Yuming Guo in a communicated.