Unstable temperatures as bad as air pollution in causing death

Extreme events such as heatwaves are having a negative impact on human health, even resulting in death. However, few of us are aware of how another challenging aspect of climate change, namely erratic temperatures, affects our health. Reflecting the lack of stability in weather, this aspect – and its impact on worldwide mortality – has not received much attention. A recent study published in the journal ‘The Lancet Planetary Health’ now provides a clearer picture of the global burden of mortality associated with temperature variability.

Supported in part by the EU-funded EXHAUSTION project, the study reveals the annual number of deaths associated with unstable temperatures. “Climate change is a major public health concern of the 21st century,” observes the study’s senior author Prof. Yuming Guo of Monash University, Australia, in a news item posted on the ‘Medical Xpress’ website. “Our findings show that temperature variability has similar impacts to air pollution on global mortality.”The study reports a rising trend of erratic temperatures worldwide from 2000 to 2019. Using data from the Multi-Country Multi-City Collaborative Research Network run by EXHAUSTION project partner London School of Hygiene and Tropical Medicine, the researchers explored the association between temperature variability and mortality in 750 cities across 43 countries or regions. They discovered that during this 20-year period more than 1.75 million deaths around the world were associated with unstable temperatures each year. In addition, most of Asia, Australia and New Zealand were found “to have a higher percentage excess in mortality than the global mean,” according to the study. Excess mortality refers to the number of deaths that occur during a crisis beyond what we would have expected under normal conditions.

Globally, the percentage excess in mortality increased by about 4.6 % per decade between 2000 and 2019. The research team found the largest increase per decade to have occurred in Australia and New Zealand (7.3 %), followed by Europe (4.4 %) and Africa (3.3 %).

“With temperatures becoming increasingly unstable, proactive countermeasures are necessary to protect human health against temperature variability,” remarks Prof. Guo in the news item. “Many policies have been developed to cope with the threat of climate-related extreme events, for example, warning systems for heatwaves and air pollution. However, these policies and strategies rarely exist to cope with the adverse health impacts of temperature variability.”

The study conducted with support from EXHAUSTION (Exposure to heat and air pollution in EUrope – cardiopulmonary impacts and benefits of mitigation and adaptation) could help raise public awareness and improve understanding of the issue. It also highlights the need for coordinated actions and more targeted policies to prevent temperature variability-related deaths, especially in regions more greatly affected by unstable temperatures.

For more information, please see:

EXHAUSTION project website