Record-smashing heatwaves: a looming threat for millions of people globally

The world is heating up, and some regions are more vulnerable than others. A new study by the University of Bristol reveals which communities are most at risk of deadly heatwaves, and why governments must take urgent action to protect them.

A recent global study has uncovered the countries that are most vulnerable to the detrimental impacts of record-breaking heat waves.

The research, led by the University of Bristol and published in the journal Nature Communications, has identified under-prepared regions that are at the greatest risk of suffering from scorching temperatures.

The study reveals that certain areas, such as Afghanistan, Papua New Guinea, and Central America, are particularly susceptible due to a combination of unprecedented heat extremes and socioeconomic vulnerability. The findings suggest that these regions are most likely to experience the devastating effects of heatwaves, including increased mortality rates, energy and healthcare provision issues, and other related harms.

Countries that have yet to face the most extreme heatwaves are particularly vulnerable, as adaptation measures are often implemented only after such events. The likelihood of record-breaking temperatures, coupled with growing populations and inadequate healthcare and energy resources, amplifies the risks. The cities of Beijing and Central Europe are also hotspots, and if they were to experience record-breaking heatwaves, millions of people would be adversely affected.

In response to these findings, the researchers urge policymakers in vulnerable regions to develop action plans that effectively reduce the risk of fatalities and associated harm resulting from climate extremes.

“As heatwaves are occurring more often we need to be better prepared,” remarks lead author, and climate scientist Dr. Vikki Thompson.

“We identify regions that may have been lucky so far – some of these regions have rapidly growing populations, some are developing nations, some are already very hot. We need to ask if the heat action plans for these areas are sufficient.”

To pinpoint the regions globally most likely to experience record-breaking temperatures soonest and the communities in greatest danger of suffering extreme heat, the researchers used a method called extreme value statistics. This involved analyzing large datasets from climate models and observations.

The study’s authors also warned that statistically implausible extremes – when current temperature records are broken by margins that previously seemed impossible – could occur anywhere. These unlikely events were observed in almost a third (31%) of the regions assessed between 1959 and 2021, including the 2021 Western North America heatwave.

They utilized extreme value statistics, which is a technique to evaluate the occurrence periods of rare events, and extensive data sets from climate models and observations to determine the regions around the world where temperature records are most likely to be broken in the near future. These regions are also the ones that are at the greatest risk of experiencing extreme heat and its associated harms.

In addition, the researchers cautioned that statistically implausible extremes, which are instances where current temperature records are shattered by margins that seemed impossible until they actually occurred, could occur anywhere. In fact, they found that these rare and extreme events had already occurred in nearly one-third (31%) of the assessed regions where reliable observations were available between 1959 and 2021, including the 2021 heatwave in Western North America.

“Being prepared saves lives. We have seen some of the most unexpected heatwaves around the world lead to heat-related deaths in the tens of thousands,” adds co-author Dann Mitchell.

“In this study, we show that such record smashing events could occur anywhere. Governments around the world need to be prepared.”

The rise in the frequency, intensity, and duration of heatwaves is attributed to human-induced climate change, posing a potential risk of thousands of excess deaths worldwide.

Enhancing our comprehension of regions unprepared for climate extremes could aid in prioritizing mitigation measures in vulnerable areas.

In 2019, the University of Bristol, acknowledging the severe implications of climate change, declared a climate emergency, becoming the first UK university to do so.

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