Extreme heat and cold kill five million every year

Heatwave over the Feleacu hills, Cluj-Napoca, Romania: Extreme heat will strike more often. Image: By Lucian Dachman on Unsplash 

Five million people die annually of ever more extreme temperatures. And this is happening now on five continents.

LONDON, 9 July, 2021 − Extremes of hot and cold weather now claim around five million lives a year worldwide. Deaths related to heatwaves have been on the increase this century, and global heating driven by fossil fuel combustion will make things worse, according to new research.

A second study in the same journal warns that, even in Europe, there will be a rapid increase in heat-related mortality − unless mitigation measures are introduced immediately.

In the first study, scientists in China, Australia, the UK and Moldova report in the journal The Lancet Planetary Health that they looked at death statistics and temperature readings from 570 locations in 43 nations on five continents between the years 2000 and 2019, a period when average global temperatures rose by 0.26°C a decade.

They found that 9.43% of global deaths could be attributed to either very hot or very cold temperatures: that means 74 excess deaths for every 100,000 people. During that time, cold-related deaths fell by 0.51%; heat-related deaths increased by 0.21%. Worldwide, they estimate, the statistics translate to 5,083,173 deaths per year.

“The total number of temperature-attributable deaths will stabilise in the coming years, but … this will be followed by a very sharp increase”

The last 20 years have been the hottest since records began. The news comes close upon lethal heat extremes in Canada, and Oregon and Utah,  and other parts of the US southwest.

High temperatures can and do kill: one group counted 27 ways to die of rising temperatures. Nor should such calculations come as a surprise: researchers have repeatedly warned of potentially murderous extremes linked to global heating driven by ever-rising ratios of greenhouse gases in the atmosphere.

These extremes will last longer, extend over wider regions and reach more intense temperatures in the coming decades.

More than half of all deaths linked to abnormal temperatures were in Asia, but Europe had the highest excess death rates per 100,000 people due to heat exposure.

Mediterranean at risk

A second study in The Lancet Planetary Health confirms the hazard even in a climate zone usually considered temperate. Researchers from Spain, France and Switzerland looked at death and temperature data for 16 European countries between 1998 and 2012, to conclude that more than 7% of all deaths registered during this period could be linked to temperature: extreme cold was 10 times more likely to kill than extreme heat.

But, the scientists warn, by mid-century this trend could be reversed. A disproportionate number of people in the Mediterranean basin could be especially at risk, according to projections based on three different climate scenarios.

“All of the models show a progressive increase in temperatures and, consequently, a decrease in cold-attributable mortality and an increase in heat-attributable deaths,” said Èrica Martínez, of the Barcelona Institute for Global Health, who led the research.

“The difference between the scenarios lies in the rate at which heat-related deaths increase. The data suggest that the total number of temperature-attributable deaths will stabilise and even decrease in the coming years, but that this will be followed by a very sharp increase, which could occur some time between the middle and the end of the century, depending on greenhouse gas emissions.” − Climate News Network