Study Projects Millions of European Heat Deaths as World Warms

Extreme temperatures—mostly heat—are projected to kill as many as 2.3 million people in Europe by the end of the century unless countries get better at reducing carbon pollution and adapting to hotter conditions, a new study says.

Currently, cold temperatures kill more people in Europe than heat by large margins. But a team from the London School of Hygiene and Tropical Medicine used climate simulations of different scenarios and looked at death rates in 854 cities. They found as it warms cold deaths lessen slowly, but heat deaths soar rapidly.

With few reductions in emissions of greenhouse gases and little adaptation like air conditioning and cooling centres, Italy, southern Spain, and Greece should see massive increases in the rate of heat deaths due to climate change. On the flip side, much of Scandinavia and the United Kingdom will see fewer temperature-related deaths, mostly due to moderating cold temperatures, the study in Monday’s journal Nature Medicine found.

But even in the most optimistic scenarios—with carbon dioxide emissions from coal, oil, and gas cut sharply and massive increases in adaptation—there’s a net increase in temperature-related deaths as the world warms, said study lead author Pierre Masselot, an environmental epidemiologist and statistician.

The dropoffs in cold deaths up north are in places not as populated as places further south, where the heat really kicks in and hurts, Masselot said.

“The Mediterranean is a so-called climate hotspot,” Masselot said. “It’s a region that is warming much quicker than the rest of the world. And Malta is right in the middle of it.”

The study projects Malta’s temperature-related death rate to increase by 269 people for every 100,000 by the end of the century. By contrast, Ireland’s will go down slightly, by 15 per 100,000 people.

In general, wealthier countries in western Europe fare better than eastern Europe, Masselot said.

Several heat waves have killed thousands of people in the last few years in Europe, but one in 2003 is the biggest with about 70,000 deaths.

Big cities with lots of people near the Mediterranean can see the death toll rise through the rest of the century. In the worst-case scenario, the study found that Barcelona could see nearly a quarter of a million extra temperature-related deaths, while Rome and Naples get close to 150,000 each.

In a scenario with carbon pollution only slightly worse than current trends and no extra adaptation to heat, Masselot’s team found more than 5.8 million excess heat deaths just from climate change, along with nearly 3.5 million fewer cold deaths. The team has published an interactive website where cities and different factors can be adjusted.

Masselot’s team was also able to isolate the impact of climate change after adjusting for a major factor of an aging population, which made the study even more useful and impressive, said University of Washington public health and climate scientist Kristie Ebi, who wasn’t part of the study.

“This very much lines up with what we would expect,” said Dr. Courtney Howard, a Canadian emergency room physician and vice chair of the Global Climate and Health Alliance, who was not part of the study. “When you think about summertime daytime temperatures in places like Rome—they start to get up into the 40s (Celsius)…. That’s very much heat stress/heat stroke territory for healthy young people and very dangerous for older people, particularly if they don’t have air conditioning.”

With an older housing stock and not much air conditioning, Europe needs massive amount of adaptation, such as central air, more green space, and cooling centres, to lower the projected death rates, Masselot said. North America is less likely to see such a strong trend, he said.

Another factor is the aging of Europe, which makes its population more vulnerable, he added.

This Associated Press story was republished by The Canadian Press on Jan. 27, 2025.

Cover photo: Jeremy Bezanger/Unsplash