Heat will kill more than cold in Europe eventually

For years, scientists figured that with global warming there are fewer overall temperature-related deaths when those from heat waves and cold snaps are combined. The increase in heat wave deaths during hotter spells is more than offset by reduced cold deaths in milder winters.

But a new study in Europe finds that around 2040, the increase in heat deaths will likely outweigh the reduction in cold deaths. The study suggests that by 2070, global warming may cause 15,000 more temperature-related deaths a year in Europe, which has less air conditioning than the United States.

The study released Tuesday by Nature Communications looks only at deaths from heat and cold, not increases from flooding, droughts and storms. It used computer models to analyze the climate under global warming and compares those to death rates in 200 separate regions of Europe.

The study's chief author, Joan Ballester, a climatologist at the Catalan Institute of Climate Sciences in Barcelona, said the same death assumptions cannot be made for other continents.

Jonathan Patz, director of the Global Health Institute at the University of Wisconsin, said there seems to be fewer cold-related deaths in the United States than in Europe. That may mean that America will see heat deaths outweigh cold deaths sooner than Europe does, he said. Other experts say air conditioning in the U.S. is a big factor so that scenario is unlikely.

Overall, the decreases in European temperature-related deaths "are going to be clearly lower than what was expected," Ballester said.

Ballester's calculations show that starting around 2025, Europe will probably have the fewest temperature-related deaths in recent time, about 11,000 a year fewer than now. But then it increases back to current levels and by 2070, total temperature-related deaths will likely be higher.

Some places in Europe will suffer more than others, Ballester calculates. Figures show that southern Europe, especially Italy, will suffer larger increases in heat deaths while overall temperature mortality will continue to fall in northern places like the United Kingdom and parts of Scandinavia.

Patz, who wasn't part of the study, said Ballester's work "is really an essential paper in the field of climate change and health."

More information: Nature Communications: http://www.nature.com/ncomms

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