Scorching Summers in Store for Mediterranean

If carbon dioxide emissions continue to increase, summer days will got hotter around the Mediterranean. Credit: Purdue University

The number of extreme hot events increases even if carbon dioxide emissions are curbed. Credit: Purdue University

Scorching heat could spell more dangerous summers for the Mediterranean over the next 100 years, a new analysis finds.

A 2003 heat wave took 15,000 lives in France and 3,000 in Italy as temperatures soared over 100 degrees Fahrenheit, but if greenhouse gases continue to build up in the atmosphere at their present rate, temperature rises could dwarf those in Europe during that summer.

“Rare events today, like the 2003 heat wave in Europe, become much more common as greenhouse gas concentrations increase,” said study team leader Noah Diffenbaugh of Purdue University in Indiana.

In a simulation using emissions scenarios from the Intergovernmental Panel on Climate Change, sweltering temperatures “become the norm and the extreme events of the future are unprecedented in their severity,” he added.

The analysis, funded by the National Science Foundation and others, indicated that daily temperatures currently found in Europe’s hottest two weeks of the summer will become the normal temperatures for the coldest two weeks. In Paris, for examples, the temperatures during the 2003 heat wave are exceeded more than two dozen times every year in the study’s projections of the future.

Reduced precipitation could make the Mediterranean’s hottest days even hotter: as the land surface warms, it gets drier, and dry soil means less moisture in the area in general and less cooling from the evaporation of water.

The study is detailed in the June 15 issue of the journal Geophysical Research Letters.

Even in simulations where emissions of greenhouse gases are tempered, Europe ends up roasting.

“We see negative effects even with reduced emissions,” Diffenbaugh said.

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