Scientists link Europe heat wave to human-caused global warming

The heat wave that smashed temperature records in western Europe last month was made more intense by human-caused climate change, according to a study published Friday.

Similar temperatures would happen once in 1,000 years without climate change, study finds

A woman cools off at a fountain in downtown Rome as a heatwave hit Italy in June. (Yara Nardi/Reuters)

The heat wave that smashed temperature records in western Europe last month was made more intense by human-caused climate change, according to a study published Friday.

The rapid study by a respected team of European scientists points to an array of evidence that man-made global warming was behind the continent's most recent heat wave.

"The July 2019 heat wave was so extreme over continental Western Europe that the observed magnitudes would have been extremely unlikely without climate change," the study concluded.

In countries where millions of people sweltered through the heat wave, temperatures would have been 1.5 to 3 C lower in a world without human-induced climate change, the study said.

Global warming is also making such extreme heat more frequent, the study by experts from France, the Netherlands, Britain, Switzerland and Germany found.

A temporarily dried river bed of the Rhine river in Duesseldorf, Germany, 26 July 2019. The water levels in the rivers are falling sharply. Germany experiences a heat wave with temperatures up to 42 degrees Celsius. (Freidemann Vogel/EPA-EFE)

The scientists said that the temperatures recorded in France and the Netherlands could happen every 50 to 150 years in the world's current climate. Without "human influence on climate," the temperatures would likely happen less than once in 1,000 years.

3 C hotter by 2050

The report's lead author, Robert Vautard of the Institut Pierre-Simon Laplace in France, said Europe needs to get used to such heat waves, which are likely to become more frequent and intense.

"This will go up and if we don't do anything about climate change, about emissions, these heat waves, which today have an amplitude of 42 degrees, they will have three degrees more in 2050, so that is going to make 45 [degrees], roughly speaking," he told The Associated Press.

"What will be the impacts on agriculture? What will be the impacts on water?" Vautard said. He said it will increase "tension in society that we may not be so well equipped to cope with."

While the heat wave broke in western Europe after a few days late last month, the extreme temperatures have since shifted north and are causing massive ice melts in Greenland and the Arctic.

The scientists calculated the odds of this type of heat occurring now and how often it would have happened in a world without man-made global warming and compared them. They created the simulations by using eight different sets of complex computer models.

The U.S. National Academy of Sciences in 2016 studied this new scientific method of climate attribution and pronounced it valid.

In this image taken on Aug. 1, large rivers of melting water form on an ice sheet in western Greenland and drain into moulin holes that empty into the ocean from underneath the ice. (Caspar Haarløv/Into the Ice via Associated Press)

Kathie Dello, a climate scientist from NC State University in North Carolina, said the study helps to pin the blame for the heat wave on climate change.

"If searching for a culprit for the intensity of these recent European heat waves, climate change is the obvious culprit," Dello said in an email. "Attribution is just dusting for fingerprints. Climate change will continue to be a menace when it comes to extreme heat, making these events more likely and more intense."

Another expert not connected to the study, Celine Bonfils of the Lawrence Livermore National Laboratory in California, said the findings are clear: "Record hot weather events are becoming more likely, and human-induced climate change is causing this increase in heat wave frequency."

The new report agreed with their assessments, saying that every recent European heat wave that has been analyzed "was found to be made much more likely and more intense due to human-induced climate change."

Add some “good” to your morning and evening.

A variety of newsletters you'll love, delivered straight to you.

Sign up now


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.

Become a CBC Member

Join the conversation  Create account

Already have an account?