Heat waves currently happening in North America, Europe 'virtually impossible' without climate change: Report

A new report quantifies the role climate change has had in recent intense heat.

July 25, 2023, 1:01 AM

The dangerous heat waves currently plaguing North America and Europe would be "virtually impossible" without anthropogenic, or human-caused, climate change, according to a new report.

Intense weeks-long heat waves have been continuously breaking heat records on both continents, with no relief in sight. In Europe, prolonged sizzling temperatures are expected in countries like Italy, Spain, France, Germany and Poland, the European Space Agency announced last week. Regions in the U.S. that have been experiencing record-breaking heat, including the Southwest and Southeast, will continue to experience scorching temperatures for the foreseeable future, forecasts show.

The heat waves occurring in Europe, North America and China throughout July would not have been possible without global warming, according to a rapid attribution analysis by World Weather Attribution, an academic collaboration that uses weather observations and climate models to calculate how climate change influences the intensity and likelihood of extreme weather events.

Temperatures have skyrocketed to 45 degrees Celsius -- or 113 degrees Fahrenheit -- in some regions, prompting heat alerts, wildfires and heat-related hospital admissions and deaths, the researchers said.

Phoenix Zoo senior keeper Ron Pohl sprays cooling water on Elvis, a Galapagos tortoise to offer some relief from a record-breaking heatwave in central Arizona, July 18, 2023.
The Arizona Republic via USA Today Network

The recent heat waves are no longer considered "unusual," as the continued warming from greenhouse gas emissions will cause future heat waves to be even hotter unless emissions are drastically cut, according to the report.

Climate change has made heatwaves hotter, longer and more frequent, evidence shows. The researchers studied the periods of most dangerous heat in each of the regions, and found that these heat waves are no longer rare due to warming caused by burning fossils and other human activities, the report found.

The study also found that climate change made the current heatwave in China at least 50 times more likely and that current temperatures in Europe and North America would not have been impossible without the effects of burning coal, oil and gas, deforestation and other human activities.

Temperatures in Europe have measured about 2.5 degrees Celsius -- or 36.5 degrees Fahrenheit -- more than normal, while the heat wave in North America was about 2 degrees Celsius -- or 35.6 degrees Fahrenheit -- higher, the analysis found. China was also at 1 degree Celsius -- or 33.8 degrees Fahrenheit -- higher, according to the report.

Tourists cool off at a fountain in Rome, July 22, 2023, as an intense heat wave reached Italy and much of Europe.
Andrew Medichini/AP

Events like these now have a 10% chance of occurring any given year in Europe and about a 6.7% chance of occurring in any given year in the U.S., the analysis found. Without human-induced climate change, extreme heat would likely be limited to just once every 250 years, while heat waves of the magnitude of what has been experienced in July would have been virtually impossible.

Because these heat events are expected to become more frequent, the need for humans to adapt and increase greenhouse gas mitigation efforts is vital, the researchers said.

"Our adaptation to that rapid change hasn't occurred fast enough that we are able to see them as common events at this point," Julie Arrighi, manager of the Red Cross Red Crescent Climate Centre in The Netherlands, told reporters during a news conference on Monday. "And so it underscores the need for our systems to adapt much faster, because the risks are rising faster than we are adapting."

If global temperatures reach a 2-degree Celsius rise in temperatures since the 1800s, the heat waves will become even more frequent and extreme and occur every two to five years, according to the report. Temperatures have already risen about 1.2 Celsius since the late 1800s, according to climate scientists.

"In the past, these events would have been extremely rare," Friederike Otto, senior lecturer in climate science at the Grantham Institute for Climate Change and the Environment at Imperial College London, told reporters in a news conference on Monday. "So it would have been basically impossible that they would happen at the same time."

PHOTO: Tourist work with local residents try to extinguish a fire, near the seaside resort of Lindos, on the Aegean Sea island of Rhodes, southeastern Greece, July 24, 2023.
Tourist work with local residents try to extinguish a fire, near the seaside resort of Lindos, on the Aegean Sea island of Rhodes, southeastern Greece, July 24, 2023. A weeklong wildfire forced more evacuations as fires raged fueled by strong winds and successive heat waves that left scrubland and forests tinder-dry.
Petros Giannakouris/AP

It is unclear how long the record-smashing temperatures will last, as the accuracy for forecasts decreases after a week. While the El Nino event is likely contributing somewhat to the additional heat, increased global temperatures from burning fossil fuels is the main reason the heatwaves are so severe, the researchers said.

However, the heat waves are not evidence of "runaway warming" or climate collapse, Otto said, adding that there is still time to move the needle on greenhouse gas mitigation.

"We still have time to secure a safe and healthy future, but we urgently need to stop burning fossil fuels and invest in decreasing vulnerability," Otto said. "If we do not, tens of thousands of people will keep dying from heat-related causes each year."

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