The unprecedented heat wave hitting Europe day and night this month would not have been possible without climate change, according to a new study.
World Weather Attribution’s preliminary study released Friday revealed that this heat wave would have been virtually impossible just five decades ago, and that it is 200 times more likely today than it would have been 20 years ago.
Millions of people in France, Italy, Spain, the United Kingdom and other European countries are suffering from extreme temperatures and humidity this week associated with a heat wave. Daytime temperatures have exceeded 40 degrees Celsius (104 Fahrenheit) in many places, while high nighttime temperatures have also made rest and recovery difficult.
1/19 | Europe burns: powerful heat wave affects several countries and breaks temperature records. Several people enjoy a picnic on the banks of the Seine River during a sunny day, Monday, May 25, 2026, in Paris. A spring heat wave continued to hit parts of Western Europe on Tuesday. -Michel Euler
Scientists estimated that a heat wave with similar characteristics, if it had occurred under the climatic conditions of June 1976, would have been about 3.5 degrees Celsius (6.3 Fahrenheit) cooler during the day and about 2 degrees Celsius (3.6 Fahrenheit) colder in 2003. Nighttime temperatures would have been about 2.4 degrees Celsius (4.3 degrees Fahrenheit) lower in June 1976 and about 1.3 degrees Celsius (2.3 degrees Fahrenheit) lower in 2003.
They chose the years 1976 and 2003 for comparison because extreme heat waves were recorded in Europe in those years.
“The rise in temperatures was so dramatic that we would never have expected this phenomenon to occur in the climate of 1976,” said the study’s lead author, Theodore Keeping, also a climate scientist at the Center for Environmental Policy at Imperial College London. “And it would also have been very, very unusual, even 23 years ago, in 2003.”
Climate change is the main cause of the heat wave
World Weather Attribution, a European-based collaborative initiative of scientists studying the causes of global extreme weather events, began in 2015 to assess the extent to which such events could be attributed to climate change caused by the burning of fossil fuels such as coal, oil and gas. The organization’s rapid attribution studies, including this one, are not peer-reviewed, but use methodology that has been peer-reviewed.
The present study used observed and forecast temperature data to analyze the heat wave that began on June 18.
Likewise, it was found that 45% of the 850 cities analyzed in 30 European countries have broken, or are expected to break, records in terms of heat stress levels, an indicator that takes into account both humidity and temperature.
“It’s directly related to the heat stress on the human body and our ability to cool down, and it’s a really good indicator of the health effects we expect this heat wave to have,” Keeping said. Heat and humidity are a dangerous combination for humans.
In short, this is the most intense heat wave ever recorded in this region of Europe and the most intense episode of humid heat, according to WWA researchers.
Europe is especially ill-prepared for these extreme temperatures
Europe is the world’s fastest warming continent, with temperatures rising twice the global average since the 1980s, according to the European Union’s Copernicus Climate Change Service. In an independent study last year, WWA researchers found that there were about 1,500 deaths caused by climate change during the heat wave that hit Europe last summer.
This week, meteorological services across Europe have issued red alerts for heat risk, leading to restrictions on sporting events, schools, public transport and places of interest. Many of these countries lack widespread air conditioning or other infrastructure adapted to warmer climates. France, which has been one of the countries most affected by the heat wave, this week recorded the hottest day in its history and has also reported 40 drowning deaths of people seeking to cool off.
WWA scientists stated that the current El Niño warming cycle did not influence this heat wave.
Europe also recorded record temperatures in May. Generally, Europe does not experience such high temperatures until July and August.
The conclusions of the study released Friday are reasonable, but they could downplay the role of climate change in heat waves, said Michael Mann, a climate scientist at the University of Pennsylvania who was not involved in the research.
“In any case, this latest assessment — and all similar assessments — are, in fact, underestimating the role that climate change plays here,” said Mann, who has separately studied how climate change is increasing heat stress in North America.
Keeping, author of the study, stated that the heat wave that is hitting Europe highlights the need to adapt infrastructure and habits to extreme temperatures.
“We have to assume that they will occur. In the short term, they will only increase in frequency,” Keeping said. “We must also address the cause of climate change. And that cause is none other than carbon emissions from burning fossil fuels.”
Alexa St. John is a climate change journalist for the Associated Press. Follow her on X: @alexa_stjohn. You can contact her at ast.john@ap.org.
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This story was translated from English to Spanish with an artificial intelligence tool and was reviewed by an editor before publication.