The intense heatwave sweeping across Europe this month, pushing daytime temperatures above 40 degrees Celsius in multiple countries, owes its severity largely to human-driven climate change, according to a new rapid study from World Weather Attribution. The organization found that such extreme heat would have been almost impossible five decades ago and is now dramatically more likely than just two decades ago.
Scientists compared recent conditions with those of historic heatwaves in 1976 and 2003, years previously marked by intense heat in Europe. They discovered that today’s heatwave registers temperatures several degrees higher than similar events in the past. Daytime temperatures would have been about 3.5 degrees Celsius cooler than current levels if the heat occurred under 1976 climate conditions, and about 2 degrees cooler than in 2003. Nighttime temperatures, important for relief and recovery from daytime heat, were also significantly lower in the past—by around 2.4 degrees Celsius compared to now.
This increase in temperatures underscores how climate change has shifted the baseline, making extreme heatwaves more severe and frequent. The study’s lead scientist pointed out that the current heatwave's intensity would have been extraordinarily rare, if not impossible, in the 1970s and still highly unusual in the early 2000s.
World Weather Attribution is a network of scientists based in Europe that employs a rapid assessment method to determine the influence of climate change on extreme weather events worldwide. While these rapid studies are not peer-reviewed, they use established, peer-reviewed scientific methods. Their latest analysis included temperature observations and forecasts, focusing on a heat dome that has kept much of Europe under sustained high heat and humidity.
The organization’s data highlights that nearly half of the 850 cities analyzed across 30 European countries have already set or are on track to set new records for heat stress levels—a measure combining heat and humidity that directly impacts human health. Such conditions elevate risks for heat-related illnesses and complicate efforts to cool down during warm nights.
The study reinforces the established link between the burning of fossil fuels and the escalating frequency and intensity of extreme heat events. As global temperatures rise, heatwaves like the current episode are becoming increasingly commonplace, posing growing challenges for populations and infrastructure across Europe.