Scientists say the current European heatwave is the most severe and widespread ever recorded across western Europe and conclude that it would not have occurred without human-caused climate change driven primarily by fossil fuel emissions. According to researchers from the World Weather Attribution (WWA) consortium, rising global temperatures have dramatically increased both the intensity and likelihood of extreme heat events. Their analysis indicates that a comparable heatwave would have been about 2°C cooler in 2003 and approximately 3.5°C cooler in 1976, demonstrating how continued greenhouse gas emissions have amplified summer temperatures over recent decades.
The European heatwave has produced record-breaking temperatures across much of the continent. The United Kingdom recorded its hottest June temperature on record at 36.7°C in Somerset, while many European capital cities experienced their hottest three-day period ever recorded, regardless of the time of year. More than 100 million people were expected to face temperatures exceeding 35°C. Scientists also found that unusually warm nighttime temperatures, which prevent the human body from recovering from daytime heat, are now around 100 times more likely than they were in 2003.
Researchers emphasized that heat-related risks extend beyond air temperature alone. High humidity significantly reduces the body’s ability to cool itself through sweating, increasing dangerous heat stress. Using wet bulb globe temperature measurements, the team found that nearly 45% of Europe’s largest cities experienced their highest levels of combined heat and humidity ever observed. These conditions increase the likelihood of heat exhaustion, heatstroke, cardiovascular complications, and other serious medical emergencies, particularly among older adults, children, and people with underlying health conditions.
The European heatwave has already placed enormous pressure on healthcare systems and public infrastructure. Hospitals have reported increasing medical emergencies, schools have temporarily closed, transportation services have been disrupted, and rail and airline operations have faced cancellations due to extreme temperatures. Previous heat events illustrate the potential consequences. More than 60,000 heat-related deaths were recorded across Europe during the summer of 2022, while a separate study estimated that over 2,300 people died during a smaller heatwave in 2024 across just 12 European cities. Researchers concluded that roughly two-thirds of those deaths would likely not have occurred without climate change.
Scientists determined that natural climate variability, including the developing El Niño event, was not responsible for the current heatwave’s exceptional intensity. Instead, a persistent high-pressure “heat dome” trapped hot air over western Europe while drawing additional warm air northward from the Sahara Desert. Although these weather patterns are not uncommon during summer, researchers found that global warming significantly increased the temperatures experienced during the event.
Experts stress that while investments in early warning systems and emergency response plans since the devastating 2003 heatwave have saved lives, they are no longer sufficient on their own. Continued warming is increasing risks to public health, transportation, energy infrastructure, and economic activity. Scientists and international organizations argue that reducing greenhouse gas emissions, accelerating the transition to clean energy, improving climate resilience, and investing in heat-resistant buildings and infrastructure are essential to reduce the impacts of future events. Without stronger climate action, researchers warn that the current European heatwave may eventually be viewed as relatively moderate compared with the even more intense heat extremes expected in the coming decades.