Key facts
- Europe's current extreme heatwave is directly linked to human-caused climate change.
- The heatwave would have been virtually impossible without climate change, and is 200 times more likely today than 20 years ago.
- Daytime temperatures have exceeded 40 degrees Celsius (104 Fahrenheit) in many European locations.
- 45% of analyzed cities in 30 European countries are expected to break heat stress records.
- Europe is warming at twice the global average rate since the 1980s.
Europe's current extreme heatwave, which has seen temperatures exceed 40 degrees Celsius (104 Fahrenheit) in many areas, would have been virtually impossible without climate change, according to a new rapid attribution study by World Weather Attribution (WWA).
The study found that the heatwave is 200 times more likely today than it was 20 years ago. Scientists compared the current conditions to heatwaves in June 1976 and 2003, estimating that a similar event in 1976 would have been about 3.5 degrees Celsius (6.3 Fahrenheit) cooler during the day and 2.4 degrees Celsius (4.3 Fahrenheit) cooler at night. In 2003, the event would have been approximately 2 degrees Celsius (3.6 Fahrenheit) cooler during the day and 1.3 degrees Celsius (2.3 Fahrenheit) cooler at night.
Lead author Theodore Keeping, a climate scientist at Imperial College London, stated that the increase in temperatures was so dramatic that the event would have been unexpected even in 1976 and still very rare in 2003. The WWA, which has been assessing the link between extreme weather and climate change since 2015, noted that the current study used observed temperature data and forecasts for the heatwave that began on June 18.
The analysis also revealed that 45% of 850 cities across 30 European countries have broken or are expected to break records for heat stress levels, a metric that combines temperature and humidity to indicate health impacts. Researchers described the current event as the most severe heat wave and humid heat event ever recorded in this region.
Europe is warming at twice the global average rate since the 1980s. A previous WWA study estimated around 1,500 climate change-related deaths during a European heatwave last summer. Weather agencies have issued red alerts, leading to limitations on events and services, as many European countries lack widespread air conditioning. France, which has experienced its hottest day on record, has also reported 40 deaths from drownings as people sought relief from the heat. The WWA scientists confirmed that the El Nino warming cycle did not influence this heatwave.
Michael Mann, a climate scientist at the University of Pennsylvania not involved in the research, suggested that such assessments might underestimate climate change's role. Keeping emphasized the need to adapt infrastructure and behavior to more frequent extreme temperatures and to address the root cause: carbon emissions from burning fossil fuels.