World Weather Attribution report: Fossil fuel emissions have rapidly worsened European heatwaves in just a few decades.

A study by World Weather Attribution released on Friday (26 June) shows that the heatwave that is currently baking much of Europe is the continent’s worst so far, in terms of heat stress and temperatures, and that the recipe of conditions that created it would have been virtually just 50 years ago. Brought to you by fossil fuels.

Some of the major findings:

• Heatwaves cause more deaths in Europe than all other natural hazards combined
• Vulnerability to heat has shifted over time, from primarily elderly people living alone to populations facing socioeconomic disadvantage and chronic illness, including homeless people and migrants, highlighting the need for adaptive, equity-focused heat-health policies.
• In 1976, when some of the previous European records were set, the 2026 temperatures would have been virtually impossible to occur in June, while also highly unlikely at any time of the year. In 2003, the first major heatwave of this century, daytime heat like this would still have been very rare, about 10 times less likely than today, while nighttime temperatures such as this June would have been more than a hundred times less likely in 2003.
• Across large parts of Western Europe, June is warming faster than any other month. In addition, daily maximum temperatures are warming faster than night time temperatures, though both are warming much faster than global warming. The hottest daily temperatures are warming at about triple the rate of global warming and night time temperatures at about twice the rate. Many capital cities are experiencing not only their hottest June 3-day period but also the hottest three-day period since 1950, according to the ERA5 dataset. However, due to global warming these temperatures are now no longer unusual during the summer months in many capitals.
• This means that a similar heatwave in June would have been about 3.5°C cooler during the day in 1976 and about 2°C cooler in 2003. The nighttime temperatures would have been about 2.4°C cooler in June 1976 and about 1.3°C cooler in June 2003.
• This June 2026 heatwave occurred under a circulation pattern broadly similar to historical analogues – Southerly Flow. However, a similar circulation pattern now produces significantly hotter temperatures than it did in the mid-20th century because the climate baseline has warmed.

And

• This summer shows that at 1.4°C of global warming, extreme heat is already reaching the limits of our societies’ ability to cope. Our analysis here shows that intense heat is increasing rapidly even in living memory, with such events tens to hundreds of times more likely since only 2003 and virtually impossible just 50 years ago. A rapid phase-out of fossil fuels is critical if we are to avoid even higher temperatures and their consequences in the future.

[Report summary] [Full report]