Europe is experiencing its most severe heatwave on record, an oppressive force that has shattered national temperature records, overwhelmed critical infrastructure and reignited questions about whether the continent has learned anything from its devastating past. Across France, the UK, Switzerland and beyond, schools have sent children home early, hospitals have declared critical incidents as cooling units fail and IT systems stall, and wildfires have broken out in tinder-dry landscapes. In France alone, more than 55 people have drowned while trying to cool down, four young children have died inside hot cars, and two nuclear reactors have been forced to close for lack of cooling water. For Pierre Masselot, an environmental epidemiologist at the London School of Hygiene & Tropical Medicine who has become one of Europe’s leading detectives tallying the hidden death toll from heatwaves, the past few days have felt painfully familiar. On Wednesday he received a text from his daughter’s nursery — less than 50 miles from the weather station that first broke the UK June temperature record this week — asking parents to collect their children early because the school buildings were about to become dangerously hot.
France has experienced its hottest day and night on record; the UK and Switzerland have each broken their June temperature records. The heatwave, made hotter by carbon pollution and less bearable by repeated failures to prepare, would have been “virtually impossible” at this time of year just 50 years ago, according to a rapid attribution study published on Friday by World Weather Attribution (WWA). The scientists found that the sweltering overnight temperatures reached this week were about 100 times more likely than in the comparable heatwave of 2003, while daytime peaks were about 10 times more likely. They ruled out any influence from El Niño, the natural warming weather pattern that recently formed in the Pacific and is expected to peak toward the end of the year, likely making 2027 the hottest on record globally. “Every heat wave in the world is now made stronger and more likely to happen by climate change, caused by burning oil, gas and coal, and deforestation,” said Friederike Otto, a climate scientist at Imperial College London and co-author of the study. Europe is warming faster than any other continent, the result of local weather patterns and proximity to the rapidly melting Arctic. The urban heat island effect is making cities especially vulnerable: in places such as Málaga, Genoa and Athens, nearly all residents are affected by pronounced temperature differences between built-up areas and the countryside. Studies indicate that more than 4% of summer mortality in European cities can be attributed to the urban heat island effect, a figure that could be reduced by increasing tree cover.
Lessons from 2003 — and what has changed
The devastation of summer 2003, when an estimated 70,000 people died across Europe — the bulk of them older people, particularly women and those who lived alone — triggered the first serious attempts to deal with extreme heat. Governments linked early warning systems to rapid response measures such as limiting travel, closing schools and cancelling non-urgent hospital appointments when temperatures rose. Research has found that those adaptations proved successful: mortality rates are now far less sensitive to shifts in temperature, and a study published in November found that if the 2003 heatwave were to strike today with the same strength, the projected death toll would be 75% lower. Yet the exceptions of the past have become the norms of today, and the exceptions of today will soon be the norms of tomorrow. Masselot, now 37, was a teenager in southern France when the 2003 heatwave hit; he bounced basketballs in the sun at summer camp, too young then to fear for his health but old enough to grasp the horrors it held. “Climate scientists have been saying for a long time we’ll have a lot more 2003s,” he said. “Now it’s become painfully obvious this is the case.” By the time his toddler is 14 — the same age he was in 2003 — global heating will have blown well past the 1.5C target world leaders promised to keep temperature rises to, and punishing extremes will have hit uncharted heights.
Why adaptation efforts may not keep pace with rising heat
Despite the clear gains from early warning systems and rapid response measures, heatwaves are growing hotter, longer and more common — and it is entirely unclear whether efforts to adapt will keep up with the rising concentrations of planet-heating pollution in the atmosphere. The World Health Organization (WHO) estimates that over the past four years, heat has claimed more than 200,000 lives across 32 European countries. Its regional director for Europe, Hans Kluge, called the toll a tragedy “twofold”. “Most of these deaths were entirely preventable,” he said, “and second, this is just the tip of the iceberg, with millions more people being affected physically and mentally.” Kluge made those remarks in Berlin two weeks ago, standing alongside the WHO’s updated guidelines for heat health action plans — the first revision in 18 years. Berlin is now facing 40C heat. The guidelines urge a coordinated, institutional response built around early warning systems, targeted help for vulnerable groups and long-term prevention measures, with the goal of “zero heat-related deaths”. But implementation across Europe remains uneven. Germany adopted a state-wide heat-health action plan with 72 measures only last year, while other countries still lack any formal plan. Even where plans exist, the pace of adaptation is being undermined by political opposition and competing economic priorities.
Right-wing populist parties across Europe have fought efforts to expand clean energy or make homes more energy efficient. In France, Marine Le Pen has called for a “grand plan” for air conditioning — subsidising systems for schools, hospitals and homes — in the same week her party tried to block new wind and solar projects. The debate has erupted again months before presidential elections. Critics, including Jean-Luc Mélenchon, warn that widespread air conditioning exacerbates the urban heat island effect and worsens climate change. The WHO’s own position is nuanced: it deems air conditioning “not a sustainable societal solution” but acknowledges it “remains crucial” for those at increased risk. Polls in France suggest two-thirds of the public view air conditioning as a temporary fix, preferring sustainable investments such as shading, better ventilation and more green space in cities. Overseas, the European aversion to mass air conditioning has been turned into a meme by the US far right. In a post on X boosted by Elon Musk, the world’s richest man, a US tech chief executive shared a screenshot of chatbot-generated text that read: “Europeans should just install air-conditioning” and “the American approach to summer was correct all along.” The post has been viewed 19.5 million times.
Meanwhile, centrist governments across Europe are weakening climate policy and rolling back green rules in the name of competitiveness. The UN secretary-general, António Guterres, who warned at the start of the week that London was “cooking”, repeated his longstanding pleas at London Climate Action Week on Tuesday to stop burning fossil fuels. The next day, organisers of a related panel on extreme heat governance cancelled it — because it was too hot. On Thursday, the US president, Donald Trump, advised the UK’s likely next prime minister, Andy Burnham, to “open up the North Sea” for oil and gas drilling, despite experts saying it is a mature basin with at least 90% of accessible fossil fuels already used. Burnham has expressed openness to expanding North Sea drilling, a stance that has drawn criticism from environmentalists and praise from Trump. The British Chambers of Commerce has urged support for North Sea resources to prevent job losses. Businesses more broadly are advocating for the overhaul of environmental laws, framing them as burdensome and inefficient, contributing to a broader shift away from green transition priorities.
For scientists who have long warned that heatwaves are getting worse as carbon pollution rises, the failure to follow expert advice has become tiring. “There’s a sad inevitability to all of this, with scientists like me trotting out the same quotes year after year,” said Otto. “Yes it’s climate change, yes it’s us, no it’s not El Niño. Simply put, we remain on a one-way trip towards a more dangerous future, and it’s time we hit the brakes.” She added that the more unequal a society is, the more severe the climate disaster — a reality reflected in the disproportionate toll on older people living alone, those in poor housing, and marginalised groups such as migrants and refugees. Heat and health experts have called for more shading to keep heat out of homes, better ventilation to cool them down as they warm, and more green space in cities to counter the urban heat island effect. Hospitals need more support, and citizens should check on neighbours who are old or vulnerable due to illness. Some experts are wary of mass adoption of air conditioning, which heightens the risk of blackouts and worsens the urban heat island effect, but still want it in care homes, hospitals, schools and public transport. For Masselot, whose typical summer as a child involved sitting inside with all the shutters closed — “basically you live in a cave from 10am to 6pm” — there has at least been some progress in awareness of heat and how best to cope with it. “People have learned lessons and now we know the consequences it can have,” he said. “But sometimes it feels as soon as the summer has ended, we forget about it.”