Record-breaking heatwave virtually impossible 50 years ago, scientists warn

Emily Beament, Press Association Environment Correspondent

The June heatwave gripping the UK and Europe would have been virtually impossible in 1976, with climate change fuelling extreme heat, analysis shows.

A rapid assessment of the extremely hot and humid conditions over much of north, western and central Europe found it was the most severe heatwave ever recorded across the region.

The UK has seen temperatures break June records dating back to the infamous summer of 1976, while France has recorded its hottest day ever and temperatures have soared elsewhere in Europe, with widespread disruption and pressure on people’s health.

The analysis found both the daytime highs and overnight temperatures seen during the current heatwave would be virtually impossible at this time of year under the climate of 50 years ago.

A similar heatwave occurring in the climate of 1976 would be 3.5C cooler, the scientists from the World Weather Attribution group said.

The scientists also said the sweltering overnight temperatures keeping many people awake are about 100 times more likely today than they were just 23 years ago during the deadly 2003 European heatwave, and the daytime peaks are about 10 times more likely.

The humidity seen in the current heatwave is a growing danger, they warned, with nearly half (45%) of 854 cities across 30 European countries breaking or expected in late June to break their “wet bulb globe temperature” record – a measure of heat stress and the body’s ability to cool itself through sweating.

For the UK and Ireland, heat stress records were broken in more than half the cities in the analysis.

The heat is being driven by a blocked high-pressure pattern known as a heat dome, that traps hot air over Europe and draws up warm air from the Sahara.

The scientists used observed and forecast temperature data to analyse the hottest three-day period across a swathe of Europe under the heat dome and compared it with similar extreme periods in a cooler climate.

They found the record-breaking heat was unequivocally driven by climate change.

Dr Theodore Keeping, extreme weather and wildfire researcher at Imperial College London, said: “The science of how climate change is worsening heatwaves is settled.

“Continued fossil fuel emissions are directly responsible for the disruption people are experiencing this week in their homes, schools and workplaces.”

He added: “The speed of change is startling. Every few years we are seeing heat records shattered in Europe. This year it has been in consecutive months.

“In the UK, we are used to ‘snow days’ shutting down schools, but this generation is now growing up with ‘heat days’ as well.”

Professor Friederike Otto, professor of climate science at Imperial College London, said: “Scientists like me are beginning to sound like a broken record.

“We put out similar quotes year after year reacting to heat extremes that climb ever higher.

“Yes this is climate change, yes it’s us, no it’s not El Nino, yes we have the solutions, no we’re not implementing them fast enough.

“It’s really now a question of what kind of future we want for ourselves, and whether we’re willing to do what it takes to secure it.”

Responding to the research, UN climate change executive secretary Simon Stiell said: “Extreme heat is shattering records across Europe, and the science is very clear about why: climate change is running rampant, caused by the world’s addiction to burning coal, oil and gas.

“But the solutions are equally clear: a faster shift to clean energy – which is now much cheaper than fossil fuels – as well as protecting forests and building climate resilience.”

He warned that no nation could afford more business as usual, and urged: “We must step up the pace, together.”