Man-made climate change made last week’s record-breaking heat wave at least 10 times bigger, according to a study by a team of international scientists.
scientists also warned that extreme temperatures in the UK were higher than climate models predict – suggesting that the impact of climate change on heat waves could be even worse than previously thought.
The 10-fold increase in the likelihood of such extreme heat in the UK due to climate change is a conservative estimate, the researchers from the World Weather Attribution initiative said.
And while the scorching heat, which saw temperatures soar above 40°C for the first time in the UK, is still a very rare occurrence in the current climate, it would be “almost impossible” without global warming.
Mariam Zachariah, of the Grantham Institute for Climate Change, Imperial College Londonsaid: “Even with a conservative estimate, we see a large role of climate change in the heat wave in the UK.
“In our current climate, which has been altered by greenhouse gas emissions, many people experience events in their lifetime that would otherwise have been nearly impossible.”
Much of the UK was suffocated by the heat wave, with a new record temperature for the country of 40.3C in Coningsby, Lincolnshire1.6C hotter than the previous record set just three years ago.
The heat caused widespread disruption to transport networks and hundreds of fires, including devastating fires that destroyed homes, drove London to the brink of power outages and is expected to have caused hundreds of deaths.
The study looked at annual maximum temperatures for two days in the England and East Wales region, where the Met Office had first issued a red warning of extreme heat for July 18-19.
It also examined the change in frequency and intensity of maximum daily temperature observed at three sites: St James’s Park in London, Cranwell in Lincolnshire, close to Coningsby, and Durhamwhere temperatures broke their previous record of 4C.
Researchers used computer modeling to compare the probability of the temperatures observed in the 2022 heat wave under the current climate and in a world without the 1.2 degrees Celsius of global warming since the 19th century.
The modeling suggests that climate change, driven by more heat-trapping greenhouse gases released into the atmosphere by human activity, would have made a heat wave as intense as the one in the UK at least 10 times more likely and probably even more so – although it’s still likely that this only once in 100 years.
In Europe and other parts of the world we are seeing more and more record-breaking heat waves
Fraser Lott, climate monitoring and attribution scientist at the Met Office Hadley Centre, said: “Two years ago, scientists from the UK’s Met Office found that the odds of seeing 40C in the UK were now one in 100 in any given year. , compared to one in 1,000 in the natural climate.
“It was sobering to see such an event happen so soon after that study, to see the raw data coming back from our weather stations.”
But the researchers also warned of extreme heat in the west Europe rising faster than climate models predict.
While the models suggest that climate change caused temperatures to rise 2°C in the heat wave, analysis of historical weather records shows it would have been around 4°C cooler in pre-industrial times, before global warming began to warm the temperatures. to drive up.
Friederike Otto, of the Grantham Institute for Climate Change, Imperial College London, said: “In Europe and other parts of the world, we are seeing more and more record-breaking heat waves causing extreme temperatures that have become hotter faster than in most climate models.
“It is a worrying finding that suggests that if carbon emissions are not reduced soon, the impact of climate change on extreme heat in Europe, which is already extremely deadly, could be even worse than we previously thought.”
Though it will take weeks for figures on the number of additional deaths during the heat wave, estimates have been made that more than 840 people died on July 18 and 19 in England and Wales.
The researchers warn older people, those with chronic health conditions and children who are particularly vulnerable to extreme heat, with urban areas such as London seeing the city retain extra high levels of heat.
There are also significant inequalities exacerbating the situation, with poorer neighborhoods in cities such as London lacking green space, shade and water, which can help people cope with heat waves.
Climate change has increased average global and regional temperatures, meaning natural heat peaks are getting higher and more frequent.
It may also contribute to drier conditions and soils, seen across much of Europe this year, which in turn exacerbate heatwaves because there is less water in the environment to absorb heat as it evaporates.