But the World Weather Attribution Project, which carried out the analysis, also said its findings are likely to be an underestimate, warning that the tools available to scientists have limitations and are creating a blind spot about the role that humans play in heat waves.
Heat waves are becoming more frequent and longer globally, and scientists say human-caused climate change is influencing them all.
To determine the human influence on extreme heat, scientists use a combination of observations and climate models, or simulations. Although the models tend to be conservative in their findings, the observed extreme heat in Western Europe increased much more than the models estimated.
“While models estimate that greenhouse gas emissions increased temperatures in this heat wave by 2°C, historical weather records indicate that the heat wave would have been 4°C cooler in a world that had not been warmed by human activities,” WWA said in a press release. . “This suggests that the models are underestimating the real impact of human-caused climate change on high temperatures in the UK and other parts of western Europe. It also means that the results of the analysis are conservative and that the Climate change likely increased the frequency of the event by more than a factor of 10 as estimated by the study.”
Last week, the UK experienced high temperatures that rose above 40 degrees Celsius (104.5 degrees Fahrenheit) for the first time on July 19, reaching 40.3 degrees Celsius in the English village of Coningsby. The British government issued its first red-level extreme heat warning for several parts of England, including the capital, London. As temperatures rose, the country’s infrastructure broke down. Train tracks bent out of shape; an airport runway melted; London’s fire service declared a “major incident” as several fires broke out, in what the service said were its busiest days since the Second World War.
People were advised to work from home, some schools were closed, while hospitals and emergency services were stretched to the limit.
“In Europe and other parts of the world we are seeing more and more record heat waves causing extreme temperatures that have become warmer faster than in most climate models,” said Friederike Otto of the Grantham Institute for the Climate Change at Imperial College London, which leads the WWA project. “It is a worrying finding that suggests that if carbon emissions are not reduced quickly, the consequences of climate change on the already extremely deadly extreme heat in Europe could be even worse than previously thought.”
Every fraction of a degree of global warming will lead to a worsening of the impacts of the climate crisis. The world has already warmed by about 1.2 degrees Celsius on average, and there is a growing consensus that humans must try to keep warming to 1.5 degrees to avoid tipping points, where some ecosystems on which the Earth depends for its ecological balance may struggle to recover.
Scientists said the model results also indicated that a heatwave as intense as last week’s in the UK is “still rare in today’s climate”, with a 1% chance of happening each year . However, once again, weather records suggest that the computer simulation results are conservative, and similar extreme heat events are also likely to occur more frequently.
Responding to the publication of the new WWA analysis, Dr Radhika Khosla of the Oxford Smith School of Enterprise and the Environment praised the scientists for their speed.
“By conducting rapid analysis based on established, peer-reviewed methods, the WWA team is able to get evidence-based results into the public domain while we can all remember the major disruptions of extreme heat in the last week. This is the latest in a series of studies that all show the same result: climate change is making heat waves more likely and more intense,” Khosla said.
“The level of heat the UK is now experiencing is dangerous – it puts stress on our infrastructure, economy, food and education systems and our bodies. As the study points out, many UK homes become uninhabitable in a heat extreme. Adaptation. to rising temperatures, building resilience to heat with sustainable approaches and protecting people is an urgent priority as unprecedented temperatures become the norm.”
Peter Stott, a climate attribution scientist at the UK Met Office, said this would not be the last time the country would be forced to deal with such extremes.
“Temperatures above 40C will occur again, possibly in the coming years and most likely in the coming decades,” Stott said. “Only by reducing greenhouse gas emissions will we be able to reduce the risks of these extremes becoming more and more frequent.”
CNN’s Angela Dewan and Rachel Ramirez contributed to this report.