The chances of June temperatures reaching record-breaking levels in western Europe are 10 times more likely than they were than 20 years ago, according to meteorologists.
A team of Met Office scientists used an established rapid attribution methodology to calculate the chances of reaching the record high temperatures of June 2003 in western Europe under the climatic conditions of the time.
The researchers then compared that probability to that of the same temperatures being reached in the current conditions.
They found that, what was a one-in-723-year event in 2003, is now a one-in-66-year event – an alarming discovery that reveals how rapidly the impacts of climate change are imposing themselves on the weather, they said.
The team also calculated that unless action is taken to reduce greenhouse gas emissions globally, heatwaves of the magnitude recorded in 2003 could happen every two to three years by 2100, in a medium emissions scenario.
However, in a natural climate where human greenhouse gas emissions were removed, June temperatures like those seen in 2003 would only be seen once every 8,200 years, according to Met officials.
The study was launched as notably high temperatures for the time of year began to be recorded in western Europe, with France recording its earliest 40C in the year on record.
Met Office climate change attribution scientist, Dr Nikos Christidis, said: “Attribution studies examine the influence of climate change on current events and how they could be more likely in the future, depending on future greenhouse gas emissions.
“Our latest study has looked at how the chances of the hottest June on record in western Europe have changed over the past 20 years.
“We found that in just two decades, the probability of seeing those record breaking 2003 temperatures again have become more than 10 times more likely.
“We also applied our extreme event attribution approach to project how the probabilities might change in the future if we don’t reduce greenhouse gas emissions.
“This showed that the 2003 record breaking June could be witnessed every two to three years by the end of the century.”
Significant heatwaves similar to those in 2003 and June 2022 can have severe knock-on affects on human health, infrastructure and food production.
The Met Office pointed specifically to high overnight temperatures, which means the body has no opportunity to recover from the daytime heat – exacerbating existing health conditions and causing heat related illness in the usually fit and healthy.
Professor Peter Stott, deputy head of climate science at the Met Office, added: “At the time of the 2003 record breaking June in western Europe I led an attribution study which calculated that human induced climate change would make events like this 100 times more likely over the next 40 years and would become a regular occurrence.
“At the time it was a surprising and shocking conclusion. But 20 years on this new study has confirmed what we were saying back then; the impacts of climate change on our weather are already being seen across the world and those impacts are increasing very rapidly.”