British summers are likely to regularly see temperatures of above 40C even if humanity manages to limit global warming to 1.5C, the UK’s leading meteorologists have warned.

The UK is already seeing increasingly extreme weather, with 2020 the third warmest, fifth wettest and eighth sunniest year on record- the first ever to fall into the top 10 for all three variables.

Data published in the report The State Of The UK Climate 2020 revealed the average winter temperature for last year was 5.3C – 1.6C higher than the 1981 to 2010 average.

The fifth warmest winter on record was December 2019 to February 2020, while the temperature last summer was 0.4C above average at 14.8C. 

The Herald:

Early August 2020 saw temperatures hit 34C on six consecutive days, with five “tropical nights” where the mercury did not drop below 20C, making it one of the most significant heatwaves to affect southern England in the past 60 years, the report’s authors said.

Comparing data from the Central England Temperature series, which dates back to 1772, the research found the early 21st century has been 0.5C to 1C warmer than 1901 to 2000 and 0.5 to 1.5C warmer than 1801 to 1900. 

Chief executive of the Royal Meteorological Society, Professor Liz Bentley, said the world was already seeing extreme heat as a result of warming of 1.1C to 1.2C above pre-industrial levels. 

“If you take that up by another 0.3C, these (heatwaves) are just going to become much more intense – we’re likely to see 40C in the UK although we have never seen those kinds of temperatures (before),” she said.

“As we hit 1.5C of global warming, that’s going to not just become something that we see once or twice, it’ll start to become something that we see on a much more regular basis.”

Mike Kendon, climate scientist at the Met Office and lead author of the report, said the figures indicated a new normal for the UK.

“In seven out of the last 10 years, we’ve seen temperatures of 34C in the UK compared to seven out of the previous 50 years before that,” he said.

“So, this is an indication of the fact that our baseline of our climate is changing and what we regard as normal is changing.”

Mr Kendon warned man-made global warming will last “for a very, very long time to come”, adding scientists at the Met Office’s National Climate Information Centre had been “blown away” by the extreme heat of 49.6C seen on the west coast of Canada in recent weeks.