Soaring temperatures likely to hit UK summers

London - Research has found rising temperatures could affect the summer months in the UK over the next 80 years.

Heatwaves of 40°C could occur as often as every 3 and a half years. The highest temperature ever recorded in the UK was on July 25, 2019, when the mercury hit 38.7°C in Cambridge.

New Zealand has already registered record temperatures this year, with Invercargill reaching 32C a few days ago. Hotter days are on their way.

A stark warning about the kind of summer that could become routine in the UK by the end of this century has been issued in a study by the country’s Met Office.

Using temperature data and climate model simulations, the researchers tested the likelihood of UK temperatures exceeding 30°C, 35°C, and 40°C each summer over the next 80 years.

The study found that if global greenhouse gas emissions continue to rise, temperatures exceeding 40°C could be reached somewhere in the UK every three-and-a-half years by 2100.

In England, 2000 people every year already die from heat related illnesses. While traditionally warmer climes have adapted over time to soaring summer temperatures, the UK is not prepared to handle these kinds of heatwaves.

With global warming comes an increase in the frequency and intensity of extreme weather. According to the new study, UK temperatures hotter than 35°C currently occur once every five years. But by 2100, heatwaves of this magnitude are likely to occur every year in the UK.

Between 1960 and 2016, maximum daytime temperatures rose as much as 1°C per decade in the south-east of the UK, whereas temperature changes in Scotland were more variable, with some areas warming slightly and others cooling, according to the new study.

Overall, England, with its more southerly latitude and greater distance from the cooling effects of the North Atlantic was found to be most susceptible to temperature extremes of 30°C and 35°C.

The UK’s future climate could depend a great deal on how global warming influences the atmosphere over the North Atlantic, and in particular, the North Atlantic jet stream. This is a high altitude band of strong winds that follows the boundary between colder and warmer air and controls the trajectories of storms and the location of pressure centres that strongly influence UK weather.

In May 2020, the jet stream slowed, shifted northwards, and buckled, allowing a high pressure centre to stall over the UK (and much of Europe) for weeks. This led to May 2020 being the sunniest month ever recorded in the UK. It was also the warmest May recorded globally.

Rising temperatures in the northern hemisphere, melting Arctic sea ice and greenhouse gas emissions are likely influencing the behaviour of the jet stream. While scientists try to understand the jet stream’s sensitivity to these factors, the UK should brace itself for the inevitable heat of future summers.