Could 40°C Temperatures Become a Regular Occurrence in the UK?

Temperatures exceeding 40°C could occur in Britain on a regular basis by the end of the century, according to a new study collated by scientists from the Met Office. Their findings showed that unless carbon emissions are cut drastically in the near future, intense heatwaves could become a frequent occurrence in the UK.

At present, highs of 40°C are expected once every few centuries in this country. There has not been such an incident since records began in 1659, with 2019 witnessing the highest ever British temperature of 38.7°C in Cambridge. However, rampant global warming means that heatwaves are already 30 times more likely in the UK than they were before the Industrial Revolution.

Hotter climes ahead

In recent years, our ability to predict periods of dry heat long in advance has come on in leaps and bounds. For the Met Office study, the research team analysed temperatures measurements from across the UK at a scale of one kilometre, then fed that data into 16 different climate simulations. Their aims were to see if we would exceed 40°C – and how regularly – based upon our behaviour.

They found that if emissions were to continue unchecked at their current levels, the 40°C ceiling would be breached once every 3.5 years by the turn of the century. Even under a medium-risk scenario, where emissions are curbed but not enough to prevent a rise in global temperatures of 1.5°C, the UK would experience extreme heat over 40°C once every 15 years.

The team also looked at the potential ramifications for surpassing 35°C on the thermometer. This generally occurs around every five years at present, but would become a fixture annually in either of the aforementioned scenarios. According to their findings, the climate of London would resemble that of Istanbul, Cardiff would be like Montevideo, Leeds similar to Melbourne and Edinburgh more like Paris.

Immediate action needed

In concrete terms, those temperature hikes could have severe ramifications for public health. Recent research found that heatwaves caused almost 900 additional deaths in England last year, while as many as 3,400 lives were lost prematurely due to elevated temperatures across the whole of the UK between 2016 and 2019. In order to prevent such a grim forecast from coming to pass, immediate action must be taken.

That involves a sea change in our daily habits with regard to industry, transport and energy generation. Transitioning to greener sources of power and swapping polluting forms of getting around for environmentally friendly ones could go some way towards achieving greenhouse gas emissions targets for 2020 and beyond, which would have a knock-on effect on temperatures further down the line.

The fact that the UK has already begun weaning itself off fossil fuels is good news, but experts on the subject warn that it may not be enough. “Fortunately, the increasing use of fossil fuels portrayed in [the high-emissions scenario] is unlikely, but the average temperature levels seen at the end of the century under this scenario still remain a real risk if some of the worst-case amplification effects in the Earth system come to pass, such as massive permafrost thawing,” explains Professor Piers Forster, who was not part of the research.