Summer temperatures in London could be like Nice in 50 years’ time if carbon emissions continue to rise at their current rate, the Met Office has warned.
Jeff Knight, who runs the forecaster’s climate variability modelling team, said that – in a high emissions scenario – “the central estimate of temperature increase by 2070 is about 4C in southern England.
Referring to the UK’s record-breaking heatwave in 2022, he said: “Despite the events of July last year, 40C days are still considered rare, but by … 2070 then we could be thinking about those kinds of temperatures occurring every five years.
“If we think about a four-degree temperature increase, that would be like transforming the climate of London, the summer temperatures of London, into something like historically we might have seen in Nice.”
But he warned that the UK will continue to see a lot more variability than typical Mediterranean climates, highlighting that the number of intense rainfall events is predicted to increase as temperatures rise due to climate change.
Speaking at a Met Office briefing ahead of the peak summer months, head of situational awareness Will Lang said that he could not rule out a repeat of last year’s heatwave that saw temperatures reach 40C (104F) for the first time in the UK.
He said: “Extremes such as 40C are by definition unlikely but not impossible.”
His comments come after the Met Office published its long-range outlook for June, July and August that suggested the UK has more than double the normal chance of having a hot summer.
He said: “That’s a reasonably standard signal for how much our summers have tended to warm in recent years.
“It does increase the risks of extreme high temperatures, so that’s why I’m not going to rule [40C] out – but at the moment there’s no obvious indication that we’ll see a repeat of last year.”
Scientists are also closely tracking the impact of the arrival of El Nino, a weather pattern that is characterised by warming temperatures on the surface of the Pacific Ocean.
The effects of El Nino can be extremely varied – but the last time it occurred in 2015 and 2016 there was drought in the Caribbean and across the Amazon region, crop failure in southern and eastern Africa, and a punishing dry season in Australia.
Mr Knight said: “At the moment our modelling is kind of suggesting that there is indeed a possibility it could be a near-record event and that is definitely within the envelope of possibility.
“But there are also other projections that suggest it might not be as strong as that – it’s still very early.”
He said that the impact of El Nino on the UK is not easy to predict but that “in general El Nino events tend to lead to milder and wetter starts to the winter and then perhaps colder and drier ends to winter”.