Temperatures of 40C in the UK would be “virtually impossible” without climate change, scientists have said as temperatures climbed to record levels.

London Heathrow became the first place in the UK to ever record a temperature above 40C, reporting a provisional 40.2C at 12.50pm on Tuesday.

Met Office chief scientist Professor Stephen Belcher said: “I wasn’t expecting to see this in my career, but the UK has just exceeded 40C for the first time.”

He added: “For me it’s a real reminder that the climate has changed and will continue to change.”

He said Met Office research had showed that “it’s virtually impossible for the UK to experience 40C in an undisrupted climate, but climate change driven by greenhouse gases has made these extreme temperatures possible, and we’re actually seeing this possibility now.”

A recent Met Office study found that summers which see days above 40C are still very rare – although the risk of them is increasing – but they could occur as often as every three or four years by the end of the century if emission remain high.

Even with current pledges to cut emissions, 40C summers could occur every 15 years by 2100, the research found.

Prof Belcher said: “We are already committed to a level of warming and these extremes will get more extreme in the future.

“The only way we can stabilise the climate is by achieving net zero, and of course the UK has made some great strides in that direction.”

But he added: “We want to stabilise the climate at a safe level and that means reaching net zero soon.”

Climate change, as a result of human activities such as burning fossil fuels that put heat-trapping greenhouse gases into the atmosphere, has pushed up global and regional temperatures and made some areas drier, making heatwaves more intense, frequent and likely.

Dr Friederike Otto, from the Grantham Institute for Climate Change, Imperial College London, said: “40C at Heathrow, would have been extremely unlikely or virtually impossible without human caused climate change.

“It’s now an event that shouldn’t have surprised anyone. While still rare, 40C is now a reality of British summers.

“Whether it will become a very common occurrence or remains relatively infrequent is in our hands and is determined by when and at what global mean temperature we reach net zero.”

She also said: “It is also in our hands whether every future heatwave will continue to be extremely deadly and disruptive.

“We have the agency to make us less vulnerable and redesign our cities, homes, schools and hospitals and educate us on how to keep safe.”

Environmental groups responded to the record high temperatures by calling for candidates for the Tory leadership, who will be the next prime minister – to prioritise action on climate change.

The remaining Conservative leadership contenders have committed to meeting net zero by 2050, but have been criticised for not focusing on it in the contest.

Mike Childs, head of science, policy and research at Friends of the Earth, said: “Candidates vying for Conservative Party leadership cannot ignore the vital importance of curbing the climate and nature crises.

“We need climate action that goes further, and faster, so that the next generation has a world left to inherit.”

Greenpeace UK’s head of politics, Rebecca Newsom, said: “It’s clear to everyone that urgent action to cut emissions must be taken, but the four Tory candidates are staying conspicuously quiet on the matter.

“This life-threatening heat is just a taster of what’s to come unless the next Prime Minister delivers the concrete policies that will transition the UK away from fossil fuels, cut bills, boost cheap renewables and green our homes.

“Failure to do so won’t just lose the Conservatives votes at the next election – it will threaten the future of our society as we know it.”