Hundreds of climate change experts have urged Theresa May to confront Donald Trump over his approach to the emergency during his state visit.

As the US president arrived in the UK, the letter signed by 250 scientists and other academics states his “refusal” to tackle global warming is “increasing risks for lives and livelihoods” worldwide.

The experts from UK universities and research bodies praise the UK’s international role in tackling climate change but say Mr Trump’s visit is incompatible with it while he is undermining US and international efforts to reduce greenhouse gas emissions.

It reads: “The president’s refusal to tackle climate change, and particularly his initiation of the withdrawal of the United States from the Paris Agreement, is increasing risks for lives and livelihoods in the United States, the United Kingdom and around the world.”

They urge the prime minister to tell Mr Trump to accept the scientific evidence of the threat of man-made climate change; support policies in the US to reduce greenhouse gases to zero by 2050 and collaborate with international efforts to combat climate change.

Penguin habitats threatened by climate change Show all 9 1 /9 Penguin habitats threatened by climate change Penguin habitats threatened by climate change Gentoo penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins in Cuverville Island, designated as an Important Bird Island. These penguins feed on krill but krill is growing scarcer due to climate change AFP/Getty Penguin habitats threatened by climate change Penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins in Cuverville Island, designated as an Important Bird Island. These penguins feed on krill but krill is growing scarcer due to climate change AFP/Getty Penguin habitats threatened by climate change Chinstrap penguins on King George Island. Global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins in Cuverville Island, designated as an Important Bird Island. These penguins feed on krill but krill is growing scarcer due to climate change AFP/Getty Penguin habitats threatened by climate change A penguin and a seal. Global warming has affected the glaciers that these animals live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty

The president has previously called climate chaos a “Chinese hoax” and “b******t”.

He has been a strong supporter of fossil fuel industries, reversing environmental regulations on oil, gas and coal.

After his own administration last year published a report on the dire effects of climate change compiled by 13 federal agencies, he said he did not believe it.

Then six months ago, his administration held an event promoting the use of fossil fuels at a major UN climate summit.

Scientists on the IPCC have warned the world has just 12 years left to cap global temperature rises at 1.5C, beyond which they would rise exponentially, causing irreversible disaster.

The Paris deal aims to limit rises to 2C, and to strive for 1.5C if possible.

Bob Ward, of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics, who coordinated the letter, said: “President Trump’s refusal to accept and address global climate change is putting at risk lives and livelihoods of current and future generations in the UK.

“The state visit is an opportunity for the prime minister to challenge the president’s reckless approach and advance the UK’s reputation as an international leader on climate change before she steps down as prime minister.

“The special relationship between the UK and USA is meaningless if the government does not use it to confront the actions of a president that are a threat to UK citizens.”