Leading climate scientists have called on Theresa May to swiftly put a target to cut greenhouse gas emissions to zero into national law.
A group of experts have written to the Prime Minister urging her to enshrine a net zero target in law as a act of global leadership and a "worthy legacy" of her premiership.
The call comes after the Government's climate advisers urged ministers to set a new legal target for a 100% cut in all greenhouse gases by mid-century as soon as possible, and to urgently ramp up efforts to cut emissions.
Under the net zero target, emissions would have to be largely eliminated from electricity generation, transport and heating, the Committee on Climate Change said.
Any remaining pollution by 2050 from areas including aviation would need to be offset through measures to capture carbon such as planting trees.
The move to net zero would be in line with commitments to limit global temperature rises to 1.5C above pre-industrial levels under the international Paris Agreement, and would provide leadership for other countries on tackling climate change, the committee said.
In their letter to Mrs May - who has announced her resignation - the experts said the science was "unequivocal" that avoiding dangerous climate change means not just reducing carbon emissions but bringing them to net zero.
They pointed to the committee's advice that a new net zero target could quickly be brought in through a statutory instrument amending the UK's existing legal goal to cut greenhouse gases by 80% by 2050.
They wrote: "To do so now would be to make a powerful statement of global leadership on climate change worthy of the tradition established by Mrs (Margaret) Thatcher 30 years ago when she became the first leader of a major nation to call for a United Nations climate change treaty.
"A net zero target is what science concludes is necessary to meet the Paris targets, and to set one in law swiftly, in line with the expert advice commissioned by your Government, is within your gift.
"To do so would be an act of global importance for future generations, and a worthy legacy."
The letter's signatories include emeritus professor Joanna Haigh from Imperial College London, Myles Allen from Oxford University, Sir Brian Hoskins, who chairs the Grantham Institute on Climate Change, and Professor Dame Julia Slingo.
Prof Haigh said it was a question of seizing the day.
"It's such an important topic, we've all the scientific indicators that show something needs to be done, and it's in the Conservative Party tradition going back to Margaret Thatcher."
She said it could be an achievement of Mrs May's premiership which would be great for the UK and set an example for the rest of the world.
A Government spokesman said: "We already lead the world in tackling climate change, being the first country to introduce long-term legally-binding carbon reduction targets and cutting emissions further than all other G20 countries.
"The Committee on Climate Change's report now sets us on a path to become the first major economy to legislate to end our contribution to global warming entirely and we will respond in a timeframe which reflects the urgency of the issue."