A world-leading climate change target up to the early 2030s is set to be confirmed by the British government.
Ministers are expected to announce that the UK will cut carbon emissions by 57% by 2032, from 1990 levels.
The announcement will help reassure the investors needed to overhaul the UK's ageing energy system.
The energy industry will be relieved after cuts in renewables subsidies and the vote to leave the EU, which influences so much of the UK's energy.
Energy Secretary Amber Rudd said climate change remained one of the most serious long-term risks to the economy.
Speaking at a business and climate summit in London, Ms Rudd said: "Climate change has not been downgraded as a threat.
"We must not turn our back on Europe or the world. So while I think the UK's role in dealing with a warming planet may have been made harder by the decision last Thursday, our commitment to dealing with it has not gone away."
Business spokesmen at the conference echoed a call by the former Labour Climate Secretary Ed Miliband for the prime minister immediately to ratify the Paris climate accord in which nearly 180 countries agreed to cut carbon emissions.
I understand, though, that there will be a warning note from the government's advisers - the Committee on Climate Change. They are expected to press ministers to urgently produce new policies to back up its ambitions.
The committee has previously calculated that the government's targets for low-carbon energy are on track, but said that a new approach is needed on CO2 emissions from housing as well as agriculture and transport - two sectors where emissions are growing.
Committee members have expressed their concern at the government's failure to support carbon capture and storage technology, which will allow fossil fuels to continue to be burned.
The prime minister said it was essential for the UK - before he withdrew the funds supporting the technology.
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