Sir Keir Starmer challenged opposition critics with a promise to double down on net zero as he admitted the “consensus is gone” on climate change in a speech at the UN’s Cop30 summit.
The Prime Minister staunchly defended his Government’s clean energy agenda, but conceded unity on “science that is unequivocal” has splintered since the Paris Accord a decade ago.
Speaking at the international climate conference in Belem, Brazil’s city gateway to the Amazon, Sir Keir sought to make the economic case for net zero by arguing the green transition would create jobs and lower household bills.
He said: “Ten years ago, the world came together in Paris … united in our determination to tackle the climate crisis.
“A consensus based on science that is unequivocal and this unity was not just international – it was there within most of our countries too.
“There was cross-party consensus in the UK. The only question was how fast we could go. Today, however, sadly that consensus is gone.”
He described green policies as a “win-win” despite pressure from US President Donald Trump, who has repeatedly criticised Britain’s net zero agenda and who, along with leaders from China and India, snubbed the summit.
In an appeal for unity, the Prime Minister said: “The greater our collective ambition, the more progress we make in tackling the climate crisis, and the greater the opportunities we create.
“Just for UK businesses … providing goods and services for the global net zero transition could be worth £1 trillion by 2030.”
He added: “The UK is doubling down on the fight against climate change as an investment in future generations, yes, of course, but also, crucially, as an investment in improving the lives of working people here and now.
“So, look, my message here is that the UK is all in. Because we know you don’t protect jobs and communities by sticking with the status quo, you don’t meet a challenge like climate change by standing still.
“You do it by embracing change, embracing the opportunities, and doing so together.”
Labour came into government pledging to remove almost all fossil fuels from the UK’s electricity supply by 2030 as part of efforts to boost energy security, curb bills, grow investment and tackle climate change.
But the agenda has faced significant pushback from the Conservatives and Reform UK, who have pledged to ditch what they say are “expensive” net zero policies and repeal climate legislation.
Meanwhile, the US president has vowed to “unleash” oil and gas drilling as he pulled the world’s second-largest greenhouse gas emitter out of the 2015 UN Paris Agreement to limit global warming.
The Prime Minister travelled to Belem along with Energy Secretary Ed Miliband and the Prince of Wales on Thursday, having attended William’s Earthshot Prize ceremony on Wednesday night.
Following his speech, he met President Luiz Inacio Lula da Silva of Brazil for a bilateral meeting which media were not allowed into.
A Downing Street spokesperson said the pair “spoke about the importance of multilateralism and international collaboration to tackle climate change”, discussed joint efforts on clean energy and agreed on the importance of taking “transition efforts very seriously”.
Sir Keir also met Barbadian prime minister Mia Mottley, telling her the “devastating scenes” following Hurricane Melissa “were an urgent and sobering reminder of why we cannot – and we will not – stand by and wait to tackle climate change”, according to the readout.
During his visit, Sir Keir hailed a series of new investment deals for UK clean power, including a £100 million commitment from Jera Nex bp and En BW to Belfast Harbour to support the delivery of two offshore windfarms, which No 10 estimates will create around 600 jobs altogether.
However, a decision not to invest in a Brazilian-led rainforest fund threatened to overshadow Sir Keir’s efforts to show UK leadership on climate action.
The Government has decided not to commit public money to the Tropical Forest Forever Fund, which Cop30 host nation Brazil wants to launch at the summit, prompting a backlash from environmental campaigners.
The UK played a key role in establishing the scheme, which would offer financial backing to countries for preserving tropical biomes.
But the Treasury reportedly questioned the potential cost as Chancellor Rachel Reeves grapples with balancing the books ahead of the Budget.
Downing Street said on Wednesday the Government would continue to support the initiative and explore ways to “bring the full weight of the UK private finances sector” behind the scheme.
Sir Keir later insisted “there will be financial leadership” when questioned about the UK commitment to green initiative later on Thursday.
“There will be financial leadership, and the turning point, if you like, the theme of Cop and all the discussions is, how do we leverage in private finance,” he said.
“How do you make this an investment-led initiative, so that it’s not just about giving money or donations?”
However, the WWF said failing to invest in the fund “falls short” of Sir Keir’s commitment for the UK to be “all in” on climate action and urged him to reconsider the move.
Greenpeace said the Prime Minister should put “his money where his mouth is” and offer funding to the scheme, while ActionAid called on the UK and other nations to “ramp up their ambition” on the green transition.
Co-executive director Areeba Hamid said: “Keir Starmer boasts a domestic record stronger than most, having promised to end new oil and gas here in the UK – a genuinely world-leading policy.
“But, with a climate denier at the helm of the world’s biggest superpower, it is absolutely vital that the UK takes up the mantle on global climate leadership and puts his money where his mouth is.”
Friends of the Earth welcomed the Prime Minister’s message, but said Britain must go “further and faster” and called on Chancellor Rachel Reeves to “show she’s all in too” by providing more money for energy transition in the Budget.
Questions have been raised over the scope of summit after leaders from three of the world’s major economies – America, China and India – did not attend.
But the Prime Minister insisted the the UK “can make a difference” despite their absence, telling broadcasters: “Yes, we can make a difference, and we must make a difference.
“Climate damage is one of the defining issues of our time, and it’s not going to go away.”
Conservative leader Kemi Badenoch suggested Sir Keir should focus on the UK’s domestic issues over attending Cop.
During a visit to Staffordshire, the opposition leader said: “Keir Starmer has gone to a conference where the four biggest polluters – the US, India, China, Russia – are not there. That means that nothing serious is going to be happening.
“If those four countries aren’t doing anything, Keir Starmer should focus on fixing the domestic problems we have in our country first.”
Mrs Badenoch also suggested Sir Keir was the “only person” from a “serious country at that conference”, where other European leaders including France’s Emmanuel Macron are also expected to attend.
The Prime Minister later took a veiled swipe at the Tory leader, saying “those that say we shouldn’t go after green jobs in the future need to go and talk to those who are doing these jobs and tell them that they don’t really value their jobs.”
“Those that say now is the time to look away… I think are just fundamentally wrong,” he said.
A Labour source said the Tory leader was adopting outdated arguments to appeal to her dwindling number of supporters.
“The Prime Minister has travelled to Cop with the Prince of Wales to show UK leadership on the world stage and delivering jobs and opportunity across Britain,” they said.
“The Leader of the Opposition should look the 400,000 UK workers in clean energy in the eye and tell them she wants to throw it all away.
“And for what? Old, rusty arguments stuck in the past that she’s forced to adopt because her dwindling number of supporters demand it.”
