A possible Democratic contender for the White House says he's at the COP summit with an "open hand not a closed fist" - as he vowed not to let China dominate the green space.
California Governor Gavin Newsom has for months been teasing a bid for the next presidential election in 2028.
Sky News asked him at COP30 in Brazil if he was using it to drum up support for his campaign.
"I'm here in the absence of leadership from Donald Trump, who's abdicated responsibility on a critical issue," he said.
The Republican president has ignored the meeting of tens of thousands of people in Belem, leaving the stage wide open for Democrats to swoop in and lob criticism from afar.
Mr Newsom is a longstanding political foe of US President Donald Trump - they trade insults like "Gavin Newscum" and "The Nodfather".
He added the switch to green energy is about "more than electric power".
"It's about economic power," Mr Newsom said, "and I'm not going to cede America's economic leadership to China."
When he took office this year, Donald Trump cancelled clean energy projects and subsidies.
Meanwhile, China is making eight in ten of the world's solar panels and five in ten electric vehicles - while also producing more coal than any other country.
The US president is fighting back for the domestic oil and gas industry by trying to sell more of it abroad.
But in doing so he has given China more room to dominate green markets, Democrats say.
The US and China have been locked in tariff threats and trade wars this year.
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'Open hand, not a closed fist'
Mr Newsom said at another event at COP30 today California was going to "lean in" and "compete in this space".
"But we can't do that without all of you… So we're here with an open hand, not a closed fist."
Democrats have been pounding the hot and humid hallways in Amazonian Belem to tout California's "climate leadership".
The state doesn't have any formal say in these inter-governmental negotiations. But as the fourth-largest economy in the world, it does wield influence in energy markets.
California gets two thirds of its electricity from renewables, but also still imports 300,000 barrels of oil a year, the second-biggest provider of which is the country hosting the climate summit, Brazil.
Republican states were also faster to roll out renewable power than Democrats. Sky News put that to California senator Josh Becker yesterday, also here on a PR exercise for the state.
Mr Becker said the fact that Republican Texas had rolled out more solar and wind than California was "a good thing that shows that it's economically competitive".
"It's actually cheaper. That's really why they did it," he said. "Not necessarily because of climate action. And that's good news. So we're all for that."
(c) Sky News 2025: California governor Gavin Newsom accuses Donald Trump of 'abdicating responsibil
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