The leader of the world’s fourth biggest economy, California governor Gavin Newsom, has explicitly endorsed a global phase out of the fossil fuels that drive climate breakdown.

Newsom told the Guardian that California is “100%” behind the efforts of the so-called Santa Marta coalition, a group of more than 50 countries that includes many of the world’s largest economies, to transition away from oil, gas and coal toward solar, wind, batteries and other non-carbon energy sources.

Speaking at the Cop31 UN climate summit on Thursday, Newsom said: “When you have a product that is obviously superior, which clean energy is for the climate and the economy, why wouldn’t you make that shift as quickly as possible?”

As the head of America’s most populous and economically powerful state, Newsom is the most prominent US politician at Cop31, a process the administration of US president Donald Trump continues to boycott.