‘The biggest transformation in a century’: how California remade itself as a clean energy powerhouse

For the first time, clean energy provided 100% of the state’s power almost every day for at least some of the day in 2025. Photograph: David Paul Morris/Bloomberg via Getty Images

As officials from around the world met in Brazil for the Cop30 climate summit last month, the US president was nowhere to be found, nor were any members of his cabinet. Instead, the most prominent American voice in Belém was that of the California governor, Gavin Newsom.

During the five days he spent in Brazil, Newsom described Donald Trump as an “invasive species” and condemned his rollback of policies aimed at reducing emissions and expanding renewable energy. Newsom, long considered a presidential hopeful, argued that, as the US retreated, California would step up in its place as a “stable, reliable” climate leader and partner.