The US state, the fifth-largest economy in the world, has committed to producing 100 percent clean electricity by 2045. The law contradicts President Donald Trump's energy policy, aimed at boosting the coal industry.
On Monday, California Governor Jerry Brown signed the ambitious Senate Bill 100, committing his state to phasing out electricity produced by fossil fuels by 2045.
Brown also signed an executive order directing California to achieve "carbon neutrality" by no later than 2045. "Carbon neutrality" refers to taking as much carbon dioxide out of the air as is emitted.
The law and the executive order seek to fill the void left by President Donald Trump's decision to withdraw from the 2015 Paris climate deal and his efforts to boost the country's struggling coal industry.
"This bill and the executive order put California on a path to meet the goals of Paris and beyond," Brown said at a signing ceremony in state capital Sacramento.
"It will not be easy," he said. "It will not be immediate. But it must be done."
'We need to do more'
California — the fifth-largest economy in the world — joins more than a dozen countries and twice as many large cities in making such a pledge as part of global efforts to prevent an irreversible change in Earth's climate.
"California, as a very prosperous economy, is taking aggressive action on climate change," Brown told AFP. "So I hope it gets France and Germany to up their own ambition, because we all have to do more than we are currently doing."
California, home to some of the biggest technology companies, such as Apple and Google, is pushing to rapidly expand the adoption of electric vehicles. The western US state plans to slash greenhouse gas emissions by 40 percent compared to 1990 levels over the next 12 years.
Climate activists celebrated the signing of the bill:
The new bill mandates California utilities to generate 60 percent of the electricity needed from solar, wind and other renewable sources by 2030.
Business groups have expressed concerns about the new legislation, saying it would raise the price of energy.
"If we're going to have these first-in-the-nation laws, we want to see first-in-the-nation benefits," said Rob Lapsley, president of the California Business Roundtable.
ap/jm (AP, AFP)