Gov. Jerry Brown and Canadian leaders announced on Wednesday that Quebec would join a growing pact to reduce greenhouse gas emissions and called for local governments to "light a fire" under national politicians.
"Climate change doesn't wait for anybody," Brown said. "We're not doing enough. We're taking baby steps."
Asked whether he had a message for politicians who don't think climate change is a problem, the governor said, "Get with it."
Brown is also working to expand California's cap-and-trade program, which puts a financial cost on carbon emissions in order to reduce pollution. Quebec has already joined, and another Canadian province, Ontario, is taking steps to become involved.
The governor is scheduled to deliver a speech at the Climate Summit of the Americas at 1 p.m. Eastern time.
The pact that Quebec is joining was announced earlier this year in Sacramento with political leaders from Europe, Latin America and the United States. Although it's not legally binding, signatories have pledged to cut emissions to at least 80% below 1990 levels, or less than 2 metric tons per capita, by 2050.
"It is impossible for any one jurisdiction to do this alone," said Ontario Premier Kathleen Wynne. "We're here to build momentum."
In an interview earlier in the week, Brown said it was important to tackle the issue "from the bottom up and break the ice and get things moving."
States and provinces aren't likely to have an official voice later this year during negotiations in Paris intended to forge a global environmental accord. But Mark Kenber, chief executive of the Climate Group in London, hopes smaller governments can demonstrate that larger progress is possible.
"They say states are the laboratories of democracy in the U.S.," he said. "Globally, that's certainly the case."
Besides, Kenber said, "anyone who has followed the international climate process knows it's not exactly smooth running."