California Gov. Jerry Brown started his global climate summit in San Francisco by saying that President Donald Trump will likely be remembered as a liar and fool when it comes to the environment.
The Democratic Brown and former New York City Mayor Michael Bloomberg held a press conference Thursday on the first full day of the summit that is partly a rebuke of the Trump administration.
Trump announced last year that he was withdrawing from the landmark 2015 Paris climate accord.
His administration is also seeking to boost methane emissions and roll back California's strict vehicle emissions standards.
Summit organizers say they are unaware of any U.S. federal officials attending.