California Gov. Jerry Brown, left, walks to sign a climate bill and is followed by former Gov. Arnold Schwarzenegger, right, on Treasure Island, Tuesday, July 25, 2017, in San Francisco. Gov. Jerry Brown signed legislation Tuesday keeping alive California's signature initiative to fight global warming, which puts a cap and a price on climate-changing emissions. The Democratic governor was joined by his celebrity predecessor, Arnold Schwarzenegger, who signed the 2006 bill that led to the creation of the nation's only cap and trade system to reduce greenhouse gases in all industries. (AP Photo/Eric Risberg)