This brief examines how California could limit the production of its principal energy production -- oil -- and the resulting implications for global GHG emissions. By many measures, the U.S. State of California has put in place climate policies that stand among the world's most ambitious. But even climate leaders like California will have to go well beyond existing actions to achieve the goals of the Paris Agreement -- namely, keeping warming well below 2 degrees, plus reaching new zero emissions globally by the second half of the century.