In 2016, California took the lead among U.S. states in addressing climate change by extending legislation to curb greenhouse gas emissions. Targeting both power plants and vehicles, the state committed to the goal of curbing carbon emissions to 40% below 1990 levels by 2030. Laws passed in 2006 had already set targets to reduce emissions to 1990 levels by 2020.

Together, two American politicians, Democratic California Governor Jerry Brown, and Republican former Governor Arnold Schwarzenegger, took a message about fighting climate change to the United Nations’ Climate Change Conference in Paris, France, in 2015. Brown also helped design an effort urging leaders of states, cities, and provinces around the world to commit to standards beyond what national leaders would adopt.

California, and most western U.S. states, rely heavily on snowpack each winter to resupply surface water streams and lakes. Lack of winter storms and warmer temperatures results in low snowmelt levels and depleted water supplies.