The mission of CalEPA is to restore, protect and enhance the environment, to ensure public health, environmental quality and economic vitality.

[7] CalEPA should not be confused with the similarly named federal United States Environmental Protection Agency (EPA).

CalEPA was created by Governor Pete Wilson by Executive Order W-5-91 in 1991, following on a "Big Green" initiative Wilson proposed during the 1990 state gubernatorial elections, promising a cabinet-level agency to oversee state environmental regulations and research.

[8] Following inter-agency reorganizations led by the governor with review by both houses of the California State Legislature, the agency became a cabinet department on July 17, 1991.

[citation needed] In June 2008, CalEPA announced that new global warming performance labels would be placed on all new cars effective on January 1, 2009.