All new cars and passenger trucks sold in California will be zero-emission vehicles by 2035.
Governor Gavin Newsom issued a mandate for a ban on the sale of new gas-powered vehicles within 15 years.
The new order is forecast to achieve more than a 35% reduction in greenhouse gas emissions and an 80% improvement in nitrogen oxides levels from vehicles in the state.
According to official figures, transportation is responsible for more than half of all of California’s carbon pollution, 80% of smog-forming pollution and 95% of toxic diesel emissions
Mr Newsom said: “For too many decades, we have allowed cars to pollute the air that our children and families breathe. Californians shouldn’t have to worry if our cars are giving our kids asthma.
“Our cars shouldn’t make wildfires worse and create more days filled with smoky air. Cars shouldn’t melt glaciers or raise sea levels threatening our cherished beaches and coastlines.”