On Wednesday, President Trump is expected to roll back Obama-era standards, jeopardizing a decades-old exemption that lets California make its own clean air rules.
Californians want the state to lead the world in fighting climate change, according to a new poll -- and many are ready to tackle the problem on the road, at the ballot box, and even with their pocketbooks.
Automakers backed Obama-era rules on car emissions and gas mileage, then asked President Trump to change them. Now the companies fear a long Washington-California court fight.
Reaching Gov. Jerry Brown's goal of a carbon-neutral California would require massive expenditures on the electrical grid and for zero-emission vehicles.