56
Sources of California greenhouse gas emissions
(slrpnk.net)
From this report
I'll note that California is a bit unusual, having imposed energy efficiency standards on buildings decades ago (much of the US didn't) and having actively taken steps to substitute solar, wind, and storage for fossil-fuel based electric generation
California really needs to get its car dependency in check. There are small movements in this direction in recent years but we’re decades behind many European countries at this point. Unlike other emissions categories where we’re close to the best performers among large economies.
California at least has a law in place, which makes fossil fuel cars sales illegal. That does not solve car dependency, but at least it massivly helps with the oil problem. California HSR is also going to help a lot.