Noisome has been in office just ~7 1.2 years. While CA oil production probably has declined some during his term, that percentage decline probably spans decades and some of the percentage decline is from oil production increasing and/or coming online in Texas, the Gulf of Mexico, and Alaska.
Noisome has been moronic, a captive to the Enviros, but not 40% of US production to 2% moronic. Plus or minus Deukmejian and/or Wilson, the "credit" for the decline - to the degree Sacto was a cause - is shared by every CA governor since ~1975. Don't mentally let Moonbeam 1.0 & 2.0, Davis, and Ahnold the RINO off the hook.