My take is it's actually a reactive move to counter his issuing more fracking permits in 2020 than 2019. This is CA, he's vulnerable on climate issues. I do believe he (like most CA residents) are acutely worried about climate change, but I think this particular action is more about optics than change.
Because the state EPA sets the rules and the EPA is an executive branch function. State congress can overrule it by passing a law, but policy of an executive branch of government can be decided at whim by the governor.
