Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.
As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades:
How much each change to the atmosphere has warmed the world:
Recommended actions to cut greenhouse gas emissions in the near future:
Anti-science, inactivism, and unsupported conspiracy theories are not ok here.
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 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.