Wildfires happen because hundreds of millions of years ago, photosynthesis developed and created an atmosphere with roughly 20% oxygen. When plants dry out as they have done for thousands of years in California, they burn and when one burns, that often sets the neighbors on fire and before you know it, you have a "wildfire". Humans got involved and started messing with the natural fire cycle. Fires used to come through every decade or so and clear out the brush and small trees. Now we have a build up of brush and too many too densely populated trees that get diseased which exacerbate the fire problem even more. Then fires move through, they burn so intensely that they tend to burn the big trees as well. People have moved into vulnerable areas and we end up with a dangerous situation. Alarmists like to blame our CO2 because that is what they do, regardless of science or common sense. We need to manage our forests better. It might help if we stop having Washington DC managing so much of our forests from thousands of miles away.
The reason it is happening today is because it is very windy today, at least in southern California. That enables the O2 mentioned above to spread to those dry plants also mentioned.
Since I live in California, I know it is a bureaucratic microcosm of DC. It has regulations and rules and often those regulations are harmful to the environment. I grew up in the Black Hills of South Dakota and I learned what a healthy forest is. In South Dakota, in some areas, they had forest service workers mark trees that could be felled for firewood or other purposes but they ensured that the strongest healthiest trees were usually left alone. Those areas tended to be good healthy forests with lots of wildlife and food. Forests that were poorly maintained were often lodgepole pine so thick you could harldly walk through and they were diseased, and not much lived there. I don't know if something like that would work here in So Cal. Up in northern California, it seems they clear cut everything and then regrow and I'm not a fan of that type of management.