On the main point. Yes, correlation is easy. Causation? I don't know, because I don't work in climate science. Is obvious correlation sufficient to establish causation in climate science?
Causation between human activity and climate change resulting in that temperature anomaly, is fundamentally hard. Especially in a field like climate science where every model carries a big bundle of assumptions some of which are just educated guesses.
But the models for anthropogenic climate change have been pretty bang on at predicting the temperature anomaly that we're seeing today. That doesn't formally prove causation but it's certainly enough evidence that we need to start acting to mitigate climate change now, there's no more 'complicated analysis' needed. At this point it's a bit like arguing over whether hitting the iceberg is really what's making the titanic sink, while standing on the submerging deck.
OK. I got downvoted on this. What is wrong here?
What you're asking is the equivalent of 'is it now established that the deck of the titanic increasingly submerging underwater is caused by it sinking?'.
Like, are you seriously asking whether scientists have looked into whether high temperatures and low rainfall cause dry forests and whether dry forests burn more easily? Do you really think it is a big unsolved question in science whether hot air dries stuff and whether dry stuff burns more easily than wet stuff, and maybe it's actually dry stuff that makes air hot and the fire causes the things to have been less wet before they burned?
Are you saying without climate change, this Australia wildfire would never have happened?
That's not just possible, it is obviously the case. But that's simply the wrong question.
> Are you saying without climate change, this Australia wildfire would never have happened?
No, I am obviously not saying that, and it is again the wrong question.
The whole error here is thinking that there is one single cause. There isn't. Tons of factors contribute to in the end the fires that we are seeing now. As is unavoidably the case in such situations, you essentially never can directly relate any small aspect of the result to any particular causing factor. But that does not make it wrong to say "X caused Y".
Smoking causes lung cancer. It is nonsensical to reply to that "Is it possible some other health factors, other than smoking, cause lung cancer?" or "Are you saying without smoking, we would not have any lung cancer?" Just because it is hypothetically possible that in some random year all lung cancer cases could have causes other than smoking, which we would never know, does not make it wrong to state that smoking causes lung cancer. We know statistically that smoking causes lung cancer, and we know statistically how many lung cancer cases we can avoid by not smoking. Whether any particular case of lung cancer was caused by smoking is simply completely irrelevant.