"If we made a huge jump in climate action (whatever that means..what does it mean?), what is the worst that can happen? "
Well.. The obvious one is that we might spend hundreds of billions of taxpayer money investing in stuff that has no return. That may give us an unworkable electricity grid with power so variable we have daily blackouts for a few hours here and there, like most of Africa. Of course the taxpayers don't have hundreds of billions, so the Govt will borrow it & expect the next generation to pay it back, which means the next block of Govts will just inflate the shit out of money until the debt is worthless.
Its really about heading down a dead-end road. Comparable to spending Australia's energy budget just mining Bitcoin, then having everyone rush off and use something else. There is a lot of ways to throw money away, and Govts know them all. Of course we may still be whining about global warming and pouring money in when the next ice-age hits and you'll never find a politician or "influencer" who would own up to their stupidity!
I'd be quite happy is there were no regulations forcing people to use renewables, and no subsidies. That way we will get new ideas that are actually economic. But instead some brainless shit on Council in Orange calling for Council to "create a market for recycling"!! That's is the epitome of throwing ratepayer's money away! We should have all that stuff running on private investment, so when enough people believe in it they will adopt it.
Maybe we should be adopting one of the many newer forms of nuclear energy. Maybe we should just burn coal or gas and grab the particulates & sulphur from the exhaust, but while its politics and not economics, we can't discover the real price of energy. As for the IPCC, NONE of their predictions in the last 20 years has come true, so they just don't count!