You are right, but "human civilization will be extinct" is an awkward phrase.

Human extinction via climate change is off the table.

The end of human civilization? Depends on what one means by it. If it means we'll go back to being hunter gatherers it's ridiculous. Some civilizational wide regression is not impossible, but even the direst IUPAC scenario projects only a one digit drop in global GDP (of course, that's the average, it will be much worse in some regions).

Sorry, I meant IPCC (International Panel on Climate Change).

I don't think IUPAC (International Union of Pure and Applied Chemistry) has come out with views on impact of global warming :)

They can’t be doing any worse than APS

Right, the collapse of our current civilization is inevitable. That doesn't mean it won't be succeeded by more advanced ones in the future

Once it collapses, it won't rise again to even an industrial level civilization. Iron ore, copper, coal are no longer easy-accessible. Can't have a new industrial age without those.

> If it means we'll go back to being hunter gatherers it's ridiculous.

Indeed, but even going back to the 19th century would have dire consequences, given our current global dependence on the industrial fixing of nitrogen.

If civilization were to collapse (and I don't think it will, other than from a near-extinction event), I doubt it would be like going back to any earlier time.

Oh, for sure. I am just saying it's not an extinction risk, not that it is not a huge and pressing problem.

I would still bet against going back to 19th century. Worst case scenario for me is hundreds of millions dying and a big regression in global standards of living, but keeping our level of civilization. Which is horrible, it would be the worst thing that ever happened.