Just compare IPCC FAR (1990) with IPCC AR6 (2021). We have seen 3 C warming by the end of the this century go from being among the most optimistic "reasonable" estimates to something closer to the central expectation. What was once the most optimistic expectation is now the central expectation.

Yes but mostly because we had the worst case incorrectly calculated, not from meaningful action. And uncertainties leave broad confidence intervals which very well will surprise to the upside

When I first proposed a zero emission target at a Congressional briefing, in 2005 the audience laughed thinking it was ridiculous. Now it is national policy for most countries in the world. (kudos to Elizabeth Kolbert) www.newyorker.com/magazine/200...

Exactly. I've taught greenhouse gas emission reduction for 25 years. Technological progress has consistently exceeded expectations. (Policy consistently disappoints.)

No prediction beyond 2050 has any real plausibility given how radically human behaviour will be forced to change by 2040