> So we are no longer worried about catastrophic or runaway climate change based on these revisions?
Don't listen to mc32, they're intentionally confusing the issue. This is the paper they're presumably referencing from last month[1].
The IPCC reports are based on a number of carbon emissions scenarios based on how the world acts: how do countries coordinate, what are the mixes of new electricity generation that come online, how are old fossil fuel plants shut down, what cars are sold, etc. In their reports they simulate multiple scenarios to show what could happen depending on the choices made, since you can't really simulate policy decisions (like presidents paying companies billions to shut down wind projects), wars (ahem), and economic changes.
There were five main scenarios in the IPCC sixth report, from very low to very high GHG emissions.
What was "walked back" is not about climate simulation or feedback loops, but they've retired the very high emissions scenario they developed in the mid 2010s of a world that went all in on heavy economic growth all powered by fossil fuels and little effort toward electrification or decarbonization.
Basically based on renewable energy prices in the years since, electrification, etc, it's just not plausible that the world will grow in that way, so it's no longer worth trying to do simulations based on it.
Note that this was literally called the "very high emissions scenario" in the report, and that's there's still a "high" emissions scenario that will be included in the seventh IPCC report as an upper bound of plausible emissions. A couple of economic models already estimated that we'll likely emit less carbon than the new upper bound high emissions scenario, the same as it was for the very high scenario in the sixth report. Like then, though, it's still worth simulating because it is at least still plausible, and you never know how things will develop sociopolitically (this paper proposes six scenarios from very low to high and a new "high to low" scenario, see section 2.3) .
[1] https://gmd.copernicus.org/articles/19/2627/2026/
