Does the IPCC report anywhere claim that climate change is an existential threat? What does a "code red" actually entail for the next century? Where in the climate science does it actually say that large ares of Earth will become functionally uninhabitable and the biosphere will collapse? Outside of hothouse Earth scenarios, which are deemed unlikely at this point within the 2.5-3.7 degrees warming scenarios, I'm not aware of any such doomsday predictions by the actual mainstream climate science.
IPCC AR6 (2022)'s summary for policymakers [1] makes such a claim.
Here is the last paragraph:
"The cumulative scientific evidence is unequivocal: Climate change is a threat to human well-being
and planetary health. Any further delay in concerted anticipatory global action on adaptation and mitigation
will miss a brief and rapidly closing window of opportunity to secure a liveable and sustainable future for all. (very high confidence)"
I don't see where in that sentence it says large parts of the planet will become functionally inhabitable or that climate change is an existential threat.
"rapidly closing window of opportunity to secure a liveable and sustainable future for all"
It literally says "livable future." As in, a future that is as livable for humanity in general as the present currently is.
There are numerous scientists that predict sea level rise coupled with lethal wet-bulb temperatures in the tropics will make living around the equator difficult if not impossible. Here is a direct quote if you need it:
"SSP5-8.5 — Imagine a world where humanity doesn’t just do nothing about climate change but continues to make it worse... The net result would be 4.4°C of warming, with a range between 3.3°C and 5.7°C. As if large-scale coastal inundation and extremely destructive weather weren’t enough, parts of the planet would become unlivable during the hottest times of the year."
That's a timeline in which we continue to increase emissions year over year and actively double down on business-as-usual. So far, that has been the case (emissions dipped in 2020 during lockdown, but we are now back to emitting more than ever before).
