[elbasti]

With all due respect, I don't think you understand what the "worst case" scenario looks like for global warming, and how close we are to that scenario. For reference, check out figure 1 in this nature article [1].

That has warming by 2300 as 8C in an "emissions continue current trends" path.

Here's chatgpt giving a picture of what 8C warming looks like. Speculative, hallucinations, caveat emptor, etc...but to give a sense of proportion this, last time the earth was 8C *cooler* than now, ice covered 25% of the planet:

> At +8°C, Earth is fundamentally transformed. Large parts of today’s populated zones—South Asia, the Middle East, Africa, southern Europe, the southern U.S.—are functionally uninhabitable for humans outdoors. Wet-bulb temperatures regularly exceed survivable limits. Agriculture collapses across the subtropics; even mechanized, climate-controlled farming is marginal. Most of the world’s food comes from high-latitude regions: a narrow band across northern Canada, Scandinavia, and Siberia. Sea levels are dozens of meters higher, drowning coastal megacities; Miami, New York, Shanghai, and London are gone. Phoenix is lifeless desert. Seattle is coastal tundra, wetter but still survivable.

> Civilization persists only in fragments. Mass migration and resource wars have rewritten borders. Population is a fraction of 21st-century levels. Global trade, universities, and modern governance are mostly memories. Local, self-sufficient polities dominate. The United States as an institution likely dissolves or transforms beyond recognition—2 out of 10 chance of recognizable survival. Harvard or MIT survive, if at all, as digital archives or autonomous AI-driven knowledge systems—3 out of 10. The world would still have people and culture, but not civilization as we know it.

Edit: I would appreciate knowing why I'm getting downvoted when I added citations for *possible* warming paths (from nature!). Yes, the chatgpt explanation is speculative but I mean, look at the thread we're discussing.

[1]: https://www.nature.com/articles/s41612-020-0121-5

[gmuslera]

Part of the problem of getting +/- 8C of different global temperature is the speed of it. https://xkcd.com/1732/ shows a timeline that goes back to 20000 AC, where global average temperature was like 5ºC less. There has been changes, but also adaptation. Now in less than 200 years we increased 2ºC, and the speed of change has increased, it was around 10 years ago when we reached 1ºC over preindustrial times, and now we are at 1.5ºC.

And without adaptation you get mass extinction. And the human system may be pretty fragile against the disappearance or deep change of key components of the global system.

[antonvs]

I appreciated your comment. I’ll also note that the path to that future will not be fun - you/chatgpt describe a kind of end state 275 years away, but things will evolve to that state over time. I suspect the downvotes may reflect people’s desire not to face the likely reality.