One of my "favorites" is the "world without clouds" scenario, which for the record, I consider unlikely, but is horrifying to imagine: https://www.quantamagazine.org/cloud-loss-could-add-8-degree...
What we're dealing with are "unknown unknowns": what tipping points might exist that we don't know about, that might result in more warming faster than expected based on today's science? We shouldn't take those kind of existential risks.
We aren't struggling at all, though. We just eased off the accelerator a little. (Assuming that our accounting is correct, and that methane leakage isn't worse than we think. [1])
[1] It's worse than we think.
I need to retain some optimism, or I get too depressed to keep on. In this case, my optimism is that solar/wind and batteries will drop enough in price that fossil fuels become economically unfeasible.
It seems possible! I just hope it isn't too little, too late.
("Without"? Well, nobody today knows how to build a cast-iron plough.)
I don't believe this scenario is likely. For one thing we're not headed for 8C of heating; for another, technological change seems to be coming just in time to head off the very worst outcomes, assuming we struggle hard enough.