In terms of popular mass movements, the West has it too good frankly and even if conditions were to deteriorate, I think the West is also too alienated. It's the double whammy of simultaneously being too comfortable and too alienated. The wretched of the Earth are a lot less alienated from one another than pampered Westerners, meaning they are far more likely to pursue collective action when faced with a crisis like climate change. Left to its own devices, Western society would more likely collapse and dissolve into smaller social units (tribes, clans, extended family). Without proper political guidance, socialism with Western characteristics would just look like several large extended families living together in a village or a commune with all the hardship that would entail.

However, the West isn't in an isolated bubble but part of the world. I think any potential revolution in the West will be mostly due to external factors rather than internal factors. The bare minimum precondition is that the US has to balkanize first. So a hypothetical German path towards socialism could be German communists backed by the United States of Africa, the People's Republic of China, the Islamic Republic of Iran, and the Russian Federation versus German fascists backed by the Republic of Texas, the State of Deseret, the 7th French Republic, and Galician ultranationalists. If these German communists were to triumph, then they could get political and technological guidance from other Global South countries. Maybe Iran could provide political guidance on how to turn the alienated German masses into socially responsible cooperative people. Maybe Chinese scientists can provide German scientists with the blueprints on how to build a commercially viable fusion plant after German fascists blew up every single nuclear fission plant.