Soft apocalypse is the concept of society collapsing slowly and without a catastrophe. Usually characterized by the decline of technology, abandoned cities full of wildlife. The surviving humans would be focused on food, shelter, working together as a community rather than fighting or having to deal with whatever world ending event that may be occurring. Any technology they have might be solar, wind, or any other renewable energy source rather than a fossil fuel.
'soft apocalypse' by Will McIntosh
Yokohama Kaidashi Kikō by Hitoshi Ashinano