The global food surplus is projected to continue even in the worst case. Energy and raw material production is similarly not a major concern. People continue to live in Dubai which demonstrate how extreme local conditions can get without forcing exodus. Further, few places are expected to get even that bad.

Yes, changes to weather patterns, sea levels, invasive species, even diseases are likely. But, collapse of civilization is only really a risk if WWIII kicks off.

Agriculture can go a long way with animals, wood, and stone. Extracting energy from wind and rivers is easily attainable from that basis. At which point we would have serious energy to work with. Hydro electric dams provide 6.1% of the total U.S. electricity. That is plenty of energy to kick start industrial manufacturing and get to wide spread solar power.

The next civilization may be extracting most of it’s materials from our cities, but that’s an advantage if anything.