Those statements are so vague in measurement as to mean nothing.
I've read the IPCC report and the relevant section says nothing of generalized society ending collapses as people would seem to want you to believe.
There's a few that you can read about:
1. A collapse in permafrost may occur (low confidence); 2. collapse of Maize in some regions, may exist under 3°C or more of global warming (low confidence)
etc...
Ok, those aren't great or desired things, and we need to mitigate that, but the world isn't ending. This isn't even close to a world war, a nuclear bomb going off, a massive solar event that takes out the grid etc...
I'd love to see way less apocalyptic language used and more talk about tradeoffs and realistic possible future costs of how we produce and consume vs finding sustainable growth.
As far as food shortages, that just requires a significant reduction in arable land. The US will probably be fine, but countries which rely on farming/production near the coasts will suffer.