Earlier quoted context omitted.
Why do you think global warming could kill literally every human being? What's the scenario in which that happens?
There's a lot to unpack with this, and I am not an expert, but: crop failure across industrial monocrops leads to food shortages, wild fires destroy significant areas which support pollinator ecologies, fresh water become contaminated by rising sea water and blighted by drought, and perhaps most significantly, as resources become strained, humans become desperate and armed conflict proliferates. This is just top of m…
Bad, sure; I wish they were not present to threaten us, but they are not close to "all".
Humans are extremely resilient omnivores. We are able to eat a huge range of things from algae to zebra, and get food (farmed and hunted) from salt water as well as fresh.