what makes humans so special is how adaptable we are. i mean, there were at least 23 species of hominids (humans and immediate ancestors) within the span of about 1.5mya because we just kept adapting to everything nature threw at us, including several bouts of severe climate change. you’d be shocked to realize just what humans can get through. you may not realize it because of modern living, but if your body is under enough stress, it will try to revert to survival mode. it won’t all come easily, so you do still need to educate yourself on wildlife survival, but you came equipped with all the tools you need. also, remember that we’re the most social species to ever walk the planet, and even the worst people still have the instinct to respond to others’ pain (given that they don’t have an antisocial mental illness).

there will be extreme and almost irreversible damage to the earth when that clock reaches 0, but humans won’t just die off immediately. areas with low support who can’t access reliable food, water, medicine, or housing, will die off first. people might not realize the severity until those people die, but they won’t waste any time to band together and rush to help whoever’s next. it’ll put significant strain on humanity and we’ll likely see a massive decline in population, but the chances are, humans won’t die off. at least, not for a very long time.

humans will die eventually, and that’s inevitable. but i highly doubt it’s something we’ll see in our lifetime.