A time traveler’s survival guide. The vertical green bars are the only times in Earth’s history with enough oxygen to breathe (hypoxia) and low enough to avoid oxygen toxicity (hyperoxia):
That blue bar is extremely pessimistic. Humans can survive pretty well with 15% oxygen, and do so in several places in the Andes mountains, China and India. I wouldn’t recommend doing it without lengthy acclimatizing, especially not considering my last paragraph, but it’s completely survivable by itself.
Humans also don’t really have a problem with 25% oxygen, although that will definitely bring down the life expectancy.
On the other hand, note how those pointers talk about giant insects, megafauna and other scary things. Those are a much bigger problem than the air you’re breathing.
A time traveler’s survival guide. The vertical green bars are the only times in Earth’s history with enough oxygen to breathe (hypoxia) and low enough to avoid oxygen toxicity (hyperoxia):
https://fedia.io/media/cache/resolve/entry_thumb/fa/a9/faa97017c09ebf7d9543fece447951844e5cfbdaa9f491c95763102e987ffc59.jpg
That blue bar is extremely pessimistic. Humans can survive pretty well with 15% oxygen, and do so in several places in the Andes mountains, China and India. I wouldn’t recommend doing it without lengthy acclimatizing, especially not considering my last paragraph, but it’s completely survivable by itself.
Humans also don’t really have a problem with 25% oxygen, although that will definitely bring down the life expectancy.
On the other hand, note how those pointers talk about giant insects, megafauna and other scary things. Those are a much bigger problem than the air you’re breathing.