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.
Oxygen is really rough on the DNA due to making the cells “rust” which hampers cell division and/or increases risks of mutations or cancers
So those memes that were “warning” that oxygen was dangerous because it created rust in metal rods is actually true ??
Dumb question, but in a very oxygen rich environment, can you just breathe through a paper bag or something? Mostly just breathe your own exhaled CO2 with a bit of O2 leaking in?
Mosquitos are kind of modern, being only 45 million years old, way after the megafauna bugs died.
but think 40cm long, meter wide “dragonflies”, half-meter long “scorpions”, 60cm “spiders” with knifelike front legs and 250cm long millipedes (technically not an insect, but eh)
But if you’re looking for giant mosquitoes, you’re in luck: the very much not-extinct elephant mosquito can grow over 1.5cm long.