Answer:
I would believe the mesosphere would be the most difficult layer to breathe. Troposphere is where we are, ov we can breathe here, stratosphere would be hard to breath in as well
Hello, to answer your question properly the problem that's effecting the population is the decrease in trees. It causes their nests and homes in the trees to be burned and make them have to migrate somewhere else then that area they were living in.
Signed, Virtouso Sarge