We have an atmosphere that is roughly 21% oxygen. The rest of it is largely nitrogen. There's just enough carbon dioxide (CO2) to drive photosynthesis. That has been, throughout the history of our species, pretty stable. Until recently.
Sylvia EarleThe Arctic is an ocean. The southern pole is a continent surrounded by ocean. The North Pole is an ocean, or northern waters. It's an ocean surrounded by land, basically.
Sylvia Earle