Submitted by abrandis t3_1255xmu in explainlikeimfive
I understand there's a large amount of photosynthesis that creates oxygen especially algae, but humans have produced many machines that use much more than other biological species, shouldn't we be seeing a reduction in the atmosphere?
Way2Foxy t1_je2mbj2 wrote
If we suppose the amount of oxygen "lost" is equal to the CO2 added, which is oversimplified but close enough to get the point across, then the atmosphere has increased by about .02% CO2 over the last few centuries.
The atmosphere is about 21% oxygen, so you can see how that's basically a rounding error with regards to oxygen level.