Question

Is oxygen present on the earth sufficient for the growing population or is it an exaustible resource?

Answer 1

Oxygen can be continuously renewed through the process of photosynthesis by plants; however, seeing as trees are being cut in such large quantities, the balance of nature is being disturbed and hence hypothetically if too much plant life is eradicated (destroyed) then oxygen could be exhausted at some point. This is unlikely to happen in the near future however.