what happens when oxygen runs out???????????????

Question: what happens when oxygen runs out???????????????
- Keywords:
  chemistry,
  element,
  future,
  oxygen
Asked by annabell to Josh on 17 Jun 2013.
- Josh Makepeace answered on 17 Jun 2013:
  
  Hi annabell, thanks for the question.
  
  Thankfully, there’s not much chance of the oxygen on earth running out. All the plants that inhabit our world produce oxygen for us to breathe. When we breathe in oxygen, we combine it with the sugars that we eat to release energy. That makes carbon dioxide, which we breathe out. Plants then take in the carbon dioxide, and with a bit of water and sunlight, they make more sugars and release oxygen! It’s a great cycle, and it means that the oxygen we need to survive is constantly put back into the air.
  
  I suppose if all the plants disappeared we could run out of oxygen before too long, then it’d be good night for all of us!

Question: what happens when oxygen runs out???????????????