High CO2 boosts plant respiration, potentially affecting climate and crops Peer-Reviewed Publication. University of Illinois at Urbana-Champaign, News Bureau ...

This kind of respiration is a reversal of the photosynthesis reaction: glucose and oxygen combine to release energy, with water and carbon dioxide as waste products, instead of the other way around.

In a process known as cellular respiration, organisms use oxygen to oxidize substrates (for example sugars and fats) and generate energy. The Earth formed approximately 4.6 billion years ago.