Anyway, these are the sorts of questions that people ask. People ask, what is CO
2
? As we remember, CO
2
is used for photosynthesis. Animals undergo respiration and give off CO
2
. I am simplifying this. Plants undergo photosynthesis and take in CO
2
. The more plants we have, the more CO
2
is absorbed. The biggest absorbers of CO
2
are the oceans. They are the biggest sinks that there are for absorbing CO
2