What can the Mars rover tell us about climate change on Earth?

http://m.guardian.co.uk/environment/2012/aug/07/mars-rover-climate-change-earth?cat=environment&type=article
One of the things that Curiosity is going to help us learn much more about is... How does carbon cycle through the system? Where does it go? Where does it end up? Does it ever come back again? Is it ever buried deep enough that it come back again from volcanoes