"Direct satellite measurements of carbon dioxide will have as dramatic an impact as the Hubble Space Telescope within the Earth science field," said Philippe Ciais of the Laboratory for Climate Sciences and the Environment (LSCE) in Gif-sur-Yvette, France.
"It should give us a completely new picture of something more or less completely unknown, showing us the carbon flux across tropical areas such as South America and Africa, where we basically have no data available right now."
The total number of carbon atoms on Earth is fixed – they are exchanged between the ocean, atmosphere, land and biosphere, through a set of processes known as the carbon cycle.
The fact that human activities are pumping extra carbon dioxide into the atmosphere, by burning carbon that has been locked up in the Earth, is well known – the overall concentration of this leading greenhouse gas has increased by a third since the Industrial Revolution.
However, only around half of the extra carbon dioxide human activity sends into the atmosphere stays there, unidentified 'sinks' on the land or ocean surface absorb the rest. The rate of climate change would be much greater without this absorption, but as long as its distribution, strength and variability remains uncertain, the continuation of this effect cannot be taken for granted. In future, global warming may shut it off, or even throw it into reverse.
http://www.sciencedaily.com/print.php?url=/releases/2005/06/050612111201.htm