In Balance, with a Little Help from the Plants

What happens to the carbon dioxide emitted during burning of fossil fuels? It is well known that three reservoirs--the atmosphere, the oceans, and the terrestrial biosphere--constantly exchange large amounts of carbon. In his Perspective, Tans discusses recent findings that support the idea of a biosphere nearly balanced with respect to carbon. The new work highlights the role of terrestrial plants in the global carbon cycle and is expected to result in narrowing uncertainties about the net carbon uptake by oceans.