Limiting future atmospheric carbon dioxide

We estimate anthropogenic carbon emissions required to stabilize future amtospheric CO at various levels ranging from 350 ppm to 750 ppm. Over the next three centuries, uptake by the ocean and terrestrial biosphere would permit emissions to be 3 to 6 times greater than the total atmospheric increase, with each of them contributing approximately equal amounts. Owing to the nonlinear dependence of oceanic and terrestrial biospheric uptake on CO concentration, the uptake by these two sinks decreases substantially at higher atmospheric CO levels. All the stabilization scenarios require a substantial future reduction in emissions. -from Authors