These transformations drastically alter the cycle of carbon accumulation and distribution on the land surface. The amount of human induced CO 2 appears to exceed the amount accumulating in the atmosphere and oceans. Accumulating evidence points toward this carbon being absorbed in the temperate latitudes of North America, Europe, and Asia. The Global CO 2 Budget can be defined as the balance of CO 2 transfers to and from the atmosphere. The transfers shown here represent the CO 2 budget after removing the large natural transfers which are thought to have been nearly in balance before human influence.
Units are in metric tonnes of carbon per year.
Budget figures shown here are for the 1980's. Carbon cycle interactions can be extremely complex. For example, agricultural practices increase erosion, which tends to decrease the fertility and carbon content of soil, the largest carbon reservoir on the land surface. Some of the carbon depleted by erosion from upland soils is transported downslope and buried at the base of hillslopes, on floodplains and in reservoirs. Once buried, most of this carbon is no longer available for exchange with the atmosphere.