Conservation Ecology: An Overview of the Implications of Global Change for Natural and Managed Terrestrial Ecosystems: Table 1

TABLE 1. Average annual budget of CO₂ perturbations for 1980-1989 (from Schimel 1995). Fluxes and reservoir changes of carbon are expressed in 10¹² kg/yr (= Gt/yr). Numbers are from IPCC WGI (1995), in addition to estimates for terrestrial sink terms from Schimel.

CO₂ budget	10¹² kg/yr	Error^*
CO₂ sources
Emissions from fossil fuel combustion and cement production	5.5	0.5
Net emissions from changes in tropical land use	1.6	1.0
Total anthropogenic emissions	7.1	1.1

CO₂ sinks
Storage in the atmosphere	3.2	0.2
Oceanic uptake	2.0	0.8
Uptake by Northern Hemisphere forest regrowth	0.5	0.5
CO₂ fertilization	1.0	0.5
N deposition	0.6	0.3
Residual (source)	(0.2)	(2.0)

^*Errors are accumulated by quadrature.