It is possible to remove carbon from the atmosphere and sequester it in forests and forest products, even though the trend to date has been the reverse. Management practices that could reduce or reverse the current emissions of carbon from land include (1) a halt to deforestation, (2) an expansion in the area of forests, (3) an increase in the stocks of carbon in existing forests, (4) more efficient harvest and greater use of wood in long-lasting products, and (5) the substitution of wood fuels for fossil fuels (see Table 1 at bottom of page). It is important to recognize, however, that the rate of global warming needs management as well. Unless the warming is gradual enough to avoid widespread mortality of forests, the additional releases of carbon caused by the warming itself, through increased respiration, decay, and fires, may cancel the intended effects of forest management Regions in Africa with a potential to sequester carbon are shown in Fig. 1.

		Figure 1

The estimates are based on a comparison of today's ecosystems (determined from satellite) with the ecosystems thought to have existed prior to human existence. Human influences have generally reduced the area and stature of forests, and Figure 1 shows where human modifications are thought to have been light, medium, and heavy. These areas represent the regions with the greatest potential to re-accumulate carbon through such practices as allowing natural forest growth, planting forests, or establishing agroforestry, the practice of combining trees with agriculture. The accumulation of carbon in forests can only continue while the forests are growing, however. Fully grown forests neither accumulate nor release carbon. Thus the strategy with the greatest potential for keeping carbon out of the atmosphere indefinitely is to replace fossil fuels with wood-derived fuels that are sustainably produced.

	Table 1. Annual emissions (+) and accumulations (-) of carbon (PgC yr-1) resulting from land-use change during the 1980s and estimated accumulations possible in the future under different management strategies. The last column offers estimates of the total amount of carbon (Pg) that might be withheld or withdrawn from the atmosphere by improved forms of management or as a result of environmental changes.

	1. These values are negative because stopping deforestation would have the effect of keeping this much carbon on land. Conversion of the world's forests to agricultural lands is estimated to release 400 to 500 PgC to the atmosphere from oxidation of plant material and soil carbon. 2. The accumulation of carbon in mid-latitude forests according to forest inventories is assumed here to have been caused by processes outside of human control, but they may have resulted from better management. 3. Emissions of carbon from wood-derived fuels add little net carbon to the atmosphere because they are approximately balanced by the accumulation of carbon in regrowing wood. Emissions from fossil fuels, in contrast, are not balanced by production of new fuel, so the substitution of wood for fossil fuel reduces emissions overall.
	(Return to Top of "Using Forests to Sequester Carbon")
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