How well can carbon sequestration be measured?
Several methods can be used to measure the carbon and—more importantly for the atmosphere—the changes in carbon in above-ground and below-ground biomass, soils, and wood products. Statistical sampling, computer modeling and remote sensing can be used to estimate carbon sequestration and emission sources at the global, national and local scales. Current forest carbon estimates are generally more accurate and easier to generate than soil estimates. Estimating changes in soil carbon over time is generally more challenging due to the high degree of variability of soil organic matter—even within small geographic scales like a corn field—and because changes in soil carbon may be small compared to the total amount of soil carbon. More information on these carbon accounting methodologies can be found in the Land-Use Change and Forestry chapter of the Inventory of U.S. Greenhouse Gas Emissions and Sinks, and in the IPCC (2000) Special Report on Land Use, Land-Use Change, and Forestry section on
