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The possibility of using improved farming practices to mitigate the increase in atmospheric CO2 through soil carbon sequestration (SCS) reached international consensus during meetings leading to the Intergovernmental Panel on Climage Change (IPCC) First Assessment Report (1990). The rationale for this consensus was that by fostering the adoption of improved farming practices, it would be possible not only to enhance agricultural productivity but also to make soils act as sinks for atmospheric CO2. A significant amount of scientific and practical evidence has accumulated to date in support of this consensus (Kern and Johnson, 1993; Lal et al., 1995a, 1995b, 1998a, 1998b; Paul et al., 1997; Powlson et al., 1996). In chapter 23 of the IPCC Second Assessment Report, Cole et al. (1996) reported estimates of SCS potential that could be achieved during a 50-to 100-year span. Under a program of global adoption, the international team of authors estimated that approximately 40 Pg C could be removed from the atmosphere via SCS at rates of 0.4 to 0.8 Pg C y−1 depending on the length of sequestration considered. This global estimate was made based on the assumption that it was possible to recover about two-thirds of the 55 Pg C historically lost from the soil organic carbon (SOC) pool by implementing land use conversions (e.g., conversion of marginal agricultural land to permanent vegetation) and improved management practices (e.g., no-tillage agriculture).