The need to stabilize the greenhouse gas concentrations of the atmosphere is the great environmental challenge of this century. To control these concentrations, humanity can reduce fossil fuel emissions and/or identify mechanisms to remove greenhouse gases once they have been emitted.

The scope of the problem is challenging because of the size of the fluxes involved. Presently, industry, transportation, and domestic use emits nearly 10 Gt CO2 to the atmosphere annually, and there is no immediate hope for a drastic reversal of these rates of emission. Thus, sequestration of atmospheric carbon dioxide as organic carbon in the biosphere attracts attention as an alternate way to help stem the rate of greenhouse gas growth and associated changes in our climate.

For nearly 2 decades, researchers in the soil science community have studied and estimated the potential of sequestering carbon in soil organic matter. The premise is inherently rational: nearly 10,000 years of cultivated agriculture has reduced global soil carbon by 116 Gt (4), an amount equivalent to more than a decade of the present rates of industrial emissions. Through changed agricultural techniques, it is proposed, much of this carbon can be restored to domesticated soils and thus serve as a significant tool to mitigate climate change, providing a wider timeframe for society to decarbonize.

Unfortunately, both cultural and scientific challenges suggest that this proposal is overly optimistic and inherently flawed.