What can ecological science tell us about opportunities for carbon sequestration on arid rangelands in the United States?

► Many proposed carbon policies are inconsistent with the ecology of arid rangelands. ► On arid sites non-equilibrium dynamics mean high uncertainty. ► Flux to and from soils and plants is low and variable spatially and temporally. ► Management cannot consistently or predictably sequester additional carbon. ► Conserving rangelands and soil stocks is a more realistic carbon sequestration approach.