Despite the interest in carbon markets or programs for which agriculture could be rewarded for storing carbon, there are still substantive questions about how such mechanisms could be designed to meet this task and be generally acceptable to the international community. One of the most problematic of these issues is the fact that, unlike reductions in emissions, carbon sinks may only temporarily hold carbon out of the atmosphere. Until policy mechanisms that appropriately incorporate the potentially temporary nature of sinks are developed, it is unlikely that agricultural sequestration will gain widespread acceptance. In this paper, the authors introduce and discuss three such mechanisms.