This paper argues that watershed management and sustainable land and water management are key development areas which present a multiple win potential synergy between food security, climate adaptation and climate mitigation. The paper analyses the current context in which carbon sequestration could be both a proper agri-environmental indicator to assess different strategies of sustainable development in watershed approach and a mean to access carbon funding. Project examples (from Cuba, Uganda, Madagascar and Brazil) are provided to show how far carbon sequestration is linked to watershed management and sustainability. It drives to the question “how to facilitate the use of carbon sequestration project estimates to mobilize funds and build carbon-funded Payment of Environmental Services (PES)?” This paper targets the national agriculture sector, forestry and food security policy makers, institution-based, agency and donor decision-makers.