As the international climate negotiations seem to be stalling, hope for change is emerging from the grassroots. A mass movement of grassroots community organizations is joining forces to move the process forward and propose alternatives. They left their farms in Indonesia, El Salvador, Senegal, and many other places to go to Copenhagen to participate in the Klimaforum. They went to Copenhagen (and then to Cochabamba, Bolivia) not only to protest the lack of action on the climate negotiations, but also to propose their own version of climate justice. At the center of their proposal is the Food Sovereignty. Agriculture contributes at least 17% to GHG emissions, most of this is from industrial agriculture and a globalized food system. Food sovereignty goes beyond the popular idea of food security; it is the right of people to define their own food and agriculture, and it is a platform for rural revitalization based on equitable distribution of resources (land, water, seeds, etc), and ecologically sustainable practices. In this talk I examine the concept of food sovereignty as a strategy for mitigation and adaptation to climate change and propose that we, as scientists concern with climate justice, should be collaborating with these social movements in identifying and developing food sovereignty strategies that will generate more equity and move the world toward more climatic stability.