Climate change is a global externality that has proven difficult to address through formal institutions alone due to the public good properties of climate change mitigation and the lack of a supranational institution for enforcing global treaties. Given these circumstances, which are arguably the most challenging for international cooperation, commitment problems and free-riding incentives for countries to delay costly mitigation efforts are major obstacles to effective environmental agreements. Starting from this premise, we examine domestic mitigation efforts, with the goal of assessing the extent to which the willingness of individuals to contribute voluntarily to the public good of climate mitigation could be scaled up to the global level. Although individual environmental actions are clearly insufficient for achieving ambitious global mitigation targets, we argue that they are nevertheless initial and essential steps in the right direction. In fact, individual and community efforts may be particularly important if local interventions encourage shifts in norms and behaviors that favor large-scale transformations. With this in mind, we discuss the importance of the visibility of norms and the role of beliefs when such visibility is lacking and their implications for leveraging cooperative behavior to increase climate mitigation efforts locally and globally.