ABSTRACT
The 20th anniversary issue of Global Environmental Change provides an important opportunity to address the core questions involved in addressing “global environmental” problems-especially those related to climate change. Climate change is a global collective-action problem since all of us face the likelihood of extremely adverse outcomes that could be reduced if many participants take expensive actions. Conventional collective-action theory predicts that these problems will not be solved unless an external authority determines appropriate actions to be taken, monitors behavior, and imposes sanctions. Debating about global efforts to solve climate-change problems, however, has yet not led to an effective global treaty. Fortunately, many activities can be undertaken by multiple units at diverse scales that cumulatively make a difference. I argue that instead of focusing only on global efforts (which are indeed a necessary part of the long-term solution), it is better to encourage polycentric efforts to reduce the risks associated with the emission of greenhouse gases. Polycentric approaches facilitate achieving benefits at multiple scales as well as experimentation and learning from experience with diverse policies.
