Anthropogenic climate change threatens humanity as a whole, making its mitigation a matter of pressing concern. Mitigation efforts at the institutional level are necessary to successfully change the course of climate change, but thus far governments and industries have been ineffective at reducing greenhouse gas emissions. A point of philosophical contention is whether individuals have a moral responsibility to reduce their own emissions given the lack of institutional action. I argue that they do by redefining climate change as a collective (...) impact. Individual emitters share collective responsibility for that impact, which translates to an individual duty to reduce their contribution. (shrink)