As we become more aware of the potential causes and consequences of climate change we are left wondering: who is responsible? Climate change has the potential to harm large portions of the global population and, arguably, is already doing so. Further, climate change is argued to be human-caused. If this is true, then it seems to be the case that we can analyze climate change in terms of responsibility. I argue that we can approach environmental harms, such as climate change, through a theory of collective responsibility. I propose an account of reductive collective responsibility that can apply to the unstructured collective causing climate change and determine what we are each individually morally responsible for. To avoid the critiques of reductive collective responsibility for large unstructured harms, I propose we separate the determination of membership and eligibility for responsibility from the attribution of responsibility. Through this method, I can speak to the individual responsibility of each member who contributes to climate change without holding them responsible for that which is outside their control.