 Although much of the literature has focused on who should pay, there is another set of questions concerning responsibilities. To approach it, it is useful to distinguish between first-order and second-order responsibilities, where a first-order responsibility in this context is a responsibility either (a) to mitigate climate change or facilitate adaptation or (b) to bear the costs of mitigation or adaptation or both. A second-order responsibility, in this context, is a responsibility to take action that ensures that others comply with their first-order (climate) responsibilities. (The distinction between first- and second-order responsibilities is made by Onora O’Neill [2005: 428 &amp; 433–436] and is applied to the case of climate change by Caney [2014a: 134–147].) Second-order responsibilities are responsibilities to change the social, economic and political environment so that agents comply with their first-order responsibilities. They can include, for example, disincentivising carbon-intensive options (through, say, carbon taxes or quotas or mandatory regulations) thereby inducing agents to comply with a first-order responsibility to mitigate. Or they can involve incentivising others to discharge their mitigation responsibilities by, for example, subsidising clean sources of energy or by designing the urban environment so that people are more likely to walk or cycle or use public transport rather than drive.