If you have a flat, fixed view of state interest then it is difficult to understand why some states adopt aggressive climate change policies, even when that risks economically disadvantaging them, and other states do not even when it would be in their economic interests to do so.

Aristotle thought that humans are rational animals and Hobbes thought that we act on the basis of rational self-interest. If only! It's not that we never do these things, it's that they are hardly constituative of who and what we are.

Is it in the interests of Britain to leave or remain in the EU? As we saw in the referendum, there are different Britains and they see their interests in different ways. For a lot of everyday blokes the EU affected their sense of identity in ways they disliked, and they were right in thinking that the EU didn't return much to them by way of economic benefits.

If you look globally you see a patchwork of jurisdictions (nations, states, provinces, cities) that have taken aggressive action on climate change, and a patchwork of jurisdictions that have not. These various policies reflect the politics of each jurisdiction and the values of its citizens.

We can use economic instruments to help realize our goals but economics does not tell us what our goals should be.

Critics of Consequentialism have often assumed that hedonism (or preference-satisfaction) must be the theory of the good, that the deontic principle must be maximizing, and that the principle should be applied to individual acts. Indeed, this version is often called "classical utilitarianism" and attributed to Bentham and sometimes even to Mill. Rather than a "classical" view it is a recent construction foisted on to the tradition.

Climate change involves fundamental choices about how we want to live and what kind of world we want.