We need more science, but what we especially need is science fiction.

The problem is that for almost any feature of humanity that you can name, whether it's the ability to suffer, whether it's the capacity to reason, whether it's having lives that can go better or worse, there are at least some other non-human animals that have all of these features as well. So to exclude non-human animals from the range of moral concern but to include all humans, just seems morally arbitrary.

Climate change is not going to be prevented. It's not even going to be mitigated to the degree a rational person would want. As a result we're going to have to live with climate change and try to reduce the extent and rate of change as much as possible. This is not an inspiring or sexy project.

The density of human population combined with the development of powerful and largely unconstrained technology has given us the problems of the anthropocene and the serious possibility of self-caused extinction.

The idea that Bentham and Mill were maximizers is the greatest stretch of all. They were progressivists, committed to improving the societies in which they lived, not utopian maximizers.

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.

When it comes to climate change it's all the usual barriers: greed, mendacity, ignorance, short-sightedness and so on, manifest in the extreme power of corporations, the weakness of government, and the indifference of citizens.