Continuing with your alas-all-too-regular diet of not-science here. But there is so little real going on. Anyway, Eli is pushing Machiavelli, and a while ago PK asked “How would Hobbes organize society to avert climate change?”. I had no answer, so I ignored the question, but now return to it.
Hobbes has little to say directly about policy: his focus is on the justification and structure of government. Read Leviathan. He is a great believer in a strong central authority, and the meaningless of contracts made without a power to enforce them. So stuff like Kyoto would be out. Hobbes view is that the primary responsibility of government is Peace; or in other words the security of the population; the sovereign can and should do anything necessary to achieve that (see part II for details). Implicit in this is a long-term view; combining that with prevention of disorder, you could plausibly argue for a Hobbesian sovereign to take preventative action on climate change.
Given that, I can see no reason why said sovereign wouldn’t like a carbon tax. All the usual arguments against it – basically, the PR-campaign junk that its hard to get past the legislature or voters – collapse in the face of strong long-term centralised government. Hobbes is also keen to stress that it is in our reasoning that we agree, and it is thus conducive to peace; whereas in our passions we disagree, and it is therefore conducive to discord. He would not be impressed by the level of debate at many a blog [*]. Hobbes is strongly opposed to corruption, and argues for monarchy against democracy on the grounds that there are fewer people at the top to corrupt (not that they, individually, would be any better). And carbon-trading stuff is full of opportunities for corruption, so I shall claim Hobbes for my side.
As far as I can tell, nothing else but this is required, for an individual country. He can’t help you get an international agreement, though.
I should also add that the Hobbesian sovereign has a duty to “judge what opinions and doctrines are averse, who shall be allowed to speak to multitudes, and who shall examine the doctrines of all books before they are published”. If the said sovereign decided that denialists were deliberately spreading falsehoods conducive to discord, he would make short work of them. [Note to the obtuse: this post attempts to say what Hobbes would say. It does not necessarily reflect my own views.]
[*] “that they that exhort and dehort, where they are required to give counsel, are corrupt counsellors, and as it were bribed by their own interest” (L 25, “Of Counsel”) is a nice quote, found via this.