I’ve said this before – in Carbon Tax Now – but you could be excused for missing it, because that was mostly about carbon taxes, oddly enough. So I’ll be more explicit, here, and argue for solving GHG emissions as a matter of economics, to be handled by taxation, rather than as a matter of morality, to be handled… somehow. Context: Eli wants to handle it as ethics. And a fair amount of the comments on Can global emissions really be reduced? are about this. Disclaimer: I don’t understand economics.
I think this view (the morality view) is shared by, say, Greenpeace, whatever their public pronouncements about costs might be. They think GW is Bad and should be forbidden. Not taxed; not slowed; not ameliorated; not adapted to: forbidden. This is the moral approach: it is a bad thing, so don’t do it.
This is the approach we adopt for, say, murder. Or rape. Or a host of other crimes: they are forbidden. You can’t pay blutgeld as reparations for murder and avoid prosecution: this isn’t ancient Norway, or present-day Saudi Arabia (and let us not complicate the issue by worrying about the rich and lawyers).
But its not the approach we adopt to smoking. Smoking is Bad, but its not forbidden, its heavily taxed. Partly in order to discourage it, and partly as a pure money-raiser, which I admit complicates the analysis. And smoking differs from Murder in that whilst it may be Bad, in that your mummy told you not to do it, it isn’t morally bad1. [Would be nice to throw in another couple of examples here: anyone?]
And emitting GHG’s isn’t morally bad, in itself: only the GW consequences are. But they are “balanced” by “good”s, which are the things we get from burning GHG’s: light, heat, shelter, food, cheap shit from China. I say “balanced” because whilst they are goods and bads, they probably don’t balance. Indeed all economic analyses say that the goods (far) outweigh the bads. Anyway, that is to wander from my point.
Dealing with GHG’s as a matter of ethics throws up the problem that we might well not agree on our ethics. Though dealing with it economically throws up the problem that we don’t agree on the costs, true. Do you think polar bears going extinct is Bad? If so, how Bad? Is it bad enough to rule of GW all by itself (I doubt that would fly) or does it need other buttressing bads (in which case it isn’t absolute). And so on.
Some have raised the “intergenerational moral issue” as though it makes a qualitative difference. I don’t think it does. Indeed I don’t think it even appears in the economic analysis, because ownership of assets and debts just cascades: it makes no difference to the analysis whether you live a long time, or if your children pick up your goods and bads, or their grandchildren do. You could, perhaps, argue that this is a hole in the economics analysis, in which case I’m sure there are scholarly papers discussing this kind of issue.
But in the end, my main reason for arguing for the economic version (with all significant externalities internalised, of course, per std economic theory) is that it is the only approach that has any chance of working. Trying to do it via morality won’t work, but will offer vast scope for special pleading and political interference, all of which is Bad.
[Update: an important question in all of this is, do the gains from CO2 production outweigh the losses? Or, said another way, Are we producing negative wealth?. This was a question I asked yeeeaaarrrsss ago in sci.env, and got no answer. The link points to a paper which suggests that in some cases the answer is that the losses are larger. I don’t know if it is correct.]
Notes
1. There’s a legal distinction worth mentioning here (2018) that I wasn’t aware of, or only dimly,when I first wrote this post, between Malum in se (things bad in themselves, essentially irrespective of the law) and Malum prohibitum (things bad because prohibited by law). Murder is “in se”, smoking, whilst mildly “in se”, is mostly “prohibitum”.
Prompted by 
Dunno yet. I’ll expand on this if I do. For the moment, 
