Jim Manzi, with whom I have debated warming policy responses before, has a problem with The Washington Post‘s coverage of new studies on climate change. He writes:

The premise of the story by Juliet Eilperin is well-expressed by its headline: “Carbon Output Must Near Zero To Avert Danger, New Studies Say”. Eilperin prominently quotes Carnegie Institution senior scientist Ken Caldeira, co-author of one of the studies promoted by the article, who says: “The question is, what if we don’t want the Earth to warm anymore?” Well, that’s a question, but it’s certainly not the question, and is not even a very good question. I think a much better question might be something like “What are the costs versus benefits of reducing emissions to avoid warming?”

The article never addresses this question, and instead elides between a battery of technical experts asserting that carbon emissions create problems, and interested political actors saying “common sense is that we would not let the planet be destroyed”.

What’s so funny is that Eilperin never seems to be willing do the work to pick up the trail of breadcrumbs that all her interviewees leave behind them. She writes that “Most scientists warn that a temperature rise of 2 degrees Celsius (3.6 degrees Fahrenheit) could have serious consequences.” Really — how serious? Well, according to the U.N. IPCC a 4C increase — twice this amount — would reduce global economic output by 1 to 5 percent. Oh yeah, that’s in the world of the 22nd century which is expected to have per capita consumption of something like $40,000 per year versus our current consumption of about $6,600 per year. So we are condemning future generations to be only 5.7 times richer than us, rather than 6 times richer.

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Now, the intergenerational questions are difficult ones to answer. The bottom line is, most of us living today will experience some bad warming effects, but those effects will pale next to what future generations will face. The question then becomes, how much should we care about those living 100 years from now? What about 500 years from now?

So, it’s quite possible that the consumption loss from warming to those living in 2100 might not be all that significant. But it strikes me as odd that Jim doesn’t appear concerned about the emissions impact of a world with per capita consumption seven times larger than at present, under a non-demand reduction scenario. Is it all good for our richer great-grandchildren to have a slight consumption loss to warming if their great-grandchildren inherit an uninhabitable planet? It would be a bit more honest for him to say that, look, he doesn’t want to tax himself to cut down on carbon because the people living in 200 years will be so stinking rich that they can handle anything, up to and including a planet that cannot support life as we know it.

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The only way Manzi’s point of view is at all important is if emissions reduction measures are costly. Maybe they are. I suspect they’re far less costly than he believes. The problem is, we won’t know until we create some mechanism for pricing carbon. I’ve said this before, and I’ll say it again: we know that carbon emissions generate negative outcomes for society as a whole. We know that people will therefore emit way too much carbon unless they are exposed, at least a little bit, to the price of carbon in their daily consumption activities. Arguing that consumers should not be exposed to carbon costs at all is tantamount to declaring oneself a warming skeptic. It’s silly to pretend there is a problem, or to argue that research subsidies are needed, while simultaneously saying that consumers should be entirely immunized from the carbon content of consumption choices.

Markets are incredibly good at optimizing given constraints. In order to get those markets optimizing in a carbonless fashion, there have to be price signals. Jim Manzi doesn’t think there should be any carbon price signals. This is because he thinks the market response will be too costly. Of course, if the market response is too costly, we could get rid of the price signals and try something different. Jim Manzi thinks that we won’t get rid of the price signals if they’re too costly, because it’s hard to get rid of taxes, despite the fact that everyone will want very much to get rid of them, because they’re so costly. If they aren’t costly, then everything is great, but we can’t risk that, now can we?

I used to think that it was a good thing, on net, for Jim to be out there arguing in this way, because hey, at least he’s not another conservative denialist. I’m not so sure anymore.