I offered to give Yoram the last word in our exchange.  Here it is.

P.S. Yoram’s non-fiction graphic novel officially releases on June 5.  That week, with his kind permission, I’ll be posting a few pages from his book.

Let’s focus on the major issues in my exchange with Bryan, which now cover 4 posts. (Here’s post #1, which was Bryan’s review of my Cartoon Introduction to Climate Change, and then here’s #2 and #3. And I promise that after this post I’ll stick to the comments section on this thread!)

1. Climate science basics

Here I’m delighted to report that Bryan and I agree. I asked:

Are you comfortable saying that carbon dioxide is a greenhouse gas? That human emissions of carbon dioxide are raising atmospheric CO2 concentrations? That global temperatures have been increasing over the past century? That humans are partly responsible for those increasing global temperatures? That “it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century”?

The Cartoon Introduction to Climate Change provides my answers to these questions (Yes, Yes, Yes, Yes, and No I’m Not Comfortable Saying This But I Am Comfortable Saying That The Vast Majority Of Scientists Are Convinced), so I’d like to hear what you have to say about them, Bryan. Can you provide answers?

And he did:

My answers on all counts are the same as your answers, Yoram: Yes, Yes, Yes, Yes, and No I’m Not Comfortable Saying This But I Am Comfortable Saying That The Vast Majority Of Scientists Are Convinced.

This is great; thank you Bryan.

But it would have been better for Bryan to own up to this years ago, back when he was lauding Superfreakonomics and calling global warming “instrumental-looking”
and asking “What happens if you regress annual global temperature 1880-2011 on CO2 [and other stuff] like church attendance per capita, the Dow Jones, televisions per capita, etc“?

If more economists like Bryan were upfront about their agreements with basic climate science then I would feel better about not having time to respond to people like David Henderson, who goes to great linguistic lengths in an effort to argue that global temperatures have not been increasing over the past century. Plus I wouldn’t have to jaw-jaw with people in the Comments section or spend my time reviewing the treatment of climate change in economics textbooks. (The books from Mitt Romney’s top economic advisors, Greg Mankiw and Glenn Hubbard, both earned a top grade, so Bryan please tell your neighbors Cowen and Tabarrok that I’m hoping their forthcoming edition can improve on the C+ they earned last time.)

Bottom line: Thanks for acknowledging your comfort level with basic climate science.

2. Geoengineering

My main response is that we appear to be having a communications problem. In my cartoon book, I write that injecting sulfur particles into the atmosphere “won’t stop ocean acidification.” In post #2 of the current back-and-forth that Bryan and I are having, I again bring up ocean acidification and link to a RealClimate article in which scientists discuss some of their concerns about sulfur injections, including that it won’t stop ocean acidification. Here’s Bryan’s response, in post #3: “One of the reasons I read Yoram’s book, by the way, was to search out additional analysis of geoengineering. By my count, he’s now missed two opportunities – his book and his response to my review – to expand my knowledge of the topic.” I’m flattered that you have such high standards for my cartoon books, Bryan, but let me try again: What do you think about ocean acidification?

PS. In addition to our joint communications problem, I think that geoengineering advocates like Bryan have a communications problem of their very own, namely that they tend to oversell their position. This appears in Superfreakonomics, when Levitt and Dubner claim that “perhaps the single best objection” to their garden hose idea is that “it’s too simple and too cheap.” And it happens with Bryan, who starts off writing that “all things considered, geoengineering looks far superior to other policy options on the table” and that “climate activists sorely need to hear… that leading techno-fixes really do look vastly cheaper than abatement” but then ends up writing that “As best as I can gather… [after] I spent a week reading about geoengineering four years ago… [the complaints of critics] seemed weak.” No wonder the general public has anti-smartest-guy-in-the-roombias when it comes to, well, just about everything.

PPS. While I’m at it, let me put a confession on the table. There are many walls that we can bang our heads against, but each of us only has one head. So we need to pick. Jeff Miron’s got drug legalization, Bryan’s got immigration reform, and I’ve got revenue-neutral carbon taxes. Bryan thinks that geoengineering is a low-cost solution to climate change, and I think that revenue-neutral carbon taxes is a low-cost solution to climate change.

Bottom line: I’m going to continue working on revenue-neutral carbon taxes, especially if geoengineering folks keep failing to address ocean acidification and all these other concerns from climate scientists.

3. Cost-benefit analysis

I think that trying to use CBA for climate change is like trying to use GPS in a cave: great idea, it just doesn’t work very well. Bryan thinks we need to try–perhaps because of a philosophical belief that CBA always passes CBA??–and he “immediately picture[s] multiple variants on the Wheat and Chessboard Problem” to convey issues regarding discount rates.

I hate to play the “because I’m the Mom” card, but look: I’ve now written three cartoon books, and that’s three more than Bryan has written. (I do like his  animated videos though.) And I feel pretty comfortable saying that the Wheat and Chessboard Problem is a lousy fit for cartoon books. (Animated video, yes. Cartoon books, no.) And I feel very comfortable saying that a Cartoon Climate Change book that tried to tackle CBA in a meaningful way would not have much room for anything else. (Remember that Cartoon Micro spent a whole chapter on the basics of discounting, and a whole chapter on the basics of expected value; the long-time-horizon and fat-tail issues with climate change are considerably more complicated, so I’d peg that at 4 chapters already, with a complete treatment taking most if not all of a 16-chapter cartoon book.)

Bottom line: Why does my book not spend much time on CBA? Because I’m the Mom. You go write a cartoon book,Bryan–my psychotherapist tells me you really really want to!–and then we can come back to this.

4. Insurance

Bryan says that “Costco.com sells a year’s supply of dehydrated food for $1499.99” and ask me if I’ve bought it. The answer is No… because it doesn’t include Cougar Jim’s Freeze Dried Water!

On a serious note, I’ll admit–I’m not ashamed!–that in the days before Y2K I went out and bought a few bags of ice and some extra supplies. And even now we try to keep a 3-dayemergency supply of food in the house, per Three Days Three Ways. (Visit ready.gov and think about whether you should too.)

Bottom line: Low probability outcomes that are catastrophic really is a pretty good focal point for insurance. Whether you can get insurance at a reasonable price is a good second-round question–as are concerns about whether your dehydrated food would last much more than a week before somebody with a gun overcame their reverence for private property rights and came for it–but happily for climate change we’ve got revenue-neutral carbon taxes.

5. Comparative advantage

This is actually a new addition to our list, but I can’t resist because Bryan keeps harpingon it. So here’s a question for you, Bryan: In Superfreakonomics, Nathan Myrvold is introduced as somebody who wants to be “every kind of scientist”, as being “so polymathic as to make an everyday polymath tremble with shame.” Did this set off alarm bells for you? It did for me, so I wasn’t surprised to learn that Myrvold was wrong in writing that “the problem with solar cells is that they’re black.” You, on the other hand, didn’t express any concerns about Myrvold, and neither did Levitt. Perhaps there some new kind of bias here that’s worth examining?

Bottom line: You are clearly a very kind person, Bryan–for example, you post my rants on your blog, and I’m grateful for that–but in future you should be less kind to people you
agree with.