Yoram Bauman, co-author of The Cartoon Introduction to Climate Change, asked to respond to my review.  I’m about to go to my parents’ golden anniversary party, so I probably won’t respond until late next week.

Here’s Yoram:



Response to Bryan
Caplan’s review of Cartoon Climate Change

Thanks to Bryan Caplan for
his review
of my Cartoon Introduction
to Climate Change
, and double thanks if he cross-posts this response on
his blog (although it may mean I have to tweak my jokes about how I’ve been banned
by a libertarian blog

As with most academics,
Bryan keeps his words of praise to a minimum and instead focuses on criticisms.
I will do the same (!) but let’s begin with what appears to be the good news:
Bryan says “there is much to like” in the book, that he
“genuinely liked” it, and that he was “entertained and

On second thought, however,
this “good news” is remarkably vague, and I am worried that it is
intentionally so. It is this worry—and not narcissism—that leads me to ask:
What exactly did Bryan like in the book? What was he enlightened about? And is
he hiding something that he doesn’t want to tell his readers, or perhaps even
something that he doesn’t want to admit to himself?

I ask this because Bryan
exhibits all of the symptoms of a global-warming-related malady known as
Selective Scientific Ignorance. I did a Google search for statements that Bryan
has made about climate science, and the most encouraging things I was able to
come up with were (1) a post from 2007 about how he believes in “moderate
global warming” because
global warming skeptics aren’t taking bets
and (2) a reference
to a 2007 survey of climate scientists. (BTW, here’s the 2013 survey update.)
But I also found his review
of Superfreakonomics
, a review that calls out as a highlight the
book’s “surprisingly skeptical look at global warming”. (For a less
flattering view, see my
back-and-forth with Steve Levitt
and/or this classic
that ends with climatologist Raymond Pierrehumbert, Levitt’s colleague
at the University of Chicago, giving Levitt the Google Map directions to his
office.) And I found his review
of my Cartoon Macro book
, in which he somehow manages to focus on
the wonders of his hero, Julian Simon—“For whom my
son Simon Caplan is named
“—while ignoring Simon’s failed guess that
“global warming is likely to be simply another transient concern, barely
worthy of consideration ten years from now.” (Simon wrote that in 1996).

Why do I call this
Selective Scientific Ignorance? Because it doesn’t stop Bryan from pontificating
about other matters, like geoengineering, about which he writes elsewhere that “all
things considered
, geoengineering looks far superior to other policy
options on the table.” More on this below, but, gosh, is this person who
has considered all things really the same person who says that his
“understanding of natural science is very
“? More on geoengineering below, but I for one am eager to hear
what Bryan has to say about ocean acidification, or about the impact of massive
atmospheric sulfur injections on global weather patterns.

Like Bryan, I’m not a
natural scientist, and I’m not an epidemiologist either. But I’m comfortable
saying things like “smoking causes cancer” instead of dog-whistle
baloney statements like “some scientists say that smoking causes
cancer” or “nobody is making bets that smoking doesn’t cause
cancer” or (holy cow, Bryan!) “Key question: Does smoking really
dominate if you regress lung cancer deaths over the past century with cigarette
consumption and also placebo
variables like church attendance per capita, the Dow Jones, televisions per
capita, etc.
?” (More on this from Bryan here;
don’t miss his “I wish experts would tell me” plea at the end that makes
me wonder if he needs Google Maps too.)

I could go on, but I’ll
just call the question. Bryan, you said that you were
“enlightened” by the book, so what exactly did you learn from it?
More importantly, what are you willing to publicly acknowledge about climate
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?
Or are you just going to continue to tolerate in yourself a lazy acquiescence
that saves you the trouble of confronting your own views, of confronting
politicians like Marco
“our climate is always changing” Rubio
, and of confronting fellow
economists like Steve Levitt who write misleading
about how “When Al Gore urges the citizenry to sacrifice… the
agnostics grumble that human activity accounts for just 2 percent of global
carbon-dioxide emissions”? (Now that you’ve read my book you know why
that’s misleading baloney, right?)

Okay, now that that’s out
of the way, let’s proceed to the numbered points of attack in Bryan’s original
review. (And I hope that everyone will keep in mind that Bryan “genuinely
liked” the book!)

1) “We can use
cost-benefit analysis [CBA] to put climate change in perspective.”

It’s much harder than you think, Bryan. For example, read Pindyck
, who argues that risks from climate change should be thought about as
similar to the Cold War risks of thermonuclear conflict between the US and the
Soviets. (Would you advocate the use of CBA to “put the Cuban Missile
Crisis in perspective”?)

Moreover, there are four
independent reasons that the waters for CBA are muddy. Reason #1 is that CBA
has trouble dealing with uncertainty: if there’s a (say) 1% chance that climate
change will be catastrophic and a 99% chance that it will be no big deal, how
do you account for that in CBA? I don’t think anybody who knows the St
Petersburg Paradox
(and Marty Weitzman’s related work on “fat
) has a good answer here. Reason #2 is that CBA has trouble
dealing with inter-generational issues involving the distant future. (More on
this below.) Reason #3 is that CBA has trouble dealing with intra-generational
issues, e.g., the likelihood that climate change will be harder for Bagladeshis
than for Americans. (And no, I’m not buying into any “hypothetical
compensation schemes”.) Reason #4 is that CBA has trouble dealing with
non-market valuation on the massive scale that we’re talking about here; a good
rule of thumb is that CBA is good for engineering but less good for

Put those four reasons
together and it’s clear to me that you’re opening a can of worms for no good
reason. That’s fine in a textbook—it’s often the point of textbooks!—but in
a cartoon book there’s no space.

2) “Cost-benefit
analysis is sensitive to discount rates.”
See above, but more
importantly I think you’re being too technical and (like most discount-rate
fetishists of all political persuasions) missing the real questions. The real
questions are about the wealth of future generations relative to the current
generation, and about their preferences. Unfortunately it’s pretty hard to
answer these questions—especially, as we note in the book, about the distant
future—so when you ask the hypothetical Kaldor-Hicks question that underlies
discount rates (How much money would we have to set aside now to compensate
future generations for climate damages?) you end up in the can of worms again.

3) “Insurance is
NOT a no-brainer.”
You’re absolutely right that buying an extended
warranty for a toaster is a bad idea, but the cartoon book repeatedly
emphasizes low probability outcomes that are catastrophic, which is a
pretty good focal point for insurance. Of course, as you point out, the
attractiveness of insurance also depends on the cost. I agree with you that the
cartoon book lacks some subtlety on this point, and if I’d had twice as many
pages I would have done better. Instead we get what I think is a reasonable
summary given the space available: “If we give up a small piece of cake…
we can get peace of mind.”

4) “Leading
techno-fixes really do look vastly cheaper than abatement.”
Ah yes,
here we are, back to Mr. All Things Considered. Unfortunately, I don’t really
have any more fireworks to set off because I am no expert on geoengineering. I
certainly have nothing against considering it. But I also know (and you should
too) that the “costs” of pumping SO2 into the upper atmosphere are
not limited to the dollar costs of pumping
the stuff up there
. So I’m concerned that geoengineering is being
oversold by people like you who haven’t thought it all the way through and have
a “What,
me worry?”
approach to the risks of climate change. PS. At the very
least we should all be able to agree that Levitt and Dubner were way off in
claiming (in Superfreakonomics) that “perhaps the single best
objection” to their garden hose idea was that “it’s too simple and
too cheap.” Way off. Yes?

5) “National
emissions regulations can have perverse global effects.”
Here I think
you’re making a mountain out of a molehill. True, national efforts to reduce
(say) oil consumption would shift the global demand curve to the left, which
would lead to a new equilibrium and (provided the supply curve is not perfectly
elastic) a smaller drop in consumption than a naive analysis would suggest.
But… why is this perverse? (It just sounds like economics to me!) What is
perverse in my view is that you fail to note that the book emphasizes the
importance of international action, e.g., with the division of the world
population into “5 Chinas”.

6) “Expressive
voting is a big deal.”
I know this is one of your hobby-horses, Bryan,
but I’m afraid you haven’t convinced me that this is a big deal. Look at the
climate legislation that’s out there: the British
Columbia carbon tax
, the (failed to clear the Senate) Waxman-Markey
, California’s AB 32 cap-and-trade system, etc. It all looks pretty
substantive to me. Do we really need to get into the psychology of voting,
whether from greens who obsess about recycling or from free-market folks who
obsess about the hockey-stick illusion? The answer—or at least my answer,
especially in a cartoon book
that is supposed to cover the basics of climate change in 200 short pages—is