Cartoon Introduction to Climate Change: Rejoinder to Yoram Bauman
By Bryan Caplan
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
You should stop worrying, Yoram. I thought you did a good overall job, but due to the graphic format, my favorite parts were hard to describe in words alone. I wanted to scan a few of my favorite pages, but I was worried about copyright. If you get me permission from your publisher to post two or three of my favorite pages, I will.
I ask this because Bryan
exhibits all of the symptoms of a global-warming-related malady known as
Selective Scientific Ignorance…
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
Like most bloggers and almost all journalists, I often discuss areas where I’m not qualified to write an academic literature review. Climate change is one such topic – and I think I’ve been forthcoming about my limitations. In normal English, “all
things considered” does not literally mean that the speaker has
“considered all things.” It’s much closer to “As best as I can
gather…” than “Given my encyclopedic knowledge…”
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.
The sum of what I ever knew: I spent a week reading about geoengineering four years ago. I set up a lunch for my closest hard science friend to cross-examine a leading geoengineering advocate. And I participated in a conference on the topic. My take-away: I’d given critics of geoengineering multiple opportunities to criticize the idea, and their complaints seemed weak. Yoram may ridicule my efforts, but it seems like an unusually diligent attempt to form an opinion about an issue I don’t personally research.
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.
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 find Google Scholar a better way to locate research than Google Maps. And I did search Google Scholar before posting my regression query. I found nothing directly on point, and as far as I recall none of the comments directed me to anything better.
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
science? 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
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?
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.
Or are you just going to continue to tolerate in yourself a lazy acquiescence
that saves you the trouble of confronting your own views…
I’d think the “lazy” approach would be to uncritically embrace the expert consensus. Instead, I’m making an effort to reconcile several views in tension with one another. By default, I accept the scientific consensus. Two of my other defaults, however, are to mistrust environmentalists and doom-sayers generally. My tentative reconciliation of these views is that the standard story of climate change is qualitatively right, but quantitatively overblown.
Furthermore, the prudent Bayesian response to Yoram’s book is to think the dangers are a little more overblown than I initially thought. Why? Because I expected more from Yoram.
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
2013, 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
I’d much rather learn about the best CBA on global warming, followed by some discussion of the weaknesses, than hear “it’s harder than I think” or read blanket methodological objections. When you don’t even try to present the best CBA, I raise my probability that the best CBA shows that climate change is not a big deal.
(Would you advocate the use of CBA to “put the Cuban Missile
Crisis in perspective”?)
CBA of the Cuban Missile Crisis would have been great, yes. I’m also a big fan of CBA of the War on Terror.
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
tails”) has a good answer here.
I’d probably start by putting in a 1% chance of GDP falling to zero forever, and see what that looks like. Or subtract 1% times expected deaths given a catastrophe times the usual value of life. Almost anything would be more convincing than pre-emptively giving up.
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
Then do standard CBA, and supplement it with a distributional breakdown. Furthermore, if you’re willing to try to get the world to drastically curb impending carbon emissions, what’s so quixotic about international compensation proposals – possibly in the form of more open immigration policy?
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.
Most of your claims are subject to analogous caveats. You usually ably handled the problem by hitting the high points, then briefly acknowledging complexities. Why didn’t you do the same for CBA?
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.
No, it’s a terrible focal point for insurance. Most people fail to insure against many low-probability catastrophic events – and you probably don’t want to call them fools. Just one example: Costco.com sells a year’s supply of dehydrated food for $1499.99. This product provides excellent insurance against a long list of natural and man-made disasters. Question: Have you bought it? If not, why not? The same goes for what you drive (probably not the safest car), where you live (probably not the safest neighborhood in your area, much less the country or world), where you travel, who you sleep with, and so on. Low-probability catastrophes lurk around every corner, but the standard response seems to be, “Until I see concrete dangers, I’ll take my chances.”
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.”
That’s a deeply unreasonable summary of your own position! If the world capped carbon emissions at 150% of their current level, would Yoram Bauman really have “peace of mind” about the state of the planet in 2100? Do you really think you’re going to get stricter cuts than that? And of course without CBA, it’s very unclear whether we are paying “a small piece of cake,” or delaying the modernization of the Third World by decades.
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.
I can easily understand why this issue might not be worth your time… if you weren’t an environmental economist writing a whole book about climate change. But if Yoram Bauman isn’t qualified to weigh the cost-effectiveness of geoengineering relative to emissions reductions, who is? Call me old-fashioned, but where I come from reviewers request information and authors supply it, not the other way around.
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”.
Maybe I am making a mountain out of a molehill. Maybe you’re making a molehill out of a mountain. This is just the kind of issue an applied environmental economist such as yourself is trained to resolve. Yet I don’t know any more about it than I did before I started your book.
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
bill, 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?
I’m hardly the only person worried that “feel-good” attitudes make environmental policy more costly and less effective. Check out Alan Blinder’s chapter on tradeable pollution permits in Hard Heads, Soft Hearts. You’ve taught environmental economics. Have you really failed to encounter non-economists – including environmental activists – who reject the whole economic approach as offensive?
I admire Yoram’s urge to convert people who don’t already fully agree with him. After all, “Never preach to the choir” is one of my seven guidelines for writing worthy non-fiction. False modesty aside, though, I’m one of the best partially unconverted readers Yoram is likely to find. We’re both economists, we both respect scientific consensus, and we both love the graphic format. Patiently address my specific doubts, and I will listen.