Yet More Superfreakonomics Blogging. Yes. I Know. I Know...
A breakfast companion points out that there seem to be three big differences between Levitt and Dubner on the one hand and we economists who tend to worry about global warming on the other. He further points out that these are all due to the fact that Levitt and Dubner today appear to no longer be thinking like economists. Economists believe that there are always substitutes--alternatives; economists believe that there are always complements--always ways of doing things that reinforce each other, especially in situations of uncertainty in which diversification is especially valuable; economists believe that orders of magnitude are very important and that the right simple numbers are good guides to orders of magnitude;
The first is that we economists see geoengineering as a complement to other measures--as something you research now in addition to clean energy technologies; as important to do because uncertainty is rife and so diversification to reduce risk is much more than usually important; and as something that you do in the future as your other conservation, efficiency, and shift-away-from-open-carbon energy policies take hold--and that (if they work) allow you to do less of other policies. (Though perhaps not all that much less, in all probability: a world with significantly more CO2 and significantly less sunlight and significantly more acid rain would be very different from our current world in a number of ways we do not know understand, some of which might be quite costly.) Dubner and Levitt, by contrast, appear to see them as substitutes--as what we do not in addition but instead of conservation. For Levitt and Dubner, we do geoengineering, and then we don't have to do anything else--that conservation on the one hand and geoengineering on the other are alternative "way[s] to cool the planet, albeit with methods whose cost-effectiveness are a universe apart.
The second is Levitt and Dubner's buying of Nathan Myhrvold's claims that "coal is so cheap that trying to generate electricity without it would be economic suicide" and that "energy consumed by building thousands of new solar plans necessary to replace coal-burning and other power plants would create a huge long-term 'warming debt'." Your standard economist's response to "there are no cost-effective substitutes" is always "you must be joking." Your standard economist's response to the claim that it is very costly to shift the productive structure of an economy from one configuration to another is always "show me the money." Yet that doesn't happen in this case:
Mr. LEVITT: Right. But I just don't--if you look at the history of modern mankind, I think you will be hard pressed to find any particular problem that was serious that was solved by a behavioral change, as opposed to by a technological solution...
That's just not economics: economics is that incentives change, and as incentives change people's behavior changes.
The third is that Levitt and Dubner no longer think like normal economists in looking not just for a number but for the right number relevant to a back-of-the-envelope calculation. For example, they write:
When Al Gore urges the citizenry to sacrifice... the agnostics grumble that human activity accounts for just 2 percent of global carbon-dioxide emissions, with the remainder generated by natural processes like plant decay...
Yoram Bauman questions this:
More Superfreakonomics: I have just seen a PDF of the Superfreakonomics chapter on climate change, and it makes basic mistakes when it says things like “When Al Gore urges the citizenry to sacrifice… the agnostics grumble that human activity accounts for just 2 percent of global carbon-dioxide emissions, with the remainder generated by natural processes like plant decay.”... [Y]es, human generation of CO2 is dwarfed by natural processes like plant decay. But it also shows that natural processes balance each other out: plant decay generates massive amounts of CO2, and plant growth takes in massive amounts of CO2 via photosynthesis. What you’re left with is a completely plausible story in which human activity slowly increases atmospheric concentrations of CO2 from pre-industrial concentrations of about 285ppm (parts per million) to current concentrations of about 385ppm that are going up by about 2ppm per year.
This sort of misleading skepticism exists throughout the chapter, and it does a disservice to climate science, to economists like me who work on climate change, to academic work in general, and to the general public that will have to live with the impacts of climate policy down the road....
Steve Levitt responds:
I don’t understand your comment below. Why does it matter if natural processes are in balance or not? CO2 is CO2! The source doesn’t matter. If we could cut CO2 emissions a little bit overall, whether through natural sources or others, the effect would be the same. It is not saying that cutting human emissions isn’t the right way to do it, but it is a surprising fact and one worth mentioning...
Yoram Bauman tries again:
[Y]ou are ignoring the overall thrust of the chapter, which is terribly misleading. It’s not factually incorrect to write that “agnostics… grumble that human activity accounts for just 2 percent of global carbon-dioxide emissions”, or to give big play to media stories from the 1970s about “global cooling”, or to write that Lowell Wood says that global sea level will rise 1.5 feet by 2100... but all of these statements collectively give a terribly misleading perspective:
- Yes there are agnostics who “grumble that human activity accounts for just 2 percent of global carbon-dioxide emissions”, but this is not a reason to doubt the theory of anthropogenic climate change. The book makes it sound like YOU are among the agnostics, and this is bad....
So that’s my two cents: Your chapter pains me not because it’s factually incorrect but because it clearly gives a misleading impression of the scientific consensus on climate change. I am reminded of your quorum on global warming that your blog colleagues were kind enough to invite me to participate in. There’s nothing factually wrong in there, but it is terribly misleading that the two scientists you quote are BOTH skeptics. What are the odds of that? Probably a billion to one, so my unavoidable conclusion is that you are deliberately trying to cast doubt on the scientific consensus. I don’t mind if you do this in a straightforward way by getting involved in climate research, but to do it via insinuations is in my opinion a disservice to to climate science, to economists like me who work on climate change, to academic work in general, and to the general public that will have to live with the impacts of climate policy down the road...
Steve Bloom chimes in:
The business about the CO2 stocks and flows boils down to an argument from personal incredulity: How could puny man affect a systerm so large? Levitt isn’t that stupid. The only “agnostics” who point to it are those who themselves lack an understanding of the climate system or are actively encouraging misunderstanding by others. It would be one thing if he mentioned it by way of explaining and debunking, but it doesn’t sound as if he does.... I now see that the CO2 point was intentionally framed to mislead and confuse.
And my brain has just exploded:
Excuse me while I pick up stray neuronal clumps from the many different corners of the room...
I mean, Levitt and Dubner’s passage really ought to read:
When Al Gore urges the citizenry to sacrifice... the agnostics grumble that human activity accounts for just 2 percent of global carbon-dioxide emissions, with the remainder generated by natural processes like plant decay. Of course the agnostics are misleadiing you: even though human activity creates just 2% of the flow of emissions, already there is 50% more CO2 in the atmosphere than there would be without human activity...
or:
When Al Gore urges the citizenry to sacrifice... the agnostics grumble that human activity accounts for just 2 percent of global carbon-dioxide emissions, with the remainder generated by natural processes like plant decay. Of course the agnostics are misleadiing you: even though human activity creates just 2% of the flow of emissions, once human-created CO2 is in the atmosphere it takes longer for nature to absorb the nature-created CO2. As a result, already there is 50% more CO2 in the atmosphere than there would be without human activity…
or:
When Al Gore urges the citizenry to sacrifice... the agnostics grumble that human activity accounts for just 2 percent of global carbon-dioxide emissions, with the remainder generated by natural processes like plant decay. Of course the agnostics are misleadiing you: the right way to think about it is that already 1/3 of the CO2 molecules in the atmosphere are the products of human actiivity, and the fraction and amount are growing very rapidly indeed…
Levitt and Dubner structure their passage to say (a) only 2% of emissions are of human origin, and (b) the fact that only 2% of emissions are of human origin is relevant to and supports an “agnostic” position on global warming.
But that is a lie: itt does not support an agnostic position. It is grossly, grossly misleading for Dubner and Levitt to talk about how the relative flows are "a surprising fact and one worth mentioning." They know damned, damned well that what is relevant to the "agnostic" positon are not the flows but rather the stocks. And they know damned, damned well even though only 2% of the new CO2 molecules created are of human origin, a full 30% of the stock of CO2 molecules existing is of human origin--with that percentage climbing every day.
Oh! There’s my right parietal lobe over there under the couch!
Let me give Steve Levitt the last word:
Steven Levitt:
...I do think also that there is something to be said for raising some skepticism about the current climate models and predictions... they are stated and restated as if they are fact, when in practice I suspect, and good scientists agree, that there is enormous uncertainty and things we cannot or at least could not know...
No, let me give [email protected] the last word:
While eco-cultists like Al Gore keep referring to a 6 degree C rise in global temperature as some sort of doomsday scenario, the agnostics grumble that the temperature of the earth is already 287 Kelvin, so we're talking about a mere 2% increase.
I can haz best-seller?
