SuperFreakonomics: Global Cooling ?  

The Stoat has a look at some strange climate skepticism being promoted by the professional contrarians responsible for "Freakonomics" (filed under the heading "genral tripe") - SuperFreakonomics: Global Cooling (and some other stuff)?.

I liked Freakonomics, so I'm a bit sad to see the (inevitable) sequel being so hopelessly wrong. Probably this is a case of the old rule: whenever you see people write about stuff you know, they get it wrong. Joe Romm has a fairly characteristic attack; and just for a change I'll agree with him; though he chooses odd bits to assault. It looks like the "global cooling" junk is just one chapter, but of course it is the only one I'll pay any attention to.

Diagnosis, in brief: (1) they write about stuff they clearly don't understand (2) they pick a catchy reverse-common-wisdom nugget as a headliner without the having the slightest interest in whether it is true or not (mind you, plenty of more respectable folk do the same) (3) they pick an expert to talk to, but since they don't have a clue about the subject they don't know how to pick a good expert, or even understand what the expert says (4) there is a grain of sense in there, but so badly wrapped in trash it is nearly unfindable.

The entire piece is riddled with errors. Reading it all would be tedious. So, before reading it in detail I decided to set myself a target of 10 major errors and then stop. Kindly, Romm has provided a PDF of the offending chapter, so you can play along at home.

The folks at RealClimate are aghast at the pseudo-economists claim that a form of geoengineering (the "sulphates in the upper atmosphere" mad-scientist's experiment) would be the most cost effective way to "solve" global warming - Why Levitt and Dubner like geo-engineering and why they are wrong.

The geo-engineering option that is being talked about here is the addition of SO2 to the stratosphere where it oxidises to SO4 (sulphate) aerosols which, since they are reflective, reduce the amount of sunlight reaching the ground. The zeroth order demonstration of this possibility is shown by the response of the climate to the eruption of Mt. Pinatubo in 1991 which caused a maximum 0.5ºC cooling a year or so later. Under business-as-usual scenarios, the radiative forcing we can expect from increasing CO2 by the end of the century are on the order of 4 to 8 W/m2 – requiring the equivalent to one to two Pinatubo’s every year if this kind of geo-engineering was the only response. And of course, you couldn’t stop until CO2 levels came back down (hundreds, if not thousands of years later) without hugely disruptive and rapid temperature rises. As Deltoid neatly puts it: “What could possibly go wrong?”.

The answer is plenty. Alan Robock discussed some of the issues here the last time this came up (umm… weeks ago). The basic issues over and above the costs of delivering the SO2 to the stratosphere are that a) once started you can’t stop without much more serious consequences so you are setting up a multi-centennial commitment to continually increasing spending (of course, if you want to stop because of huge disruption that geo-engineering might be causing, then you are pretty much toast), b) there would be a huge need for increased monitoring from the ground and space, c) who would be responsible for any unanticipated or anticipated side effects and how much would that cost?, and d) who decides when, where and how much this is used. For point ‘d’, consider how difficult it is now to come up with an international agreement on reducing emissions and then ponder the additional issues involved if India or China are concerned that geo-engineering will cause a persistent failure of the monsoon? None of these issues are trivial or cheap to deal with, and yet few are being accounted for in most popular discussions of the issue (including the chapter we are discussing here).

Tim Lambert also has a few words to say on the topic - Underwhelming response from Superfreakonomics authors.

Myhrvold finishes with:

The point of the chapter in SuperFreakonomics is that geoengineering might be good insurance in case we don't get global warming under control.

No, it isn't. The point they are trying to make is that geoengineering is a more cost-effective solution than mitigation. Which is wrong. It might be cheaper, but you don't get the same result.