Chapter 1 starts with the Chelyabinsk meteor and is edging towards the idea of taking sensible precautions in the face of unknown potential disasters. We learn that "many observers" regards GW of more than 2 oC as potentially leading to "catastrophe" but that economists struggle to understand that term, without a dollar value: 10% of GDP? 50%? What? Then we segue onto the familiar-to-us-all problems of dealing with GW: it is global; slow; irreversible; and plagued by uncertainties. Fat tails get a mention, but we'll come back to them later. Time to quibble: Fourier didn't discover the GHG effects of CO2 at any time let alone in 1824 as any fule kno. The book has references, but they're all tucked away into the back to avoid scaring the horses, so you have to keep flipping around to find out what is well reffed and what isn't. They correctly point out that the solution to GW is Pigouvian taxes4; and discuss why we can and can't actually do anything.
Chapter 2 is a series of definitions, sort of, or perhaps very brief discussions of relevant points; but e.g. reducing the history of climate science to 4 bullet points is too brief; this is part of the awkwardness of the book's target-audience-point.
Chapter 3 is about "fat tails" and is I think... hmmm, well, let's say "overly pessimistic". We're arguing about the value of Climate Sensitivity, and hence the expected warming for 2x CO21. Certainly the values they choose are higher than AR6 gives. I think they'd like to be talking about Weitzman's Dismal Theorem but they back away from it. Tol has stuff to say, too. [Aside: they use the familiar idea that people insure against large improbable risks. But I don't think this analogy helps them, quite the reverse: the point is, that people do choose to run these risks: they don't do absolutely everything possible to avoid them; instead they insure. We now return you to...] There's familiar stuff about DICE damage functions and related matters. There's discussion of whether damage functions should affect rates rather than levels, and so on. What there isn't is (as Tol notes) is any discussion as to whether flailing around with climate policy might leave us overall poorer. In the end, they go for "it is all too complex; let's use $40/ton" which is fine by me7. On discount rates, I think I'm going to rely on my A review of a Review of The Stern Review on the Economics of Climate Change which I think is very much the same stuff. There's a brief (and erroneous) discussion of the analogy of an asteroid-heading-towards-Earth-in-a-century3. Some bits have got slightly out of date: he bemoans - well, as I did - the ETS because the carbon price is too low - but it isn't any more.
Chapter 4: willful blindness. The debate about whether to act on GW should be over, they say, and even on how to act; the question is how high should the price be? While I would love to believe that, it is not true5. A majority of economists would accept it, but not a majority of pols, and not even a majority of scientists - as for the general public, they haven't even thought of the question. Just read the bloody comments on any of my posts on carbon taxes. They return to $40/t, but are then forced to confront a problem: according their analysis, the risk-of-catastrophe is quite high, let us say 10%, and for that $40 is a paltry price... should it not be $400, or $4000, to prevent catastrophe? This analysis spirals out of control as JA noted and fundamentally goes nowhere, and we move on to the next chapter, geoengineering.
Chapter 5: geoengineering, or rather, not (see-also my Reflecting Sunlight). Anyone talking about GW has to talk themselves out of geoengineering, because it is cheap. They point out all the obvious problems - not a full solution, what if we suddenly stop, winners and losers, governance, ocean acidifcation, blah blah the usual stuff. I think their conclusion insofar as they have one is weakly in favour of research8; I'm rather more strongly so although TBH I think it is likely doomed because of the screachers. Notice that some of their objections (geoeng will cool; some people might like it warmer) are dumb, because exactly the same objections exist to halting CO2 increases or CO2 capture; and their distinction between active and passive is I think spurious.
Chapter 6: for no obvious reason they have another chapter on geoeng, but don't really say anything else. Also, they're desperately focussed on reflecting sublight and barely a word and no detail on ocean iron fertilisation. Are they embarassed because as economists they're unable to recommend the cheap solution?
Chapter 7: what to do? This is all worthily sensible and makes all the obvious suggestions. Except... they're all, like everyone else's, somewhat superficial. Suggesting that we help educate our citizenry to have better ideas is perhaps too slow. Given that most of the solution is likely better solar, better wind, electric cars, perhaps they could encourage people to help this effort? Or, they could adopt my solution6.
1. Yes, 2x is arbitrary and CO2 doesn't stop at 2x if you keep emitting; but we have to concretise the discussion somehow, and we shouldn't care too much about post 2100.
3. What should you do if your observations and calculations suggest that a large asteroid will hit the Earth in a century or so? Not much. Improve your observations; re-check your calculations; perhaps boost research into rockets. But instituting a crash programme of rocket building would be dumb. To make that more obvious, consider what if, a century ago, people had discovered an asteroid heading our way in two centuries.
4. Or should be. Increasingly, though, it is looking more and more likely that we'll get a somewhat less efficient transition: wind and solar will just become cheaper, we'll swap to that, and there will be a tremenous froth of pointless nonsense on top.
5. Thus their chapter title is self-referential, tee hee.
6. Which is using my native intellect and high quality education to... write software. And, of course, helpful blogs: if only anyone would listen. This of course is nothing to do with my desire for money but because I'm inclined to trust the market to find the most useful use for me; but happy co-incidence, that's whoever will pay me most.
7. Most people in favour of carbon taxes end up about there; like most people interested in CS end up at 3 oC or thereabouts; that doesn't mean that all the words wrapped around it are worthless, but I think if I was a general reader I'd be disappointed: so many quibbles, ideas, qualifications, and we just shrug and pick a number.
* The Cost of Insuring Expensive Waterfront Homes Is About to Skyrocket - if only. If we (well, OK, not me, those funny USAnians and their disfucntional govt) can't even get simple things like this right, what hope for harder stuff?
* What does "local control" actually mean? by Scott Sumner
* Whither Tartaria? - ACX
* Rational Irrationality in High Places by Bryan Caplan; on Pinker: It’s really only with I think the Enlightenment more or less that the idea that all of our beliefs should be put in the reality zone, should be scrutinized for whether they’re true or false. It’s actually in human history a pretty exotic belief. I think it’s a good belief, a good commitment, but it doesn’t come naturally to us.