In case you missed this in the daily links. From Paul Krugman:
Gambling with Civilization, by Paul Krugman, NYRB [Review of The Climate Casino: Risk, Uncertainty, and Economics for a Warming World, by William D. Nordhaus]:
1. Forty years ago a brilliant young Yale economist named William Nordhaus published a landmark paper, “The Allocation of Energy Resources,” that opened new frontiers in economic analysis.  Nordhaus argued that to think clearly about the economics of exhaustible resources like oil and coal, it was necessary to look far into the future, to assess their value as they become more scarce—and that this look into the future necessarily involved considering not just available resources and expected future economic growth, but likely future technologies as well. Moreover, he developed a method for incorporating all of this information—resource estimates, long-run economic forecasts, and engineers’ best guesses about the costs of future technologies—into a quantitative model of energy prices over the long term.
The resource and engineering data for Nordhaus’s paper were for the most part compiled by his research assistant, a twenty-year-old undergraduate... It was an invaluable apprenticeship. My reasons for bringing up this bit of intellectual history, however, go beyond personal disclosure—although readers of this review should know that Bill Nordhaus was my first professional mentor. For if one looks back at “The Allocation of Energy Resources,” one learns two crucial lessons. First, predictions are hard, especially about the distant future. Second, sometimes such predictions must be made nonetheless.
Looking back at “Allocation” after four decades, what’s striking is how wrong the technical experts were about future technologies. For many years all their errors seemed to have been on the side of overoptimism, especially on oil production and nuclear power. More recently, the surprises have come on the other side, with fracking having the biggest immediate impact on markets, but with the growing competitiveness of wind and solar power—neither of which figured in “Allocation” at all—perhaps the more fundamental news. For what it’s worth, current oil prices, adjusted for overall inflation, are about twice Nordhaus’s prediction, while coal and especially natural gas prices are well below his baseline.
So the future is uncertain, a reality acknowledged in the title of Nordhaus’s new book, The Climate Casino: Risk, Uncertainty, and Economics for a Warming World. Yet decisions must be made taking the future—and sometimes the very long-term future—into account. ... And as Nordhaus emphasizes, although perhaps not as strongly as some would like, when it comes to climate change uncertainty strengthens, not weakens, the case for action now.
Yet while uncertainty cannot be banished from the issue of global warming, one can and should make the best predictions possible. Following his work on energy futures, Nordhaus became a pioneer in the development of “integrated assessment models” (IAMs), which try to pull together what we know about two systems—the economy and the climate—map out their interactions, and let us do cost-benefit analysis of alternative policies.  At one level The Climate Casino is an effort to popularize the results of IAMs and their implications. But it is also, of course, a call for action. I’ll ask later in this review whether that call has much chance of succeeding. ...[continue]...