October 27, 2009

Freak's fact-checking fails on climate change

As a student of economics and statistics, it’s no surprise that I’m a big fan of Freakonomics: A Rogue Economist Explores the Hidden Side of Everything and, consequently, economist Steven Levitt and writer Stephen Dubner. Presenting economic models and statistical techniques in a tractable and entertaining way, Freakonomics had a strong appeal for both the general public and economists alike. However, after reading the bestseller’s sequel, Superfreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance, my appreciation for Levitt and Dubner’s work has dropped a few notches. While Freakonomics did receive some criticism for a few of its particularly controversial conclusions, especially the chapter which connected legalized abortion to lower crime rates, this dissent pales in comparison to the backlash against the blatant inaccuracies about climate change in Superfreakonomics.

“We don’t know with any certainty whether our current path will lead temperatures to rise two degrees or 10,” the book tells us. “Nor do we really know if even a steep rise means an inconvenience or the end of civilization as we know it.” When it comes to science, we don’t know anything with 100 percent certainty, but respected climate projections show that greenhouse gases will heat up the planet by at least two degrees Celsius or Fahrenheit. As statistical modeling improves, new projections show even more severe temperature changes. What’s more, even two degrees of warming will mean low-lying island nations will not survive the rising oceans. Five degrees means 40 percent of the earth’s species face extinction. Illinois will have the heat and drought of a Texas summer in less than 40 years.

The book gets more outlandish from there, jumping right into one of the most dangerous pitfalls in nonfiction writing: citing dubious sources. They reference former Microsoft CTO Nathan Myhrvold to suggest “wind farms are a government subsidy scheme” and “transportation is just not that big of a sector [for emissions].” Wind is subsidized, definitely, but nearly all energy is, and U.S. fossil fuels get double the subsidy dollars of renewable energy sources. Transportation? It creates almost 25 percent of the globe’s carbon dioxide emissions, and more than 26 percent of all the greenhouse gas pollution in the U.S.

In pushing their supposedly cost-effective alternative to emissions cuts—geoengineering 100,000 tons of sunlight-diffusing sulfur dioxide aerosols into the stratosphere each and every year—they cite Ken Caldeira, a Stanford climatologist who studies geoengineering and allegedly supports their solution. According to the book, “his research tells him that carbon dioxide is not the right villain in this fight. ” Unfortunately for them, Dr. Caldeira has called the chapter misleading in many places and incorrect in its characterization of his views. Learn how to quote, guys.

Dr. Caldeira actually supports drastically cutting greenhouse gas emissions, not covering them up. He warns that the sulfur dioxide aerosol scheme would leave ocean acidification unchecked, wiping out big chunks of marine life. It would have completely uncertain long-term effects on the ozone layer, atmosphere, and various ecosystems. However, the only drawback that the book proposes for this geoengineering scheme is that it might be “too simple and too cheap.” Never mind the book’s detailing of the comparatively minor uncertainties in climate modeling.

The rest of the book at least lives up to the standard of Freakonomics for explaining rather dry economic principles in interesting ways. The engrossing prostitution chapter gives good examples of price discrimination, the costs and benefits of middlemen in markets (be it for sex or for a new house), and substitutes and complements. The chapter on suicide bombers? It’s great as an introduction to the basics of indirect costs, selection bias, and econometric models.

Even the “global cooling” chapter has well-written sections on uncertainty and externalities that recall Freakonomics’ excellent explanation of fairly complicated methods and ideas. But the book’s position on climate change is too unsettling to ignore, especially given that the strongest global warming bill yet is working its way through Congress, and international climate negotiators will be meeting in Copenhagen this December. For Levitt and Dubner, adopting the contrarian position may seem fresh (and profitable), but it also does a disservice to America’s fight against the rising costs of climate change and unfairly dismisses the opportunities for transitioning to clean and safe sources of energy.