“What do Al Gore and Mount Pinatubo have in common?” ask the Freakonomics duo Steven Levitt and Stephen Dubner, in their new book SuperFreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance. Their answer: “Al Gore and Pinatubo both suggest a way to cool the planet, albeit with methods whose cost-effectiveness are a universe apart.” Al Gore wants to cool the planet by drastically cutting back the amount of heat-trapping carbon dioxide people are emitting into the atmosphere. In 1991, the Mount Pinatubo volcano in the Philippines cooled the planet when it blasted millions of tons of sulfur particles into the stratosphere where it formed a global haze that lowered average temperatures by about 0.5 degrees Celsius.
In their controversial chapter on global cooling, Levitt and Dubner describe how a bunch of researchers and entrepreneurs at Intellectual Ventures have devised a “garden hose to the sky” method for cooling the planet. The firm, founded by polymath and former Microsoft executive Nathan Myhrvold, proposes the use of an 18-mile hose with helium balloons and pumps every few hundred yards injecting liquefied sulfur dioxide into the stratosphere to mimic the cooling produced by the Pinatubo eruption. The group estimates that setting up five sulfur injection base stations would cost a mere $150 million and cost $100 million per year to operate.
Meanwhile, the costs of deep reductions in carbon dioxide emissions—the strategy currently in vogue—are highly disputed. Global warming alarmists tend to minimize the costs and global warming deniers maximize them (I use the derogatory terms each side calls the other with full malice aforethought). So let’s use as an approximation the latest estimates from British economist Nicholas Stern. Stern, admittedly, inhabits the alarmist camp. He recently asserted that it will take spending 2 percent of global GDP (currently about $64 trillion) to prevent catastrophic climate change. That would amount to spending about $1.2 trillion per year. The money would be spent on developing and deploying a variety of energy efficiency improvements and low carbon energy technologies. That’s the Gore way to cool the planet. Levitt and Dubner conclude by contrasting $250 million versus $1.2 trillion.
Despite their rather breathless presentation of the options for a technical quick fix, these climate engineering schemes are not all that innovative. In fact, similar schemes, including a sulfur sun screen, were outlined in a 1997 article in Reason by physicist and sci-fi writer Greg Benford. In September, the Royal Academy issued a study, Geoengineering the Climate [PDF], evaluating comparable proposals. On November 5, the Science and Technology Committee in the House of Representatives will hold a hearing on the feasibility and risks of climate engineering, including the stratospheric sulfur shield. Clearly, Levitt and Dubner are not making novel proposals, they are popularizing marginalized ideas that have been around for a long time—that's their stock in trade.
Levitt and Dubner acknowledge that the objections to the stratoshield project are “legion,” and indeed they are [PDF]. They note that Myhrvold is not recommending that the stratoshield or other climate engineering schemes be deployed immediately, but that they be “researched and tested so they are ready to use if the worst climate predictions were to come true.” If manmade warming is worse than currently projected, such a shield would also give humanity time to invent and deploy a new no-carbon energy infrastructure.
Yet despite a variety of caveats and cautions, Levitt and Dubner have provoked a firestorm of criticism among ideological environmentalists and their fellow travelers. Why? Because the global warming debate is politicized from top to bottom. Levitt and Dubner breezily stepped into the climate science and policy debate and violated the environmentalist taboo on discussing geoengineering proposals in public.
“The primary reason there has been so little debate about geoengineering amongst climate scientists is concern that such a debate would imply an alternative to reducing the human carbon footprint,” write British climate researchers, Peter Cox, professor of climate system dynamics at the University of Exeter, and Hazel Jeffrey, head of strategic management at the U.K.’s Natural Environment Research Council in Physics World. Or, as Levitt and Dubner acknowledge in their chapter, geoengineering might be seen as “an excuse to pollute,” luring the public into climate change complacency.
In this political fight, accusations of bad faith are the coin of the rhetorical realm. And it doesn’t help that Levitt and Dubner elided over or mischaracterized some research and policy prescriptions. For example, they note that carbon dioxide emissions are being absorbed by seas causing ocean acidification which threatens shellfish and corals, but do not mention that the Pinatubo cooling plans would do nothing to solve that problem. In the policy realm, they cite Harvard economist Martin Weitzman’s argument that the uncertainties surrounding future temperature projections suggest the possibility of catastrophic climate change. However, they fail to note that Weitzman concludes that the remote possibility of total climate disaster justifies spending a lot of money now on efforts to avoid it. And let’s not get into the argument over what recent global temperature trends portend.
In the end, it is not at all surprising that Joe Romm, one of the more apoplectic climate alarmists, who writes the ClimateProgress blog over at the liberal Center for American Progress, dug deep into his rhetorical coffers and accused Levitt and Dubner of bad faith. Stanford University climatologist Ken Caldeira was a participant in the discussions at Intellectual Ventures that Levitt and Dubner report. Caldeira has been seriously researching the implications of geoengineering as a backup plan for cooling the earth for many years. Blogger Romm, in his self-appointed role as enforcer of climate change policy taboos, was horrified that Levitt and Dubner were citing Caldeira in favor geoengineering proposals.
In high dudgeon, Romm apparently emailed Caldeira: “Lines about you like (page 184) 'Yet his research tells him carbon dioxide is not the right villain in this fight' seriously abuse your reputation and your extensive publications and warnings about the threat of ocean acidification.” Romm then solicited Caldeira’s help, explaining, “I want to trash them [Levitt and Dubner] for this insanity and ignorance.” Romm, self-importantly but accurately, added that “my blog is read by everyone in this area, including the media.” He outlined just the sort of thing that he wanted Caldeira to say: “I’d like a quote like ‘The authors of SuperFreakonomics have utterly misrepresented my work,’ plus whatever else you want to say.”
A rattled Caldeira emailed Romm back and complained: “So, yes, my representation in the Superfreakonomics book is damaging to me because it is an inaccurate portrayal of me. The problem is the inaccurate portrayal, not my actions or statements.” Caldeira especially objected that he would never have said carbon dioxide is “not the right villain in this fight.” Romm then published his attempt at debunking Levitt and Dubner. The headline alone reads:
Error-riddled ‘Superfreakonomics’: New book pushes global cooling myths, sheer illogic, and “patent nonsense” – and the primary climatologist it relies on, Ken Caldeira, says “it is an inaccurate portrayal of me” and “misleading” in “many” places.
Romm’s column provoked a flood of condemnations. Levitt and Dubner asked Caldeira what was going on and he responded, “I do think there are a bunch of things in the chapter that give misimpressions.” However, Caldeira also said to other journalists, “I believe the authors to have worked in good faith. They draw different conclusions than I draw from the same facts, but as authors of the book, that is their prerogative.” In any case, a somewhat rueful Caldeira explained, “I was drawn in by Romm and Al Gore’s assistant into critiquing other parts of the chapter. Rather than acting deliberately, I panicked and commented on things that I now wish I would have been silent on. It was obviously a mistake to let myself get drawn into this, and I learned a quick and hard lesson in public relations.” Indeed. Levitt and Dubner say that they will take out the offending “villain” quotation from subsequent editions.
Romm himself mischaracterizes Levitt and Dubner’s chapter as advocating a “geo-engineering-only solution.” Levitt and Dubner make it pretty clear throughout that their Pinatubo cooling proposal is a backup plan, just in case humanity can’t or won’t cut back on its carbon dioxide emissions. For example, Myhrvold notes, “It’s a bit like having fire sprinklers in the building. On the one hand, you should make every effort not to have a fire. But you also need something to fall back on in case the fire occurs.” Myhrvold adds, “It gives you breathing room to move to carbon-free energy sources.”
A year ago, in a roundtable on geoengineering in The Bulletin of the Atomic Scientists, Ken Caldeira argued, “Prudence demands that we consider what we might do if cuts in carbon dioxide emissions prove too little or too late to avoid unacceptable climate damage.” What should we do? “We need a climate engineering research and development plan.” Caldeira warned, “We cannot afford a new period of Lysenkoism and allow political correctness to pollute our scientific judgment. Scientific research and engineering development should be divorced from moral posturing and policy prescription.” He was right then and he’s right now.
Although flawed, in SuperFreakonomics, Levitt and Dubner have done citizens and policymakers a real service by breaking the taboo on discussing the feasibility and risks of climate engineering in public.
Ronald Bailey is Reason magazine's science correspondent. His book Liberation Biology: The Scientific and Moral Case for the Biotech Revolution is now available from Prometheus Books. This column first appeared at Reason.com.