Given Hansen's recent work, Lomborg's insistence that "all models clearly show both Greenland and Antarctica making small contributions [to sea level rise] over the next century" is silly. Similarly quaint is his claim that Antarctica is a region where "little or no surface melting occurs." Earlier this year, NASA found that California-size lakes formed on the continent's surface in 2005.
Lomborg's focus on a single, midrange number for global temperature increase is paralleled by his insistence that Kyoto-level controls, with the U.S. participating, would have cost the world $180 billion per year. Kyoto mandated a 7 percent reduction in emissions by 2010, and the European countries that are complying with the treaty have done so by placing a cap on emissions from cars and power plants. To get under the cap, industries have to invest in new, cleaner technologies, and to the extent that this increases the cost of travel or power, these higher prices can generate a reduction in the rate of economic growth. This in turn might lead to a small percentage drop in the level of global GDP at the end of each year -- Lomborg's measured cost of Kyoto.
Yet here again he imagines a consensus that does not exist. Yale economist Robert Repetto's well-known review of 16 cost studies concluded that the estimated GDP impact of Kyoto-level controls ranged from the relatively small negative effects that concern Lomborg, to results that were also small, but positive. Reducing emissions might actually spur economic growth by, among other reasons, increasing global energy efficiency.
Lomborg manufactures yet another alleged consensus among economists regarding benefit-cost analyses of carbon controls: "all macroeconomic models show they are poor investments." This is wrong. Several benefit-cost analyses -- including those of William Cline and Frank Ackerman -- have supported serious near-term caps on carbon.
Lomborg is forced to acknowledge, and try to debunk, the most recent counterexample: the high-profile Stern report from the U.K. Lomborg refers frequently to four economic Nobel laureates who agree with his position that carbon controls are too expensive. But professional opinion is far from monolithic. Stern's analysis is part of an ongoing debate among economists -- particularly on the choice of discount rate, a critical parameter that drives the results of all the benefit-cost models. The discount rate determines how much weight the models give to benefits (whether higher GDP or lower global temperatures) that occur in the future.
Lomborg's preferred models choose a high discount rate of 6 percent. This favors reaping GDP benefits soon, while paying surprisingly little attention to long-run climate damages. The reasoning? Those early GDP increases can be productively reinvested and enrich future generations. By contrast, Stern picks a low discount rate of 1.4 percent, asserting on moral grounds that any early GDP gains should be weighed against later climate damages more or less equally. His model worries less about foregone investment and growth opportunities, should climate control efforts noticeably lower GDP over the next few decades.
In his review of the Stern report, Harvard's Marty Weitzman shows that -- irrespective of the moral case -- both Stern's and Lomborg's preferred discount rate can be well justified on theoretical grounds. In the end, both Weitzman and Nobel laureate Ken Arrow argue that Stern might be right (though for the wrong reasons). And two other Nobel winners, Joseph Stiglitz and George Akerlof, and dozens of serious researchers support strong, near-term caps on global warming pollution.
One glaring example: Lomborg frequently cites the Kyoto cost estimates of Yale economist William Nordhaus. And yet, writing in Science, Nordhaus supported Kyoto as a global insurance policy, calling it a "useful if expensive guinea pig." He continued: "It is hard to see why the United States should not join with other countries" in pursuing this important experiment in building the international institutions that can deal with global warming.
As in his previous book, Lomborg cherry-picks the evidence to manufacture both a scientific and economic consensus that does not exist. By focusing exclusively on a single moderate warming scenario, "Cool It" fails to grapple with the real economic rationale for cutting carbon now: to buy insurance against the possibility of catastrophic outcomes.
Harvard's Weitzman puts the current concerns of many economists clearly. Based on the findings of the U.N. climate panel, he notes that with roughly 3 percent probability, "we will [live in] a terra incognita biosphere within a hundred years whose mass species extinctions, radical alterations of natural environments, and other extreme outdoor consequences of a different planet will have been triggered by a geologically-instantaneous temperature change that is significantly larger than what separates us now from past ice ages." Facing uncomfortably high probabilities for these kind of catastrophic consequences, leading economists like Weitzman are advocating a "gradualist climate-policy ramp of ever-tighter greenhouse gas reductions" that will give our kids options: options for deep cuts if needed, and options emerging from the new technologies that will be driven by steadily tightening pollution caps.
While "Cool It" misses the central issue in the debate, the book does show an interesting evolution in Lomborg's thinking. In a departure from his earlier work, and surprisingly, given his downplaying the impacts of global warming, Lomborg calls for an ambitious public investment program in clean energy technologies. I could not agree more. When my 19-year-old daughter reaches my age, her generation will have to cut global warming pollution 10-20 percent per decade. Their mission will be to rewire the entire planet with low-cost, clean energy technologies, creating tens of millions of jobs, stabilizing the climate, and laying the foundation for a prosperous and sustainable future. But if we don't invest today in fuel cells, solar arrays, and biofuel technologies, she simply won't have the affordable tools to do for her kids what she will need to.
Lomborg, however, focuses exclusively on public investment, dismissing in one sentence the sound economic argument that a cap on carbon, by raising the price of dirty fuels, will be a critical spur to private investment in clean technologies. To foster the kind of technology revolution that can stabilize global warming pollution, significant government support will be necessary, but far from sufficient.
Lomborg considers himself a friend of the world's poor. A table in his book shows all the good things that we could do with the hypothetical $180 billion he argues Kyoto would have cost. But faith, hope and charity are not zero-sum goods. A world brought together around a common agenda of stabilizing the climate will be more, not less likely, to tackle other common projects.
At the end of the day, Lomborg believes in the morality of benefit-cost analysis: No god but GDP. Funds diverted into capping global warming pollution means fewer "schools and hospitals" (as well as fewer Hummers and McMansions). For the half of the world's population still living in poverty, economic growth as conventionally measured remains an important priority. For the 2 billion of us living in relative comfort, however, slightly slower GDP growth would sacrifice little if any additional happiness. And as Lomborg acknowledges, most of the benefits of a moderately warmer climate (longer growing seasons, reduced cold days) accrue to the global North, while most of the costs (impacts on tropical agriculture, hotter summers, vulnerability to extreme weather) fall on the poor in the global South.
But give Lomborg his whole argument. Suppose, as he believes, that Kyoto-level controls will cost a cumulative $5 trillion over the next 100 years. That is about two years' worth of increase in global output. Suppose also that we ignore Lomborg's advice and in the next few years freeze global warming pollution in the rich countries. That would mean that a century hence, our descendants, living in a much richer world, would have to wait an additional two years -- until 2109 -- until a growing global economy left them as rich as they otherwise would have been in 2107.
Will they thank us? Stabilizing emissions now will open the door for deeper reductions should our kids need to make them, and send powerful signals to the marketplace about future demand for the low-carbon, low-cost technologies that will be critical to stabilize the climate by the end of the century. Continued pollution closes off those options. And unchecked, in the year 2107, over a third of the terrestrial creatures on the planet could be locked into extinction from habitat destruction due to global warming.
Noah, build that ark.
About the writer
Eban Goodstein is a professor of economics at Lewis & Clark College. He directs a national educational initiative on global warming solutions, Focus the Nation. His latest book is "Fighting for Love in the Century of Extinction: How Passion and Politics Can Change the Future."
Related Stories
Bjørn Lomborg feels a chill
Global warming doesn't faze the infamous author, who argues that polar bears are doing fine and Al Gore is way too hot under the collar. But can the "skeptical environmentalist" back up his rosy views?
Story finder (3 ways to search Salon)
Salon Directory (browse by topic)
