New Book Misrepresents Climate Change Science

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Ken Caldeira, the primary climate scientist interviewed in “SuperFreakonomics,” has said the book inaccurately portrays his views.

The new book SuperFreakonomics by Steven D. Levitt and Stephen J. Dubner is slated to be released on Oct. 20, 2009. Experts at the Union of Concerned Scientists found that the fifth chapter of the book, “Global Cooling,” repeats a large number of easily discredited arguments regarding climate science, energy production and geoengineering.

The authors appear to have taken a purposefully contrarian position on climate change science and economics. While such a position may help draw attention to their book, their reliance on faulty arguments and distorted statistics does a disservice to their readers.

In 20 short pages, the authors:

  • Repeat tired global cooling myths
  • Unfairly trash climate models
  • Highlight irrelevant statistics about carbon dioxide without context
  • Extol the virtues of excess carbon dioxide while ignoring the downsides
  • Ignore a major source of sea level rise
  • Cherry-pick short-term climate fluctuations while missing the bigger picture
  • Use faulty statistics to trash renewable energy
  • Advocate rolling the dice on unproven technology
  • Use a silly analogy to attack plans to reduce emissions

Repeat tired global cooling myths

First, the chapter rehashes 1970s global cooling myths (pages 165 and 166). In fact, the 1970s “cooling scare” is largely an invention of the opponents of addressing climate change. Only a few news organizations reported on a handful of scientific papers regarding cooling in the 1970s. What was going on? Scientists noted that sulfur-dioxide production and other particulates that reflect sunlight were on the rise, outstripping the effect of heat-trapping gases such as carbon dioxide and methane. Over time, industry reduced emissions of these cooling pollutants, which also cause acid rain. Meanwhile, fossil fuel emissions and deforestation have exploded, leading to an overabundance of warming gases in our atmosphere. The scientific research on global warming is orders of magnitude larger and more robust than the science underpinning a handful of cooling articles in the 1970s.

Unfairly trash climate models

The authors claim climate models have a very wide range of future temperature projections (page 168). This is true, but it misses the point. Climate models have a wide range because scientists don’t know how many more heat-trapping emissions human activity will put into the atmosphere. Models project that a decrease in production of heat-trapping emissions would lead to less warming — around 2 degrees Fahrenheit by the end of the century — while continued high emissions would lead to greater warming — closer to 10 degrees Fahrenheit. The authors gloss over the fact that reducing heat-trapping gases will lower warming. This simple fact undercuts most of the authors’ discussion regarding whether reducing emissions is an effective tool for reducing global warming. According to climate models, it is the method for doing so.

The authors emphasize the fact that climate models don’t account for relatively small-scale phenomena such as hurricanes (pages 181 and 182). Climate models by their nature focus on the macro-, not the micro-scale. The authors’ complaint is akin to criticizing a desk-stand globe because it doesn’t display the street where they live. Climate models all agree that, on the large scale, land and ocean areas worldwide will experience warming as heat-trapping emissions continue to rise.

Highlight irrelevant statistics about carbon dioxide without context

The authors note that carbon dioxide concentrations in the atmosphere were higher 80 million years ago (pages 181 and 182). This is true, but largely irrelevant to the question of whether we should do anything to address global warming today. Carbon dioxide and temperature fluctuate naturally on well-understood cycles that take place over tens of thousands of years. Current warming, brought about by human-induced emissions, has been happening over a condensed period of time. To flourish, our civilization has relied on the relatively stable climate of the past few thousand years. Rapid change to that climate is a serious threat.

Extol the virtues of excess carbon dioxide while ignoring the downsides

The authors point out that many plants benefit from higher carbon dioxide concentrations (page 184). While this is true, they ignore how plants suffer when the planet warms. A warmer world would disrupt agricultural production, shift the areas suitable for many tree species, and increase the range of pests and pathogens. And while beneficial plants may grow faster with increased carbon dioxide, so do weeds, allergens and invasive species. Overall, a higher rate of growth for some plants is a minor benefit compared with the major disruptions for human society that scientists project under an extreme warming scenario.

Ignore a major source of sea level rise

The authors maintain that sea levels can rise only 1.5 feet by 2100 (page 186). How did they arrive at that statistic? It seems they only considered sea level rise caused by a warming (and expanding) ocean, but failed to include additional sea level rise from melting ice sheets.

Over the last few years, scientists have gained greater understanding of how land-based glacial ice responds to warming and how much it may contribute to sea level rise. A new study using the latest climate science suggests sea levels may rise 2.6 to 6.6 feet by the end of this century depending on our emissions over the coming century. In addition, unchecked warming may at some time in the future cause the Greenland and West Antarctic ice sheets to melt completely, leading to catastrophic sea level rise.

Cherry-pick short-term climate fluctuations while missing the bigger picture

The authors briefly repeat the false claim that global temperatures have decreased over the last decade (page 186). This is an indefensible way of looking at the Earth’s temperature record. Warming is a long-term trend and temperatures continue to increase over time, though they do fluctuate year-to-year. Counting only a few years in the global temperature record is akin to trying to determine who is winning a baseball game by only counting runs scored in the seventh and eighth innings. It ignores the broader, longer-term picture. In reality, the eight warmest years on record for the globe have all occurred since 1998, and the 14 warmest years in the record have all occurred since 1990. Global mean temperatures every year this century (to the end of 2007) were all above the average of the 20th century.

Use faulty statistics to trash renewable energy

The authors criticize renewable electricity sources, notably solar power (page 187). Energy expert Joe Romm does an excellent job debunking their claims on his blog.

Advocate rolling the dice on unproven technology

The authors discuss the idea of using geoengineering to address global warming (beginning of page 193) as if it is a panacea to the global warming problem. But according to climate scientists, such technologies are unproven and the possibility they might work is no excuse for failing to curb emissions now. While geoengineering deserves research, the authors’ implication that it could be a substitute for reducing heat-trapping emissions is unfortunate. It is also worth nothing that in addition to warming the climate, carbon dioxide is also acidifying the oceans, making it less able to support marine life. Geoengineering the climate would not stop that.

Use a silly analogy to attack plans to reduce emissions

The chapter concludes with a story about doctors failing to wash their hands. The authors say this example shows how hard it is to change human behavior. This argument is a red herring. Energy efficiency, renewable electricity production, and cars that maintain performance with better fuel efficiency are all examples of technologies that reduce emissions without forcing people to change their behavior. While individual choices are incredibly important when it comes to addressing climate change, the authors’ implication that it is the only way the problem can be addressed is fundamentally wrong.

The Union of Concerned Scientists is the leading science-based nonprofit organization working for a healthy environment and a safer world. Founded in 1969, UCS is headquartered in Cambridge, Mass., and has offices in Berkeley, Calif., Chicago and Washington, D.C.