Michael Crichton’s new novel State of Fear is about global-warming hysteria ginned up by a self-important NGO on behalf of evil eco-terrorists … or by evil eco-terrorists on behalf of a self-important NGO. It’s not quite clear. Regardless, the message of the book is that global warming is a non-problem. A lesson for our times? Sadly, no.
In between car chases, shoot-outs, cannibalistic rites, and other assorted derring-doo-doo, the novel addresses scientific issues, but is selective (and occasionally mistaken) about the basic science involved. Some of the issues Crichton raises are real and already well-appreciated, while others are red herrings used to confuse rather than enlighten.
The fictional champion of Crichton’s climate skepticism is John Kenner, an MIT academic-turned-undercover operative who runs intellectual rings around two other characters — the actor (a rather dim-witted chap) and the lawyer (a duped innocent), neither of whom know much about science.
So, for the benefit of actors and lawyers everywhere, I will try to help out.
Early on in State of Fear, a skeptical character points out that while carbon dioxide was rising between 1940 and 1970, the globe was cooling. What, then, makes us so certain rising CO2 is behind recent warming?
Good question. Northern-hemisphere mean temperatures do appear to have fallen over that 30-year period, despite a concurrent rise in CO2, which if all else had been equal should have led to warming. But were all things equal? Actually, no.
In the real world, climate is affected both by internal variability (natural internal processes within the climate system) and forcings (external forces, either natural or human-induced, acting on the climate system). Some forcings — sulfate and nitrate aerosols, land-use changes, solar irradiance, and volcanic aerosols, for instance — can cause cooling.
Matching up what really happened with what we might have expected to happen requires taking into consideration all the forcings, as best as we can. Even then, any discrepancy might be due to internal variability (related principally to the ocean on multi-decadal time scales). Our current “best guess” is that the global mean changes in temperature, including the 1940-1970 cooling, are quite closely related to the forcings. Regional patterns of change appear to be linked more closely to internal variability, particularly during the 1930s.
No model that does not include a sharp rise in greenhouse gases (GHGs), principally CO2, is able to match up with recent warming. Thus the conclusion that GHGs are driving warming.
The book also shows, through the selective use of weather-station data, a number of single-station records with long-term cooling trends. In particular, characters visit Punta Arenas, at the tip of South America, where the station record posted on the wall shows a long-term cooling trend (though slight warming since the 1970s). “There’s your global warming,” one of Crichton’s good guys declares dismissively.
Well, not exactly. Global warming is defined by the global mean surface temperature. No one has or would claim that the whole globe is warming uniformly. Had the characters visited the nearby station of Santa Cruz Aeropuerto, the poster on the wall would have shown a positive trend. Would that have been proof of global warming? No. Only by amalgamating all available records can we have an idea what the regional, hemispheric, or global means are doing. That’s why they call it global warming.
Tall, Dark, and Hansen
Even more troubling is some misleading commentary regarding climate-science pioneer (and my boss) James Hansen’s testimony to Congress in 1988. “Dr. Hansen overestimated [global warming] by 300 percent,” says our hero Kenner.
Hansen’s testimony did indeed spread awareness of global warming, but not because he exaggerated the problem by 300 percent. In a paper published soon after that testimony, Hansen and colleagues presented three model simulations, each following a different scenario for the growth in CO2 and other trace gases and forcings. Scenario A had exponentially increasing CO2, scenario B had a more modest business-as-usual assumption, and scenario C had no further increase in CO2 after the year 2000. Both B and C assumed a large volcanic eruption in 1995.
Rightly, the authors did not assume they knew what path CO2 emissions would take, and presented a spectrum of possibilities. The scenario that turned out to be closest to the real path of forcings growth was scenario B, with the difference that Mt. Pinatubo erupted in 1991, not 1995. The temperature change for the ’90s predicted under this scenario was very close to the actual 0.11 degree-Celsius change observed.
So, given a good estimate of the forcings, the model did a reasonable job. In fact, in his congressional testimony Hansen only showed results from scenario B, and stated clearly that it was the most probable scenario.
The claim of a “300 percent” error comes from noted climate skeptic Patrick Michaels, who in testimony before Congress in 1998 deleted scenarios B and C from the chart he used in order to give the impression that the models were unreliable. Thus a significant success for climate modeling was presented as a complete failure — a willful distortion that Crichton adopts uncritically.
The well-known and exhaustively studied “urban heat island effect” — the tendency for cities to be warmer than the surrounding countryside due to the built-up surroundings and intensive energy use — is also raised several times in the book. Most recently, a study by David Parker published last year in the journal Nature found no residual effect in the surface temperature record once corrections were made for this undisputed phenomenon. Though Crichton makes much of it, there’s no there there.
At the end of the book, Crichton offers a somber author’s note. In it, he reiterates the main points of his thesis: that there are some who push claims beyond what is scientifically supported in order to drum up support (and I have some sympathy with this), and that because we don’t know everything, we actually know nothing (here, I beg to differ).
He gives us his back-of-a-napkin estimate for the global warming that will occur over the next century — an increase of approximately 0.8 degrees Celsius — and claims that his guess is as good as any model’s. He suggests that most of the warming will be due to land-use changes — extremely unlikely, as globally speaking, land-use change has a cooling effect. As his faulty assumptions painfully demonstrate, simulations based on physics are better than just guessing.
Finally, in an appendix, Crichton uses a rather curious train of logic to compare global warming to the 19th century eugenics movement. Eugenics, he notes, was studied in prestigious universities and supported by charitable foundations. Today, global warming is studied in prestigious universities and supported by charitable foundations. Aha!
Presumably Crichton doesn’t actually believe that foundation-supported academic research is ipso facto misguided, even evil, but that is certainly the impression left by this peculiar linkage.
In summary, I am disappointed, not least because while researching his book, Crichton visited our lab at the NASA Goddard Institute and discussed some of these issues with me and a few of my colleagues. I suppose we didn’t do a very good job of explaining matters. Judging from his bibliography, the rather dry prose of reports by the Intergovernmental Panel on Climate Change did not stir his senses quite like some of the racier contrarian texts. Unsurprisingly, perhaps, Crichton picked fiction over fact.
Scientifically curious readers can find a more detailed version of this review on RealClimate.org.