To the Editor:
In his article “Too Darn Hot?” [June], Kevin A. Shapiro, a researcher in neuroscience, assures us that the majority opinion among climatologists with regard to the greenhouse effect is, at the least, overly alarmist. May we assume that, should an issue in neuroscience arise with major public-policy consequences, COMMENTARY will publish a climatologist explaining to us why the majority of neuroscientists are wrong?
Readers with access to an Internet search engine might type in the words “polar ice cap” and “melting” and see what comes up. They will find numerous references to thinning polar ice, decreasing salinity (a consequence of increased rates of melting), and softening permafrost. The Washington Post recently carried a front-page story to the effect that in the last three decades, Peru has lost almost one-fourth of its former 1,225 square miles of Andean glaciers due to atmospheric warming.
I understand that from the perspective of political conservatives, it is nice to think the greenhouse effect can be disregarded; doing so obviates the need for controls, regulations, and taxes of various sorts. But adopting a scientific stance because of political imperatives is no way to get at the truth.
John M. Levy
Blacksburg, Virginia
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To the Editor:
Kevin Shapiro makes a small but crucial technical error when he writes:
Increases in the industrial emission of gases like carbon dioxide (CO2), it is said, have caused the atmosphere to absorb infrared radiation that would otherwise be reflected back into outer space. The resulting “greenhouse effect” lifts the average temperature of the earth’s surface.
The word “reflected” means the same radiation that came in goes back out. This is not what is happening in the greenhouse effect.
The sun bathes the earth in radiation. A fraction (37 percent) of this radiation is reflected straight back into space. But most of it (the other 63 percent) is absorbed by the earth and then reradiated, from both its dayside and nightside, back into space. In this way, apart from diurnal and seasonal variations, the earth’s surface maintains a roughly constant temperature. But because the earth is much, much cooler than the sun, the radiation it sends back into space is at infrared wavelengths, while the radiation it receives from the sun is at the much shorter wavelengths of visible light.
A greenhouse gas is one, like carbon dioxide (CO2), that is composed of three or more atoms and is transparent to visible light but opaque to infrared radiation. By contrast, gases whose molecules are composed of two atoms, such as oxygen (O2) and nitrogen (N2), are transparent at both visible and infrared wavelengths and so are not greenhouse gases. We now come to the big question: which gas is the major greenhouse gas? It is not carbon dioxide. The major greenhouse gas is water vapor (H2O).
Water vapor, whose presence is determined by natural processes—the balance between evaporation from the oceans and precipitation—contributes 97 to 99 percent of the total thermal trapping caused by the earth’s atmosphere. Carbon dioxide contributes the other 1 to 3 percent. Thus, although the concentration of carbon dioxide over the last 100 years has increased by about 25 percent, the fact that carbon dioxide makes only a minor contribution to the total means that there has been nothing like a corresponding increase in the amount of thermal trapping.
In short, the threat of catastrophic man-made global warming is a chimera.
Jocelyn Tomkin
University of Texas
Austin, Texas
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To the Editor:
Howls of protest from predictable quarters greeted President Bush’s decision to walk away from the Kyoto Protocol. Yet the uproar cannot obscure how weak the case of the treaty’s supporters really is.
As Kevin Shapiro correctly points out, the Kyoto Protocol stood no chance of ever being ratified by the U.S. Senate. Nor has a single member of the European Union ratified the treaty, even though the EU as a whole emits more greenhouse gases than the U.S. European governments may say they want to “shame” Washington into returning to the Kyoto fold, but the treaty was already dead, and Bush wisely decided to bury it.
In the U.S., Bush’s decision met with expressions of outrage by environmentalists, political commentators, and politicians like Senators Joseph Lieberman and John Kerry. The move coincided with the administration’s withdrawing of a last-minute Clinton proposal to tighten the standard for arsenic in drinking water, which only increased the environmentalists’ ire. Yet in the wake of both decisions, the President’s approval ratings stood at over 60 percent, an astonishing level given his narrow margin of victory in last November’s disputed election. What this tells us is that the environmentalists’ bark is far worse than the political staying power of their bite.
Bonner R. Cohen
Lexington Institute
Arlington, Virginia
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Kevin A. Shapiro writes:
Contrary to John M. Levy’s suggestion, science is neither the secret preserve of a cult of initiates nor a debating society that arrives at truth by consensus; it is not impervious to error, overconfidence, or ideological bias. The fact that most climatologists believe human activity is leading to climate change may mean nothing more than that most climatologists are wrong.
Until very recently a majority of medical researchers believed that peptic ulcers were precipitated by stress and stomach acidity, best treated with milk and relaxation. In reality, most ulcers are caused by bacterial infections, which can be eliminated easily with antibiotics. Much less is known about the earth’s climate than about peptic ulcers, and the cost of the proposed remedy for global warming vastly exceeds that of a glass of milk.
Most policymakers—even those who ostensibly support the Kyoto process—seem to appreciate this imbalance, and Bonner R. Cohen correctly notes a discrepancy between the verdurous rhetoric of left-wing European and American politicians and the measures they are actually willing to take to curb greenhouse-gas emissions. For example, the deal recently reached in Bonn to “save” Kyoto (and “shame” the United States) may not result in any emissions reductions at all, for reasons I elucidated in my article, even if it is eventually ratified by European parliaments.
Of course, this is not necessarily a bad thing. As Jocelyn Tomkin points out, no amount of rhetoric will invalidate the conclusion that, at present, there is simply no sound scientific reason to believe that increased carbon-dioxide emissions are responsible for global warming. Uncertainties about the effects of variables like cloud cover and water vapor dwarf the potential impact of human activity, and there is too much “noise” in the data to make long-term predictions about the climate with any accuracy.
Nevertheless, Mr. Levy’s letter is instructive, and perhaps ironic, in that it reveals the extent to which proponents of emissions reduction and regulation are willing to treat the facts selectively in promoting their cause. It is true that a casual search of the Internet (or, better yet, a search of the scientific literature) will turn up evidence that glaciers everywhere seem to be retreating, and that the amount of summer sea ice in the Arctic has recently been decreasing. Such data are seized upon by environmental doomsayers, and immediately trumpeted by the major news outlets as proof of global warming.
But the same search will also unearth findings that the average Arctic winter ice cap is stable, that the extent of sea ice has not changed at all in the Antarctic, and that local changes in glaciation and snow cover are not necessarily consistent with changes in atmospheric temperature. Indeed, many geologists who study ice caps and glaciers believe that we are still witnessing the aftermath of climate changes that occurred hundreds or even thousands of years ago. Yet this is reported rarely, if at all.
Why? I understand that from the perspective of the Left, it is nice to think that the complexities of the evidence can be disregarded; doing so makes it considerably easier to advocate controls, regulations, and taxes of various sorts. But, as Mr. Levy writes, this is no way to get at the truth.
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