TCS Daily


Storm Front

By Paul J. Georgia - March 28, 2003 12:00 AM

Does the greenhouse effect really work like a greenhouse? Does the average global temperature provide any meaningful climatic information? Is there even a theory of climate? These are some of the questions asked and answered in a new book, Taken by Storm: The Troubled Science, Policy and Politics of Global Warming, written by Christopher Essex, a professor in the Department of Applied Mathematics at the University of Western Ontario, and Ross McKitrick, an associate professor in the Department of Economics at the University of Guelph.

As the title notes, the book addresses both science and politics. As we shall see, the science underlying global warming alarmism is flimsier than most people, even many scientists, suspect. How we have reached a point where the world is on the verge of putting into force a treaty, the Kyoto Protocol, that would stifle economic growth in the developed countries and preclude it in the third world, in the absence of scientific evidence, demands an answer. The answer lies in the perverse incentives that arise from the subjugation of science to politics.

No Physical Meaning

Essex, who studies the underlying mathematics, physics and computation of complex dynamic processes, raises some very fundamental scientific issues with regard to global warming. Take, for instance, the "average global temperature," which is the primary statistic offered as evidence of global warming. The problem with this statistic is that it has no physical meaning. Temperature is not a thermodynamic variable that lends itself to statistical analysis, nor does it measure a physical quantity.

Thermodynamic variables are of two types, says Essex, extensive and intensive. Extensive variables, like energy or mass, occur in amounts. Intensive variables, such as temperature, refer to conditions of a system. A cup of hot coffee, for example, contains an amount of energy and has a temperature. If you add an equal amount of coffee with the same amount of energy and the same temperature to the cup, the amount of energy doubles, but not the temperature. The temperature remains the same. Thus, while you can add up the energy from two separate systems and get total energy, it is physically meaningless to add up the two systems' temperatures. And dividing that number by two doesn't give you the average temperature either. Such an exercise results in a statistic that has no physical meaning. Yet that is exactly what occurs when the average global temperature is computed.

Moreover, temperature and energy aren't the same thing. The internal energy of a system can change without changing the temperature and the temperature can change while the internal energy of the system remains the same. In fact, this occurs all the time in the climate because the two variables are fundamentally different classes of thermodynamic variables and there is no physical law that requires that they move together. The next time somebody informs you that the planet's "average temperature" has increased, you can rest assured that they have told you exactly nothing.

Flawed Metaphor

Taken by Storm also takes on the greenhouse metaphor. The so-called greenhouse effect does not work like a greenhouse. Incoming solar radiation adds energy to the Earth's climate. To restore radiative balance, the energy must be transported back to space in roughly the same amounts in which it arrived. The energy is transported via two processes - infrared radiation (heat transfer) and fluid dynamics (turbulence). "When you add up the net amount of energy flow away from the surface by pure (infrared) radiation, it turns out to be roughly the same as that carried away by wind, air movements and evaporation," says Essex.

A greenhouse, however, works by preventing fluid motions, such as wind, by enclosing an area with plastic or glass. To restore balance, infrared radiation must increase, thereby causing the temperature to rise. Predicting the resulting temperature increase is a relatively straightforward process. If you think of the climate system as a gigantic greenhouse, it's easy to assume that we can calculate how much the temperature will rise from an increase in greenhouse gases. But the greenhouse picture ignores the fluid dynamics half of the story.

The "greenhouse effect" works differently. Greenhouse gases slow down outgoing infrared radiation, which causes changes in turbulence. But it cannot be predicted what will happen because the equations which govern turbulence cannot be solved! "In the case of turbulence," writes Essex, "we can't even forecast from first principles the average flow in a simple pipe." The climate system is a vastly more complex turbulent system than a pipe. It is impossible to determine from first principles whether an increase in greenhouse gases will lead to warming, cooling or no change.

This is why Essex argues that there is no theory of climate. We do have equations governing turbulence, but not on the enormous scale of climate. "There is no one living on climate scales to observe structures, do experiments or establish physically meaningful structure for us," he says. "We are little better than bacteria in a test tube trying to deduce from first principles what the laboratory ought to look like."

Model Problems

Essex also takes on the practice of parameterization in climate modeling. Parameters are simple numbers that stand in place of tremendously complex climatic processes that we really don't understand. Parameters used in climate models are not derived from theory, which doesn't exist at the level of climate, or from observation, says Essex. "Everything [in the climate models] from convection to clouds, rain and the general cycle of water into and out of the system - everything that has to do with moving energy from the surface of the Earth to space - is made up." This is very important because a slight change in a model parameter can lead to totally different projections.

Climate models, for example, assume that temperature decreases by 6.5 degrees Celsius per kilometer of altitude. At a certain altitude the temperature is such that the amount of radiation entering the climate system equals the amount leaving it. This altitude is known as the "characteristic emission level" (CEL). A doubling of atmospheric carbon dioxide concentrations causes the CEL to move out about 300 meters. To figure out how this affects the surface, one can simply calculate the temperatures from the CEL by adding 6.5 degrees C per kilometer all the way down to the surface, which shows a warming of about 2 degrees C at the surface.

The problem with this exercise is that there is no single rate at which temperature changes with altitude. It varies from 4 to 10 degrees C. Nor is there a single level for the CEL, but an infinite number of levels. The 6.5 degree C figure is just a parameter based on a simplistic model of the atmosphere. If you change that parameter to 6.2 degrees C the projected warming disappears. At 6.1 degrees C the model projects cooling. "The models show surface warming from adding carbon dioxide to the atmosphere because of their programming," says Essex. "They could yield surface cooling with different programming, without violating any physical law. All that is required is to allow things to change in the model that do in fact change in the atmosphere."

'Official Science'

Surely scientists are aware of these issues (and many others discussed in the book). If so, then how have we come to a place where the media and politicians repeatedly state that there is a scientific consensus that the planet is warming up, it is caused by man, and the effects will be catastrophic? Dr. McKitrick offers a very convincing explanation. He discusses several relevant groups, but we'll focus on politicians and what McKitrick calls "Official Science."

Politicians need big issues around which they can form winning coalitions. Global warming is great because it is a complex and baffling scientific issue that can be reduced to a simple matter of "warming" without the public being the wiser, and it allows politicians the prospect of becoming global statesman and proposing heroic planet-saving initiatives. However, such initiatives can be very costly, so politicians need a high degree of scientific support.

This is where Official Science comes in. Official Science is not made up of working research scientists, but rather staffs of scientific bureaucracies, national and international science panels, and so on. These members of Official Science aren't appointed by scientists to speak on their behalf, but are middlemen who control the distribution of research money and define "scientific truth" for the public. They have the job of striking "a mad compromise between the realities of politics and the realities of nature," writes McKitrick. "So while scientists are skeptical of their own work and that of others, Official Science speaks with the simple confidence that good politics requires and journalism demands, but which science abhors."

The United Nations' Intergovernmental Panel on Climate Change is the premier representative of Official Science. Its governing principles state that it shall concentrate its activities on "actions in support of the UN Framework Convention on Climate Change process." This is Official Science in the service of politics. The IPCC has repeatedly proclaimed that it represents "the consensus" on global warming science. Former IPCC Chairman Robert Watson stated in 2001 that the IPCC's summary report added "impetus for governments of the world to find ways to live up to their commitments ... to reduce emissions of greenhouse gases."

So what can be done to fix this problem of science shilling for politics? How do we "make sure science is free to investigate [climate change], without having to prove constantly that this or that is relevant to policy issues?" Essex and McKitrick offer a modest proposal. Instead of one IPCC report, there should be two reports. One report would be written by global warming alarmists and the other by global warming skeptics, each drawn from the ranks of scientists. Each group would make the best case for its position and provide a rebuttal of the other's position. There would be no summaries written by Official Science middlemen to "interpret" the meaning of the two reports. If politicians wanted to know the state of the science, they would have to read the reports themselves and come to their own conclusions.

Will it happen? Not likely. Official Science isn't about to relinquish its monopoly on defining scientific truth, nor the perquisites (good pay, travel to exotic locations) of its position.

Paul Georgia is an environmental policy analyst with the Competitive Enterprise Institute in Washington, D.C.
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