TCS Daily

Storm Front

By Sallie Baliunas - July 15, 2003 12:00 AM

"We wrote this book," Professors Christopher Essex and Ross McKitrick state, "because we got tired of opening the newspaper or turning on the TV news and seeing a river of idiotic, alarmist nonsense rushing out at the public" on catastrophic human-made global warming.

In their lively and lucid book Taken by Storm, The Troubled Science, Policy and Politics of Global Warmingthe authors defend science as the only way to measure and address the risk of human effects on global climate. Essex is an applied mathematician who studies complex systems like the climate, and McKitrick is an economist who works on environmental policy.

Central to public angst about climate is scientific misunderstanding of it, so Essex and McKitrick explain some of the scientific concepts of climate, including its uncertain, unknown, and unknowable aspects.

One errant public metaphor discussed in Taken by Storm describes the earth's climate as a greenhouse. The air's content of carbon dioxide, methane and other infrared-absorbing gases emitted by human activities has increased, especially in the last 50 years. The increase in the amount of gases in the air acts to keep a fraction of energy in the climate system that would have otherwise escaped to space. In the simplified scientific starting point, that added energy should result in some global warming.

But the climate system does not act like a greenhouse, which mechanically blocks the flow of air, and thus keeps the enclosed air warm.

Climate is not that simple. It is a rich, nonlinear system where small changes in one of its many elements or variables may cascade to greatly affect others. Compound that with millions of variables, many interacting significantly with each other as one, two, then more, respond. Intricate computer simulations try to incorporate what is known in order to get to the important point: how the climate responds to the relatively small amount of energy added by the air's increased carbon dioxide content. But the climate system is not yet sufficiently known, and therefore, the simulations include uncertainties and their consequences as they cascade through the equations.

For example, convection transports enormous amounts of energy and moisture in the climate system. Large-scale motion of energy from the equator toward the polar regions, cumulonimbus clouds and thunderstorms all owe their existence to convection. But convection -- both as a physical process and as it applies to climate -- remains poorly understood. As Essex and McKitrick point out, making adjustments within uncertainties of parameters related to convection or clouds in climate simulations can turn a warming trend to a cooling trend.

The simulations and their results do not sufficiently explain well-measured properties of current and past climate to yield reliable results. That is why the U.N. Intergovernmental Panel on Climate Change, which produces a series of assessments that distill current research on climate, carefully labeled in its last report (2001) results of climate simulations as "projections" based on "illustrative scenarios."

Nonetheless, the public idea has grown to fossil fuels, greenhouses and a scorched earth, backed by something called a consensus.

To illustrate the impact of that erroneous concept, Essex and McKitrick juxtapose the scientific uncertainty of a climate process like convection against the socio-political "convection of certainty" in public debate on human-caused global warming.

Chapter 2 of Taken by Storm notes that the journal Nature (July 12, 2001) editorialized "[Industrial lobbying groups in the U.S.] have championed specious scientific findings and worked to establish a bogus scientific debate..." whose purpose is to "confuse and delude the U.S. public on global warming."

Essex and McKitrick observe that such statements constitute "a brazen flouting of the institutional impartiality essential to the health of normal science."

Taken by Storm continues its look at the process of consensus. Sir John Houghton, who served as co-chair of one of the early U.N. assessment reports, later remarked on the question of delivering uncertain future climate projections in the U.N. report: "...[S]ome felt that the uncertainties were such that scientists should refrain from making any estimates or predictions for the future...Weather forecasters have a similar, although much more short-term responsibility. Even though they may feel uncertain about tomorrow's weather, they cannot refuse to make a forecast... It has often been commented that without the clear message which came from the world's scientists, orchestrated by the IPCC, the world's leaders would never have agreed to sign the [Rio] Climate Convention."

Neatly summarizing that admission of socio-political pressure brought on science, Essex and McKitrick write, "It gathers in normal science in all its tumultuous reality: open debate, dissension and a refusal to make definitive claims where none are to be had... Debate and dissent are extruded into a 'clear message which came from the world's scientists, orchestrated by'" the IPCC.

Essex and McKitrick recommend that society protect full and open scientific debate on climate. That is the only way to improve well-appreciated difficulties of convection in the climate calculations. "We have to learn," they say, "to have more respect for the technicalities."

Relying on politically forced consensus -- which is not a process of normative science -- undermines the free inquiry vital to science. Without society's protection of science from political pressure, the scientific facts on a major environmental concern such as the impact on the ecosystem of adding carbon dioxide and methane to the air will be brushed aside. Swept in instead will be superstition.

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