Challenge doomsayers to 'show me the science'
December 3, 1997
By David Riggs

Most people today regard "global warming" as both real and dangerous. Indeed, with 160 nations convening in Kyoto, Japan, this week for the global warming summit, one is induced to believe that this is a major crisis facing mankind.

Proponents of global warming theory speak of the scientific community in supposed agreement and cite a quote from a report by the Intergovernmental Panel on Climate Change (IPCC). They further exclaim a variety of dire consequences to result from "heattrapping greenhouse gases," such as upsurges in hurricane activity and intensity, famine and rampant tropical diseases.

The scientific evidence, however, does not support catastrophic warming scenarios. To provide some perspective, here are some facts:

• Greenhouse gases comprise only about 1 percent of our atmosphere, most of which is nitrogen and oxygen. Of that 1 percent, the most abundant greenhouse gas is water vapor, which accounts for about 98 percent of all greenhouse gases in the atmosphere.
• The climatological predictive models that serve as a basis for catastrophe scenarios fail to accurately simulate climate responses to changes h1 greenhouse gases.
• A leading weather firm, Accu-Weather, shows an increased frequency and intensity of hurricanes is not supported by theory or empirical evidence.
• Plants-a basis of all existence-flourish with increases in carbon dioxide.
• The spread of diseases is much more dependent on human behavior arLd infrastructure, such as the chlorinating of water, than it is on climate.

Richard S. Lindzen, the Alfred P. Sloan professor of meteorology at the Massachusetts Institute of Technology, states that "as a scientist, I can find no substantive basis for the warming scenarios being popularly described." Prof Lindzen is not alone in his dissent from the so-called "scientific consensus." Some 100 independent scientists signed the "Leipzig Declaration" that expresses their dissent:

"It has become increasingly clear that -- contrary to conventional wisdom -- there does not exist today a general scientific consensus about the importance of greenhouse warming from rising levels of carbon dioxide."

In addition to this "consensus," global warming advocates frequently cite a quote from the 1996 IPCC Science Report, "the balance of evidence suggests that there is a discernible human influence on global climate." Notice that this vague statement is merely a suggestion, not a conclusion. The caveat that precedes the statement is almost always left out: "Our ability to quantify the human influence on global climate is currently limited because . . . there are uncertainties in key factors."

The best available evidence to determine the human influence on global climate change is to examine actual temperature measurements. Land-based temperature measurements show about a 1 degree Fahrenheit increase in average global temperature over the last 100 years. Most of the temperature increase occurred prior to ! 940, while most of the increase in greenhouse gas emissions occurred after 1940. Based on the analysis of these data, most scientists conclude -- including Prof. Bert Bolin, chairman of the IPCC -- that this temperature increase was natural in origin, resulting from the Earth recovering from a "little ice age."

Moreover, the land-based temperature measurements are subject to the "heat island" effect from population-dense areas and may exaggerate actual temperature change. Temperature estimates from satellite data are not subject to the heat-island effect and do not support the global warming theory. In fact, the satellite data show a slight cooling trend.

Looking again to the Leipzig Declaration, it urges caution in moving forward with greenhouse gas emission reductions:

"Most scientists now accept the fact that actual observations from earth satellites show no climate warming whatsoever . . . Based on the evidence available to us, we cannot subscribe to the so-called 'scientific consensus' that envisages climate catastrophes and advocates hasty actions."

In the movie "Jerry Maguire," one of the characters refuses to sign a player-agent contract unless Jerry can "show me the money." With all the various "agents" gearing up to sign a big contract in Kyoto, citizens should insist, "Show me the science."

-- David W. Riggs, of St. Paul, is a senior fellow for economic and environmental studies at the Center of the American Experiment.