TCS Daily


Global Warming Trends

By Paul J. Georgia - February 18, 2003 12:00 AM

Global warming has to be one of the strangest policy debates the country has ever seen. Sure there are always two or more competing sides, pandering, demagoguery and outright dishonesty in every policy debate. But in the case of global warming the contrasts are so stark and the political statements so divorced from reality, that informed persons are left shaking their heads in disbelief.

On the one hand, you have politicians stating categorically: "The science is settled!" On the other hand, one can dig up a half dozen National Academy of Sciences reports from the last five years that argue that not only is the science not settled, but that scientists are operating in almost complete ignorance on many of the most basic and key assumptions behind the theory.

An NAS report, published in 1998, states: "Without a clear understanding of how climate has changed naturally in the past, and the mechanisms involved, our ability to interpret any future change will be significantly confounded and our ability to predict future change severely curtailed." Another NAS report published that same year states: "Large gaps in our knowledge of interannual and decade-to-century natural variability hinder our ability to provide credible predictive skill or to distinguish the role of human activities from natural variability." In 2001, the NAS admitted that " ... the observing system available today is a composite of observations that neither provide the information nor the continuity in the data needed to support measurements of climate variables."

Far from being settled, the science is still in its infancy. "Climate research is only at the beginning of its learning curve, with dramatic findings appearing at an impressive rate. In this area, even the most fundamental scientific issues are evolving rapidly," says the NAS.

Dr. David Wojick, who has a Ph.D. in mathematical logic and philosophy of science and author of a recent review of NAS climate reports, argues that there has been a quiet revolution in climate science. "It seems that we have discovered or confirmed a number of natural mechanisms of climate change, at least 10 in fact. These mechanisms provide alternative, competing explanations for global warming, alternative to, and competing with, the theory of human-induced warming. Also alternative to, and competing with, each other.

"Each of these mechanisms can in theory explain all of the changes in 20th Century climate. Human greenhouse gas emissions are therefore just one of many alternative hypotheses. In addition, the evidence for warming due to greenhouse gas emissions is no greater than for any of the other mechanisms."

As a result of this revolution, increases in our understanding about climate change have been paralleled by increases in the uncertainty about man's contribution, if indeed there is one.

At a briefing for congressional staffers and media sponsored by the Cooler Heads Coalition on Feb. 7, Jesse Ausubel, a researcher at The Rockefeller University, laid out a framework for thinking about global warming issues. There are several points at which the issue is being debated. There are the issues of energy use, emissions and concentrations; climate sensitivity, or how much the climate may warm due to increases in greenhouse gas concentrations; the potential impacts on ecosystems and people, and so on.

Ausubel argued that many of these issues are essentially unknowable. Climate sensitivity, for example, has been estimated at different extremes. The aggregate results from peer-reviewed scientific studies show a normal distribution of climate sensitivities. Some suggest that a doubling atmospheric carbon dioxide concentration will warm the climate by about 4.5 degrees Celsius. Others show low climate sensitivity, which would lead to a warming of 1.5 degrees C. Still others fall somewhere in the middle. As Ausubel stated, "The pile of papers keeps getting larger, but the shape of the pile never changes."

The real debate, according to Ausubel, lies in the trends in energy use. This is one variable that is known, and as Ausubel has discovered, the world has experienced a sustained long-running reduction in carbon intensity in its energy use. Wood, still a major source of fuel in less developed countries, has a hydrogen-to-carbon ratio of 1 to 10. Coal's H:C ratio is 1 to 2, oil 2 to 1, and methane or natural gas about 4 to 1.

The world has been steadily decarbonizing for the last 150 years, from wood to coal to oil, and now to methane. Ausubel argues, somewhat controversially, that total decarbonization is in our future and that the economy will run on hydrogen, powered by nuclear power. That may well be the case.

One of the major implications of decarbonization is that energy policy may be irrelevant. As Ausubel has noted elsewhere, neither Queen Victoria nor Abraham Lincoln decreed a policy of decarbonization. Yet, the system pursued it." Decarbonization and our path to the hydrogen economy will happen regardless of government decrees or federal research money.

Ausubel also takes to task the U.N. Intergovernmental Panel on Climate Change for its assumptions on energy use. When Ausubel extrapolated decarbonization trends out to the year 2100 and compared it to the IPCC's 1990 "business as usual" (BAU) scenario he found that they bore little resemblance to one another. The IPCC's BAU scenario was a flat line, which assumes technical stagnation, or what Ausubel dubs the Brezhnev Scenario. But properly understood, BAU is a technologically dynamic and progressive scenario that will eliminate CO2 by 2100. The IPCC's 2001 Third Assessment Report uses 40 scenarios that show decarbonization and carbonization going in all different directions with no probabilities attached.

Next time you hear politicians drone on and on about scientific opinion on global warming and the need to expend hundreds of billions of the taxpayer's hard earned money on new energy technologies to stop it, keep in mind two things: the science is becoming less settled each day, and the energy system may well take us where we want to go long before the politicians have figured out what is going on.
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