Frisco_Slug_Esq
On Strike!
- Joined
- May 4, 2009
- Posts
- 45,618
Most of the literate world today regards "global warming'' as both real and dangerous. Indeed, the diplomatic activity concerning warming might lead one to believe that it is the major crisis confronting mankind. The June 1992 Earth Summit in Rio de Janeiro, Brazil, focused on international agreements to deal with that threat, and the heads of state from dozens of countries attended. I must state at the outset, that, as a scientist, I can find no substantive basis for the warming scenarios being popularly described. Moreover, according to many studies I have read by economists, agronomists, and hydrologists, there would be little difficulty adapting to such warming if it were to occur. Such was also the conclusion of the recent National Research Council's report on adapting to global change. Many aspects of the catastrophic scenario have already been largely discounted by the scientific community. For example, fears of massive sea-level increases accompanied many of the early discussions of global warming, but those estimates have been steadily reduced by orders of magnitude, and now it is widely agreed that even the potential contribution of warming to sea-level rise would be swamped by other more important factors.
To show why I assert that there is no substantive basis for predictions of sizeable global warming due to observed increases in minor greenhouse gases such as carbon dioxide, methane, and chlorofluorocarbons, I shall briefly review the science associated with those predictions.
Summary of Scientific Issues
Before even considering "greenhouse theory,'' it may be helpful to begin with the issue that is almost always taken as a given--that carbon dioxide will inevitably increase to values double and even quadruple present values. Evidence from the analysis of ice cores and after 1958 from direct atmospheric sampling shows that the amount of carbon dioxide in the air has been increasing since 1800. Before 1800 the density was about 275 parts per million by volume. Today it is about 355 parts per million by volume. The increase is generally believed to be due to the combination of increased burning of fossil fuels and before 1905 to deforestation. The total source is estimated to have been increasing exponentially at least until 1973. From 1973 until 1990 the rate of increase has been much slower, however. About half the production of carbon dioxide has appeared in the atmosphere.
Predicting what will happen to carbon dioxide over the next century is a rather uncertain matter. By assuming a shift toward the increased use of coal, rapid advances in the third world's standard of living, large population increases, and a reduction in nuclear and other nonfossil fuels, one can generate an emissions scenario that will lead to a doubling of carbon dioxide by 2030--if one uses a particular model for the chemical response to carbon dioxide emissions. The Intergovernmental Panel on Climate Change Working Group I's model referred to that as the "business as usual'' scenario. As it turns out, the chemical model used was inconsistent with the past century's record; it would have predicted that we would already have about 400 parts per million by volume. An improved model developed at the Max Planck Institute in Hamburg shows that even the "business as usual'' scenario does not double carbon dioxide by the year 2100. It seems unlikely moreover that the indefinite future of energy belongs to coal. I also find it difficult to believe that technology will not lead to improved nuclear reactors within fifty years.
Nevertheless, we have already seen a significant increase in carbon dioxide that has been accompanied by increases in other minor greenhouse gases such as methane and chlorofluorocarbons. Indeed, in terms of greenhouse potential, we have had the equivalent of a 50 percent increase in carbon dioxide over the past century. The effects of those increases are certainly worth studying--quite independent of any uncertain future scenarios.
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Modelling and Societal Instability
So far I have emphasized the political elements in the current climate hysteria. There can be no question, however, that scientists are abetting this situation. Concerns about funding have already been mentioned. There is, however, another perhaps more important element to the scientific support. The existence of modern computing power has led to innumerable modelling efforts in many fields. Supercomputers have allowed us to consider the behavior of systems seemingly too complex for other approaches. One of those systems is climate. Not surprisingly, there are many problems involved in modelling climate. For example, even supercomputers are inadequate to allow long-term integrations of the relevant equations at adequate spatial resolutions. At presently available resolutions, it is unlikely that the computer solutions are close to the solutions of the underlying equations. In addition, the physics of unresolved phenomena such as clouds and other turbulent elements is not understood to the extent needed for incorporation into models. In view of those problems, it is generally recognized that models are at present experimental tools whose relation to the real world is questionable.
While there is nothing wrong in using those models in an experimental mode, there is a real dilemma when they predict potentially dangerous situations. Should scientists publicize such predictions since the models are almost certainly wrong? Is it proper to not publicize the predictions if the predicted danger is serious? How is the public to respond to such predictions? The difficulty would be diminished if the public understood how poor the models actually are. Unfortunately, there is a tendency to hold in awe anything that emerges from a sufficiently large computer. There is also a reluctance on the part of many modellers to admit to the experimental nature of their models lest public support for their efforts diminish. Nevertheless, with poor and uncertain models in wide use, predictions of ominous situations are virtually inevitable--regardless of reality.
Such weak predictions feed and contribute to what I have already described as a societal instability that can cascade the most questionable suggestions of danger into major political responses with massive economic and social consequences. I have already discussed some of the reasons for this instability: the existence of large cadres of professional planners looking for work, the existence of advocacy groups looking for profitable causes, the existence of agendas in search of saleable rationales, and the ability of many industries to profit from regulation, coupled with an effective neutralization of opposition. It goes almost without saying that the dangers and costs of those economic and social consequences may be far greater than the original environmental danger. That becomes especially true when the benefits of additional knowledge are rejected and when it is forgotten that improved technology and increased societal wealth are what allow society to deal with environmental threats most effectively. The control of societal instability may very well be the real challenge facing us.
Richard S. Lindzen
http://www.cato.org/pubs/regulation/regv15n2/reg15n2g.html
