Curbing global warming: is the cost too high?

• Author: Weidenbaum, Murray L.

"... A carbon tax sufficient to stabilize emissions at 1990 levels by 2010 would slow down real wage growth, worsen the distribution of income, and make Americans feel as if they were living through the oil price shocks of the 1970s and early 1980s all over again."

The most controversial environmental issue facing the U.S. today is hot to respond to the pressure to fight global warming by substantially reducing emissions of carbon dioxide ([CO.sub.2]), the leading greenhouse gas. This was demonstrated anew at the meeting in Kyoto, Japan, in December, 1997, to sign a successor treaty to the United Nation's voluntary 1992 Framework Convention on Climate Change, with much of the responsibility being placed on the developed nations to to cut their use of fossil fuels.

It is with some reluctance that I suggest that, before acting, we should examine both the seriousness of the problem and the feasibility of the suggested solution. On the surface, my proposal would not seem to be exactly outrageous.

However, it is used to have to acknowledge that we in the U.S. have reached the point where it is personally--and professionally--dangerous, if not foolhardy, to criticize in any way any proposal to "do more for the environment." Just raising a question is guaranteed to result in the intrepid individual being castigated as caring more about dollars than ecology and having his or her viewpoint dismissed as defending "the polluters." I will save for another day the task of explaining why each of us is a "polluter," either as a producer, a consumer, or both.

Nevertheless, let us begin by examining the question of global warming or, to use the more neutral (also more ambiguous) term, climate change. Proponents of quick action rely for support on a widely quoted passage from a 1995 report of the UN's Intergovernmental Panel on Climate Change (IPCC), an impressive group of scientists and government officials: "The balance of evidence suggests that there is a discernible human influence on global climate." That is such a modest and vague statement that one has to wonder why people rely so heavily on it to support specific proposals for action.

In fact, that modest statement on "discernible human influence" is preceded by a caveat which is quoted far less widely: "Our ability to quantify the human influence on global climate is currently limited because the expected signal is still emerging from the noise of natural variability and because there are uncertainties in key factors." The report then goes on to tell about those technical uncertainties.

Yet another shortcoming of the IPCC summary has been identified. Normally, a summary conforms to the body of the report. Apparently, that was not the procedure followed by those who edited the document. It seems that the editor, after writing the summary, went back and deleted sections of the report that did not conform to it. Here are two of the deletions: "None of the studies cited above has shown clear evidence that we can attribute the observed [climate] changes to ... increases in greenhouse gases." Also, "No study to date has positively attributed all or part [of the climate change observed to date] to anthropogenic causes."

My understanding of all this is that knowledgeable scientists, including those who advocate tough action, admit that great uncertainty exists in the chain of causation from emissions of [CO.sub.2] by human (anthropogenic) activities to increases in global temperature. This relationship is far from simple.

It is not a question of totally eliminating...