As delegations from more than 150 countries were busy lobbying in Kyoto two months back in December, to discuss international controls on carbon dioxide emissions to mitigate a putative future global warming, climate scientists from Europe and North America warned that there was still no scientific consensus on global warming and that action based solely on unverified computer calculations was premature.

In a document called the “Leipzig Declaration,” more than 140 climate scientists stated that “most scientists now accept the fact that actual observations from earth satellites show no climate warming whatsoever,” and noted that this result was strongly at odds with results from climate models.

Why the rush to judgment? they asked. Climate model forecasts of global warming have been steadily reduced since 1990, as the models themselves have improved. Should climate models improve to the point of adequately accounting for clouds, water vapor, solar effects, and other factors that strongly affect climate, the warming forecasts will likely diminish even further, and may become insignificant. More time and research is needed before governments can proceed with any confidence.

The Leipzig Declaration characterizes restrictions called for in the Global Climate Treaty as economically unrealistic and politically suicidal. It points out that, under the Treaty, “stabilization” would mean cutting worldwide energy use by 60 to 80 percent, bringing economic activity to a halt.

“Energy is essential for all economic growth,” the scientists said. “In a world in which poverty is the greatest social pollutant, any restriction on energy use that inhibits economic growth should be viewed with caution. For this reason, we consider carbon taxes and other drastic control policies — lacking credible support from the underlying science — to be ill-advised.”

The Leipzig Declaration emerged from a conference, “The Greenhouse Controversy,” cosponsored by The Science & Environmental Policy Project and the European Academy for Environmental Affairs in Leipzig, Germany, in November 1995. The statement was revised in 1997 and currently has more than 140 endorsements from climate scientists, with more coming in.

According to physicist S. Fred Singer, president of The Science & Environmental Policy Project and former Director of the U.S. Weather Satellite Service, the claims of scientific consensus have been laid to rest in the last few months in articles in the journal Science, in newspapers like the Wall Street Journal, the Toronto (Canada) Globe & Mail, and the Washington Times, in the Austrian newsweekly Profil, and in broadcast documentaries, such as one that recently aired on Australian public television. “There is no scientific consensus,” said Singer, “which means the responsibility for ill-founded policies will rest with the politicians alone.”


As independent scientists researching atmospheric and climate problems, we — along with many of our fellow citizens — are apprehensive about the Climate Treaty conference scheduled for Kyoto, Japan, in December 1997. This gathering of politicians from some 160 signatory nations aims to impose — on citizens of the industrialized nations, but not on others — a system of global environmental regulations that include quotas and punitive taxes on energy fuels.

Fossil fuels provide today’s principal energy source, and energy is essential for all economic growth. Stabilizing atmospheric carbon dioxide — the announced goal of the Climate Treaty — would require that fuel use be cut by as much as 60 to 80 percent — worldwide!

In a world in which poverty is the greatest social pollutant, any restriction on energy use that inhibits economic growth should be viewed with caution. We understand the motivation to eliminate what are perceived to be the driving forces behind a potential climate change; but we believe the emerging Kyoto protocol — to curtail carbon dioxide emissions from only part of the world community — is dangerously simplistic, quite ineffective, and economically destructive to jobs and standards-of-living.

More to the point, we consider the scientific basis of the 1992 Global Climate Treaty to be flawed and its goal to be unrealistic. The policies to implement the Treaty are, as of now, based solely on unproven scientific theories, imperfect computer models — and the unsupported assumptions that catastrophic global warming follows from the burning of fossil fuels and requires immediate action. We do not agree. We believe that the dire predictions of a future warming have not been validated by the existing climate record. These predictions are based on nothing more than theoretical models and cannot be relied on.

As the debate unfolds, it has become increasingly clear that — contrary to the conventional wisdom — there does not exist today a general scientific consensus about the importance of greenhouse warming from rising levels of carbon dioxide. In fact, many climate specialists now agree that actual observations from weather satellites show no global warming whatsoever — in direct contradiction to computer model results.

Historically, climate has always been a factor in human affairs — with warmer periods, such as the medieval “climate optimum,” playing an important role in economic expansion and in the welfare of nations that depend primarily on agriculture. Colder periods have caused crop failures, and led to famines, disease, and other documented human misery. We must, therefore, remain sensitive to any and all human activities that could affect future climate.

However, based on all the evidence available to us, we cannot subscribe to the politically inspired world view that envisages climate catastrophes and calls for hasty actions. For this reason, we consider the drastic emission control policies likely to be endorsed by the Kyoto conference — lacking credible support from the underlying science — to be ill-advised and premature.

This statement is based on the International Symposium on the Greenhouse Controversy, held in Leipzig, Germany on Nov. 9-10, 1995, and in Bonn, Germany on Nov. 10-11, 1997. For further information, contact the Europaeische Akademie fuer Umweltfragen (fax +49-7071-72939) or The Science and Environmental Policy Project in Fairfax, Virginia (fax +1-703-352-7535).