Adverse impacts of warming have been exaggerated

by William Yeatman on May 11, 2004

in Science

On May 3, the Cooler Heads Coalition hosted a Capitol Hill briefing entitled “The Impacts of Global Warming: Why the Alarmist View is Wrong.” The event allowed four leading experts to discuss the specific scientific research that has been done in their four particular fields: severe weather events, rising sea levels, tropical diseases, and mass species extinctions.

Dr. Madhav L. Khandekar, who recently retired from Environment Canada after a 25-year career as a research scientist, and who recently edited a special issue of the international journal Natural Hazards on extreme weather events, presented his views concerning the lack of connection between severe weather events and global warming. Khandekar specifically examined heat trends from Canada, thunderstorms and tornadoes in North America, and monsoons in Asia. He concluded that there has not been an increase in severe weather events and that the likelihood of increased incidences of extreme weather events in the next ten to twenty-five years remains very small at this time.

Professor Nils-Axel Morner, head of the Paleogeophysics and Geodynamics Department at Stockholm University and past president of the INQUA Commission on Sea Level Changes and Coastal Evolution, delivered an amusing and enthusiastic presentation examining sea level change. He pointed out that what has been predicted by computer models is not backed up by empirical evidence. Satellite measures, for instance, show no change in sea level over the past decade, which has led him to write in a peer-reviewed journal, “This implies that there is no fear of any massive future flooding as claimed in most global warming scenarios.” Much of the supposed rise, it seems, has actually been a shifting of the amount of water from one area of the globe to another.

Nor is Professor Morner worried about island nations drowning. He and his team did an exhaustive investigation of the claim made by the Intergovernmental Panel on Climate Change that the Maldive Islands in the Indian Ocean are at risk from sea level rise accelerated by global warming. He found considerable evidence that the sea level in the islands has fallen over the past 30 years, and that the islands and their people survived much higher sea levels in the past.

Next, Paul Reiter, a professor at the Institut Pasteur in Paris who specializes in the spread of vector-borne diseases, demolished the common claim that warmer temperatures play an important role in the spread of malaria and other mosquito-borne diseases. Reiter gave a brief historical excursus of the prevalence of malaria (or ague, as it was called in earlier centuries) in England during the Elizabethan Age, in Washington, D. C., and other northern climates during the Little Ice Age. Reiter remarked that the largest outbreak of malaria in the twentieth century occurred not in the tropics but in the Soviet Union in 1923-25, when there were more than 16 million cases and 600,000 fatalities. This figure includes 30,000 deaths in Archangel, which is above the Arctic Circle.

Reiter explained that malaria and other “tropical” diseases have more to do with living conditions than temperature. He cited his study that analyzed the Texas-Mexico border, where dengue fever was prevalent in Mexico and rare in Texas despite the similar environmental conditions. The only difference was living conditions. He also emphasized that many of the “experts” (such as physician Paul Epstein, who is not a medical researcher) expressing concern over global warming and tropical diseases are newcomers to the field and have not bothered to master the literature. Prof. Reiter concluded that climate is rarely relevant to the re-emergence of vector-borne diseases.

Patrick Michaels, professor of Environmental Sciences at the University of Virginia and a senior fellow at the Cato Institute, examined the claim that global warming threatens mass extinction of species. Michaels analyzed recent scientific articles that have been claimed as evidence that rising temperatures are reducing habitats for butterflies, penguins, polar bears, and toads. In each case, he showed that either temperatures were not rising in the specific habitats or habitat for the specific species had actually expanded. Michaels concluded that research has demonstrated that species range is affected by rising temperatures, but not in a way that helps the alarmist case.

The presenters on the panel were generally scathing about the quality of the IPCCs assessment reports in their fields of expertise. For instance, Prof. Reiter revealed that, the nine lead authors of the chapter discussing vector-borne diseases in the Second Assessment Report had published a total of six papers on the subject. The three leading critics of the chapter, including Prof. Reiter, had published over 550 scholarly papers. Prof. Morner has written in a peer-reviewed journal article that the IPCC chapter on sea-level rise represents “a low and unacceptable standard. It should be totally rewritten by a totally new group of authors chosen among the group of true sea-level specialists.”

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