NCPA - National Center for Policy Analysis


October 17, 2007

Global warming doesn't matter except to the extent that it will affect life -- ours and that of all living things on Earth.  And contrary to the latest news, the evidence that global warming will have serious effects on life is thin.  Most evidence suggests the contrary, says Daniel B. Botkin, president of the Center for the Study of the Environment and professor emeritus in the Department of Ecology, Evolution, and Marine Biology at the University of California, Santa Barbara.

Case in point:

  • This year's United Nations report on climate change and other documents say that 20 percent to 30 percent of plant and animal species will be threatened with extinction in this century due to global warming -- a truly terrifying thought.
  • Yet, during the past 2.5 million years, a period that scientists now know experienced climatic changes as rapid and as warm as modern climatological models suggest will happen to us, almost none of the millions of species on Earth went extinct.
  • The exceptions were about 20 species of large mammals (the famous megafauna of the last ice age -- saber-tooth tigers, hairy mammoths and the like), which went extinct about 10,000 to 5,000 years ago at the end of the last ice age, and many dominant trees and shrubs of northwestern Europe.
  • But elsewhere, including North America, few plant species went extinct, and few mammals.

We're also warned that tropical diseases are going to spread, and that we can expect malaria and encephalitis epidemics, says Botkin.  But scientific papers by Prof. Sarah Randolph of Oxford University show that temperature changes do not correlate well with changes in the distribution or frequency of these diseases; warming has not broadened their distribution and is highly unlikely to do so in the future, global warming or not.

Source: Daniel B. Botkin, "Global Warming Delusions," Wall Street Journal, October 17, 2007.


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