NCPA - National Center for Policy Analysis


February 2, 2006

As used by the media, "global warming" refers to the theory not only that the earth is warming, but doing so because of human industrial activity. Measuring average global temperature is not an easy matter. Scientists, naturally, have to rely on record keepers in decades past, using different instruments, to produce what has become the conventionally accepted estimate of a one-degree rise over the past century, says Holman W. Jenkins, Jr. of Wall Street Journal.

But even if a change is measured, how do we know it's human induced? Consider:

  • The climate is a vast, complex and poorly understood system; scientists must resort to elaborate computer models to address a multiplicity of variables and feedbacks before they can plausibly suggest that the net effect of increased carbon dioxide is the observed increase in temperature.
  • Myanna Lahsen, an anthropologist who spent several years observing and interviewing staff at the National Center for Atmospheric Research, shows in a new paper that even climate modelers themselves, who appreciate better than anyone the limits of their work, nonetheless slip into unwarranted certainty in public.
  • Today's debate over global warming revolves almost exclusively around the status and motives of spokespersons for opposing viewpoints, rather than the science and its limits.

Tony Blair and many others recognize that the problems associated with climate change (whether human induced or natural) are the same old problems of poverty, disease and natural hazards like floods, storms and droughts. Money spent directly on these problems is a much surer bet than money spent trying to control a climate change process that we don't understand, says Jenkins.

Source: Holman W. Jenkins, Jr. "A Global Warming Worksheet," Wall Street Journal, February 1, 2006; and Myanna Lahsen, "Seductive Simulations? Uncertainty Distribution Around Climate Models," Social Studies of Science, Issue 35, Vol. 6, December 2005.

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