Certainly Uncertain about Climate Change

Published October 1, 1999

Even as summer temperatures heated up as they normally do, opinion polls showed that Americans were tuning out global warming by large margins. Science suggests they have good reason to do so.

I am not a scientist . . . but I do listen to what they say. While there are many competing opinions about the potential for human-induced climate change, it is possible to find consensus on some important issues.

For instance, scientists are unanimous in the belief that a very large number of uncertainties remain about our understanding of the climate. Moreover, they agree that there is no known connection between long-term climate change and short-term weather events like heat waves, droughts, or hurricanes.

Here’s what some notable observers have to say:

  • Michael Hayes, climate specialist at the National Drought Mitigation Center in Lincoln, Nebraska, was asked about current drought conditions plaguing much of the nation’s breadbasket. “Individual events I don’t see as necessarily related to the larger phenomena.”
  • In its July 26 issue, Time magazine science correspondent Dick Thompson noted, “You can’t link a specific event–this heat wave–to climate change.”
  • On CNN, Georgia Tech meteorological scientist Jim St. John added, “A heat wave is a heat wave. We’ve always had them in summer months, and they don’t necessarily tell us anything about climate change.”
  • University of California professor Brian Fagan highlighted concerns about weather and global warming in a New York Times op-ed. “Yes, it’s hot. But it’s been hot (or cold or dry or wet) before.” Fagan listed a series of weather-related events beginning in 2180 BC that “suggest short-term extremes are nothing new.”
  • Oregon’s State Climatologist, George Taylor, president of the American Association of State Climatologists, wrote in the Salt Lake Tribune, “there is insufficient knowledge of the magnitude of natural climatic variations, like ocean currents and solar variation, to gauge how large the human impact is by comparison.”
  • Dr. John Christy, a University of Alabama climatologist who does work for NASA, recently said “attempting to understand the climate is not aided by the fixation on extreme events as indicators of climate change. Our limited knowledge of the rates of occurrence and the ability to publicize even marginal extremes to fantastic proportions without looking at history is misleading.”
  • NASA’s Dr. James Hansen, the so-called father of global warming, recently raised questions about our understanding of greenhouse gases. He has substantially revised his earlier global warming forecasts, saying they grossly overstated the growth rate of emissions and their impact. “Our understanding of greenhouse gases is not all that good,” he explained.

While uncertainty exists, the possibility of human-induced climate change is a serious issue, one that merits a high level of concern and a thoughtful response. We do a serious disservice to the complexity and seriousness of the matter to make selective references to hot summer weather and declare that such snapshots-in-time must somehow be the result of human-induced climate change.

Perhaps drought-stricken Maryland farmer Vaughn Harshman offered the best analysis of the matter when he commented, “Global warming doesn’t mean a thing to me. I can’t blame it on anything. Weather always fluctuates.”

Glenn F. Kelly is the Executive Director and Chief Executive Officer of the Global Climate Coalition (GCC), an organization of private companies and trade associations collectively representing more than 230,000 firms established in 1989 to coordinate the active involvement of U.S. business in the scientific and policy debates concerning global climate issues.