Myths of Global Warming

Commentary by H. Sterling Burnett

The Clinton administration has decided to commit the United States to finalizing a treaty in December 1997 that would impose internationally enforceable limits on the production of greenhouse gases, primarily carbon dioxide (CO2). That decision was based on the belief that global warming is significant, that humans are its primary cause and that only immediate government action can avert disaster. Before embarking on a course of action that would do little environmental good and great economic harm, the public and Congress should examine the myths that are driving ongoing treaty negotiations.

One myth is that the earth is indisputably warming. While ground-level temperature measurements suggest the earth has warmed between 0.3 and 0.6 degrees Celsius since 1850, global satellite data, the most reliable of climate measurements, show no evidence of warming during the past 18 years. Even if the earth's temperature has increased slightly, the increase is well within the natural range of known temperature variation over the last 15,000 years. Indeed, the earth experienced greater warming between the 10th and 15th centuries - a time when vineyards thrived in England and Vikings colonized Greenland and built settlements in Canada.

A second myth is that scientists agree that humans are causing global climate change. The scientific experts most directly concerned with climate conditions reject the theory by a wide margin. For instance, a Gallup poll found that only 17 percent of the members of the Meteorological Society and the American Geophysical Society think that the warming of the 20th century has been a result of greenhouse gas emissions - principally CO2 from burning fossil fuels. Only 13 percent of the scientists responding to a survey conducted by the environmental organization Greenpeace believe catastrophic climate change will result from continuing current patterns of energy use. In addition, more than 100 noted scientists, including the former president of the National Academy of Sciences, signed a letter declaring that costly actions to reduce greenhouse gases are not justified by the best available evidence.

While atmospheric carbon dioxide has increased by 28 percent over the past 150 years, human-generated carbon dioxide could have played only a small part in any warming, since most of the warming occurred prior to 1940 - before most human-caused carbon dioxide emissions.

The third myth is that the consequences of near-term inaction could be catastrophic and, thus, immediate government action is warranted. A 1995 analysis by climatologists T.M.L. Wigley, R. Richels and J.A. Edmonds concluded that the world's governments can wait up to 25 years to take action with no appreciable negative effect on the environment. They found that governments can cut emissions now to approximately 9 billion tons per year or wait until 2020 and cut emissions by 12 billion tons per year. Delaying action until 2020 would yield only an insignificant temperature rise of 0.2 degrees Celsius by 2100.

In short, the government has time to gather more data, and industry has time to devise new ways of lessening greenhouse gas emissions.

The fourth myth driving current treaty negotiations is that anticipated global warming will cause all manner of environmental disasters including, higher ocean levels and increased hurricane activity. Reputable scientists, including those working on the Intergovernmental Panel on Climate Change (IPCC) reject this myth.

Sea levels are rising around the globe, though not uniformly. In fact, sea levels have risen more than 300 feet over the last 18,000 years - far predating any possible human impact. Rising sea levels are natural in between ice ages. Contrary to the predictions of global warming theorists, the current rate of increase is slower than the average rate over the 18,000-year period.

Periodic media reports link human-caused climate changes to more frequent tropical cyclones or more intense hurricanes. But recent data show no increase in the number or severity of tropical storms. Since the 1940s the National Oceanographic and Meteorological Laboratory has documented a decrease in both the intensity and number of hurricanes. From 1991 through 1995, relatively few hurricanes occurred, and even the unusually intense 1995 hurricane season did not reverse the downward trend. In addition, the 1996 IPCC report on climate change found a worldwide significant increase in tropical storms unlikely. Most scientists agree that any regional changes in hurricane activity will continue to occur against a backdrop of large yearly natural variations.

As scientists expose the myths concerning global warming, the fears of an apocalypse should subside. So rather than legislating in haste and ignorance and repenting at leisure, our government should maintain rational policies, based on science and adaptable to future discoveries.