POLITICAL SCENE

January 1998

The Great Global El Nino Ozone Warming Debate

For the past several months, global climate change has been the top environmental issue facing President Clinton and Congress. Interest may have peaked with the December meeting of the signatory nations to the United Nations Framework Convention on Climate Change in Kyoto, but the issue will continue to garner attention as Congress debates the merits of reducing carbon emissions. In addition, the administration has recently launched a national assessment of the United States' vulnerability to climate change.

In a situation not often repeated, scientific issues have been at the center of the political debate over climate change. Not surprisingly, public interest in that debate has not translated into public understanding of the science. One can bemoan the woeful state of scientific literacy in this country, but in their defense, the public faces the additional hurdle of the similarity of long- term climate change to a range of other atmospheric issues currently being debated or addressed.

With a strong knowledge of Earth and its processes, geoscientists can play a role in improving public understanding of climate change, but along with that role comes a responsibility to clarify these related issues in our own minds and to recognize the limits of our understanding. Participating in the ongoing national assessment might be one way that geoscientists can improve their own understanding and contribute to better policy making.

Atmospheric issues

An article by Willett Kempton in the November 1997 issue of the journal, Environment, focused on public perception of the climate change issue. Polling data reported in the article showed concern to be high, but understanding low, in the general population. Follow-up interviews were conducted to get beyond the poll responses and find out why people felt the way they did about climate change. Most people were trying to put it in the context of more familiar atmospheric phenomena, such as air pollution, local weather, and even ozone depletion (which, after 20 years of press coverage, has joined the pantheon of widely recognized environmental issues).

These responses, not at all surprising, reflect the fact that at the present time, four major policy issues involving the atmosphere are hot environmental topics: the Kyoto conference on long-term global climate change, ongoing efforts to combat stratospheric ozone depletion, new EPA regulations on tropospheric ozone smog, and mitigation efforts being considered to prepare for the strongest El Nino in 20 years. Many scientists, let alone the general public, may find it hard to distinguish between decreasing stratospheric ozone and increasing tropospheric ozone smog or between long-term global climate change trends and the seasonal to interannual oscillations represented by El Nino.

Although the principal causes of each of these phenomena differ, the relationships between them are complex. A given atmospheric component can have a beneficial effect in one case and a detrimental effect in another. For example, sulfate aerosols increase the reflectivity of sunlight, thus reducing the greenhouse effect and global warming. Does that mean that sulfate aerosols, pollutants that contribute to acid rain and smog, are good? Clearly, none of these issues can be examined or understood in isolation.

What geoscientists can do

A wide range of geoscientists are involved in gathering data on present and past climate change -- from geomorphologists studying land-surface patterns to paleontologists studying shifts in faunal patterns, and from geochemists studying carbon budgets and background levels to paleoclimatologists looking at ice cores. The list goes on, but all geoscientists can contribute to better public understanding. In addition to familiarity with earth processes and complex natural systems, geoscientists are used to working with a variety of timescales -- they can take the long view and see trends for what they are and are not. For example, the current rate of warming may be unprecedented in the last 10,000 years but not, as it turns out, in the last 20,000 years since the emergence from the last glacial maximum. A string of hot summers does not necessarily translate into long-term climate change, just as the intensity of the current El Nino may be unrelated to higher concentrations of atmospheric carbon dioxide.

But being far-sighted does not mean we have clear vision -- the largest carbon sinks, such as limestone formation, operate on timescales too long to react to any near-term fluxes, man-made or otherwise. After all, concern over climate change is not concern over the planet's survival (that is left to the asteroid-impact crowd) nor even for our species (see nuclear winter) but for our own standard of living. Because the discussion of climate change is focused on social and economic impacts, it is clear that physical science can only take us so far in understanding what should be done or to foretell the consequences of various mitigation strategies. To view the larger picture, geoscientists will have to learn from biologists and social scientists while still providing their own perspective.

National assessment

Geoscientists can learn more about the climate change issue and become involved in the policy-making process by participating in regional workshops being organized as part of a national effort to assess regional vulnerabilities to climate change. Eight of these workshops were held in 1997. In 1998, workshops will focus on the Midwest, Texas/Southern Great Plains, Upper Great Lakes, Gulf Coast, California, Central Appalachia, Hawaii and Pacific Islands, Metropolitan East Coast, Southeast Coast and Caribbean, and Rocky Mountains/Great Basin. For further information about the workshops, visit the U.S. Global Change Research Program web site at www.usgcrp.gov.

At a forum in Washington, D.C., to kick off the national assessment, Presidential Science Advisor Jack Gibbons emphasized the need to shift from observing and documenting change in Earth's physical systems toward an emphasis on broader efforts to understand what climate change means to human and biological systems, including the social and economic ramifications. Such a shift in emphasis represents an opportunity for many geoscientists involved in the industries that would be affected by mitigation efforts. But it is also important that such a shift in emphasis does not push geoscientists to abandon efforts to understand past climate change as they seek to put the current changes into historical perspective.

Whatever the focus of federal climate change efforts, it is imperative that geoscientists remain involved in the process, informing themselves and the public at large as well as policy makers. Only then can we begin to clarify the issues at stake and work toward a national consensus on how to assess and address future climate change.