Issue of
May 21, 1997

Ecologists warn President
Clinton: Rapid climate
change due to global warm
ing could disrupt ecosystems
society depends on

BY JANET BASU

Twenty-one of the nation's leading experts on ecological systems and climate, including four Stanford faculty members, sent a letter on Tuesday, May 20, to President Clinton urging him to take a "prudent course" in upcoming global climate change negotiations. The scientists warn that the problem is not so much that the climate may get warmer over the next century, but that the changes in temperature and rising sea levels could be so rapid that plants, animals and other species will be unable to adapt.

They warn that the resulting breakdown of ecosystems could lead to disturbances with major effects on human populations: fires, floods, droughts, storms, erosion and outbreaks of pests and pathogens, plus losses in fresh water, soil, forests, fisheries and other resources that human society depends on.

"The accompanying letter to President Clinton comes from a group of ecologists from around the country who have studied the potential impacts of global change on biotic systems. The signers include the leading international experts on many particular dimensions of this problem," said Harold Mooney, Stanford professor of biological sciences and the organizer of the effort. "They all have deep concerns about the ecological consequences of rapid climatic change."

Among the signers are Mooney, Paul Ehrlich and Peter Vitousek, all Stanford ecologists, and Stanford climate impact expert Stephen Schneider. Also included are Jane Lubchenco of Oregon State University, past president of the American Association for the Advancement of Science, and ecologists and climate experts from many of the nation's top universities and research centers. Seven are members of the National Academy of Sciences and five are past presidents of the Ecological Society of America. (A complete list is printed below.)

The letter is being sent as the Clinton administration prepares instructions to the State Department for international negotiations on ways to reduce greenhouse gas emissions and other activities that contribute to global warming. The United States and other countries are developing a protocol to strengthen the U.N. Framework Convention on Climate Change, and are expected to approve that protocol at a climate summit in Kyoto, Japan, in December.

Copies of the letter were sent to Vice President Al Gore; Secretary of State Madeleine Albright and State Department Under Secretary Timothy Wirth; Agriculture Secretary Dan Glickman; Energy Secretary Federico Peña; Interior Secretary Bruce Babbit; Carol Browner, administrator of the Environmental Protection Agency; and James Baker, administrator of the National Oceanic and Atmospheric Administration.

No distant problem

It will not be enough to set a distant date to stabilize greenhouse gases, as some policy makers have advised, the ecologists warn. If current levels of greenhouse gas emissions continue to rise, they are projected to lead to a rate of climate change significantly faster than at any time during the past 10,000 years.

The scientists call for a "prudent course" that would "limit climate change to the lowest rates feasible, given emissions that have already occurred." That would slow global warming to no more than 1 degree celsius per century, according to a 1995 report by the Intergovernmental Panel on Climate Change (IPCC). But if humans continue to add carbon dioxide and other gases, the IPCC projects an increase of 1 to 3.5 degrees celsius (2 to 6 degrees Fahrenheit) over the next 100 years - with correspondingly greater changes at higher latitudes, including much of the United States.

The scientists said there is little data about the effects of such a rapid change - nothing on this scale has occurred in Earth's recent history. But they said scientists do know that climate change requires many species to shift their ranges for food and shelter. In today's world, pollution, disturbance of habitats and other human alterations of the landscape give many species less room to make those moves. In many cases, damage from pollution and human encroachment already have left important ecosystems less resilient and able to adapt to change.

In the United States, the scientists said, rapid climate change could mean the widespread death of trees, followed by wildfires and a replacement of forests by grasslands. National parks and forests could become inhospitable to the rare plants and animals that are preserved there - and where the parks are close to developed or agricultural land, the species themselves may disappear for lack of another safe haven. Worldwide, fast-rising sea levels would inundate the marshes and mangrove forests that protect coastlines from erosion and serve as filters for pollutants and nurseries for ocean fisheries.

"The more rapid the rate [of change], the more vulnerable to damage ecosystems will be," the scientists told the president. "We are performing a global experiment [with] little information to guide us."

Following is a complete list of the signatories to the letter:

Fakhri Bazzaz, Harvard University; Janine Bloomfield, Environmental Defense Fund; F. S. Chapin III, University of California-Berkeley; James Clark, Duke University; Margaret B. Davis, University of Minnesota; Paul Ehrlich, Stanford University; Christopher Field, Department of Plant Biology, Carnegie Institution of Washington, located at Stanford; Jerry F. Franklin, University of Washington; Diana Wall Freckman, Natural Resource Ecology Laboratory of Colorado State University; Gene Likens, Institute for Ecosystem Studies of the Cary Arboretum, Millbrook, N.Y.; Jane Lubchenco, Oregon State University; Pamela A. Matson, University of California-Berkeley; Harold Mooney, Stanford University; Louis F. Pitelka, Appalachian Environment Laboratory at Frostburg, Md.; David S. Schimel, University Center for Atmospheric Research in Boulder, Colo.; William H. Schlesinger, Duke University; Steve Schneider, Stanford University; Herman H. Shugart, University of Virginia; Boyd Strain, Duke University; G. David Tilman, University of Minnesota; Peter Vitousek, Stanford University. SR