Turning Down the Heat
With temperatures rising worldwide, climatologists predict a planetary emergency. We have the means to avert the crisis, but do we have the political will?
by James R. Udall

IN SCIENTIFIC CIRCLES, Columbia University geochemist Wallace Broecker is regarded as a "big thinker," someone who, in the words of a colleague, "has more ideas in a week than most people have in a lifetime." Recently Broecker has been pondering global warming. In scientific journals and congressional testimony, he has stated that the phenomenon represents a "gigantic and dangerous experiment" and "a form of Russian roulette."

Broecker is hardly alone. The National Academy of Sciences recently warned President Bush that "global environmental change may well be the most pressing international issue of the next century," adding, "the future welfare of human society is . . . at risk."

Their alarm is based on hard, cold data. In February, British scientists reported that the six warmest years in the last hundred have been, in descending order, 1988, 1987, 1983, 1981, 1980, and 1986. This finding is consistent with the greenhouse-effect theory, which holds that a buildup of heat-trapping gases in Earth's atmosphere is warming the planet. Irrefutable evidence of global warming may be available within a decade, according to climatologist Stephen Schneider of the National Center for Atmospheric Research. If such evidence turns up, it could be a turning point in a long series of events that began in 1769, the year a Scottish inventor named James Watt perfected the coal-fired steam engine and sent the Industrial Revolution chug-chug-chugging on its way.

Absent a worldwide effort to reduce greenhouse-gas emissions, an average temperature rise of 3 to 9 degrees Fahrenheit is likely by 2050, according to Schneider and other scientists. Such a radical increase is guaranteed to trigger economic and social upheaval on a grand scale. Its ecological impacts--farms turning into deserts, ice caps melting, sea level rising, entire forests dying--will be catastrophic. Global warming could also be the last straw for untold thousands of species already stressed by habitat disruption, as well as others that now seem secure. A planet without polar bears? The thought may be distressing to contemplate, but it's a real possibility.

Global warming seems destined to become a genuine planetary emergency, a crisis born of one ineluctable reality: Modern societies have been forged from, and are sustained by, fossil fuels--oil, coal, and natural gas. Burning these fuels releases immense quantities of carbon dioxide (CO₂). Not a "pollutant" that can be scrubbed, trapped, or otherwise eliminated, CO₂ is a fundamental byproduct of the combustion process. Thus, global warming has been simmering for a long time. Until recently, though, it has been one of the hidden costs of progress.

DEVISING A STRATEGY TO COMBAT GLOBAL WARMING is not like finding a cure for cancer. The ailment's causes are known. Coming up with a prescription for a cure is child's play; filling it, though, is a Herculean task. Any attempt to halt climatic change must be global in scope and must persist for decades, even centuries. In one fashion or another, these efforts will affect the lives of nearly everyone on the planet.

In recent months the Beijer Institute in Stockholm, United Nations Environment Programme, World Meteorological Organization, Worldwatch Institute, World Resources Institute, Environmental Protection Agency, Sierra Club, and Woods Hole (Massachusetts) Research Center have outlined strategies for combating climatic change. Each group independently concluded that the threat of global warming is so grave that action should be taken immediately.

If the computer models are right, we are irrevocably committed to some measure of change; one to three degrees of warming are "in the bank" from past greenhouse emissions. To this, add four-tenths to one degree for each decade that emissions continue at current rates. "If our projections are correct, during the next century Earth may warm 10 to 40 times faster than it did after the last ice age," Schneider says.

Greenhouse expert George Woodwell, director of the Woods Hole Research Center, believes the immediate goal should be to slow the rate of warming as a first step toward halting it. This will buy precious time--to do more research, to anticipate problems before they occur, and to devise mitigation projects, such as breeding drought-resistant wheat, building sea walls, and transplanting endangered species.

Woodwell, Schneider, and other prominent scientists agree that we should begin by taking steps that make sense for their own sake--things we wouldn't regret even if global warming doesn't occur. "There are certain initiatives we can take that will buy us some planetary insurance and that will have other ancillary benefits as well," Schneider says.

Such initiatives include launching a crash program of greenhouse research; banning chlorofluorocarbons (CFCs), another greenhouse gas; implementing an ambitious national energy-efficiency plan; redoubling efforts to use renewable-energy sources; starting a worldwide reforestation campaign (trees sponge CO₂ from the air); and doing everything in our power to help other countries achieve their development goals with renewable rather than fossil fuels.

Today's greenhouse research efforts are woefully underfunded. "Only a trifling percentage of the federal budget is spent on global-change research," Woodwell says. "Given the stakes, this is immensely shortsighted."

In particular, scientists say, we must improve existing climate models. We have a compelling need to know with more certainty how fast the warming will occur and what its specific impacts will be on various parts of the globe. Will the Colorado River shrivel up? Is the Midwest a bull's-eye for droughts? Will the sea-level rise be feet--or yards?

Investigating the interactions between global warming, the climate, and the biosphere is also imperative. A bewildering variety of climatic and biotic feedbacks could amplify--or reduce--the warming. For example, climate models predict that the greenhouse effect will increase the world's cloud cover. But whether more clouds will exacerbate or alleviate the warming is unclear. Global warming also has the potential to affect plankton populations. Since these microscopic aquatic plants and animals now utilize huge amounts of CO₂, even minor changes in their numbers could have a dramatic impact on the rate of warming. In a recent Scientific American article, Woodwell suggested a third possibility--that global warming could feed on itself by, for instance, speeding up the decay of organic matter, increasing the amount of CO₂ released in that process. In short, the range of uncertainty remains disconcertingly broad.

"We've got to get the planet into intensive care, start to monitor its vital signs," says John Eddy of the University Corporation for Atmospheric Research. A National Institute for the Environment is needed to coordinate scientific initiatives, says Columbia's Broecker: "We must get the best people together, identify the problems, brainstorm a research program, and fund it."

Scientists believe that CO₂ will be responsible for half the expected warming. The other half is expected to come from methane (emitted by termites, rice paddies, livestock, and coal deposits), nitrous oxide (from coal combustion and fertilizers), CFCs, and other greenhouse gases. Any control strategy must target these gases as well as CO₂.

Of all the second-string culprits, CFCs, most commonly used as refrigerants and as blowing agents for foam insulation and packaging, have received the most public attention. Not only are CFCs, volume for volume, a greenhouse gas 10,000 times more potent than CO₂, they destroy the ozone shield that protects Earth from harmful ultraviolet radiation. The 1987 Montreal Protocol, signed by 46 nations including the United States, mandates 50 percent reductions in CFC production by 1998. Recently, however, scientists have discovered that we have already destroyed as much ozone as the treatymakers assumed we would lose by the year 2050. Since substitutes exist, many experts are now saying CFCs should be phased out completely.

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