Global warming has serious effects

Busloads of excited tourist disembark every day outside Tom's Restaurant at 2880 Broadway in Mnahattan. They have come to render homage to the greasy spoon of Sienfeld sitcom fame, and they are absolutely unaware of an infinitely more important program under way upstairs on the seventh floor. There, James E. Hansen, Cheif of NASA's Goddard Institute for Space Studies and the adjunct professor of geological sciences at Columbia University, leads a team of scientist assessing the climatic- and possibly climatic -fate of this planet as it spins into the third millennium.

Aside from the receding threat of nuclear war, no issue is more vital than the occuying Jim Hansen and his Goddard group; climate change, popularly known as the greenhouse effect, with it's potencially devastating impacts on nature and civilization. At the current rate of global warming, and as envisioned by climatologists, life on earth is hurtling toward conditions never before experienced.

By the year 2050, the global temperature could 3 degrees Fahrenheit warmer than it is now. It has not been that hot for nearly 200,000 years, a time well before modern humans evolved. By 2075, a 5-degree jump would make the planet the hottest in 4 million years, and by the end of the coming century the earth could be as hot as it was 65 milion years ago, when the dinosaurs disappeared.

Rapid heating on this scale will change the very face of the planet and cause chaos for the global environment, the economy, and politics. Glaciers will melt, and as seas heat and expand, the ocean will rise, drowning low-lying island nations and coastlines. Say sayonara to the Maldives, the Pacific atolls, Bangladesh, the Nile River delta, and much of the East and Gulf coasts of the United States. Tens of millions of people will be forced to move, and move again, in a kind of endless caravan, bearing conflict and disease. Adapted to specific climate zones could shift 400 miles north by the end of the next century-far faster than trees and other plants spread after the retreat of the last glacier-and many species will become extinct. Old forests will burn, farmland will succumb to drought, and floods will increase.

As Wallace Broecker, a geochemist at Columbia University's Lamont-Doherty Earth Observatory, warned in the late 1980's, "Earth's climate does not respond in a smooth and gradual way; rather, it responds in sharp jumps. These jumps appear to involve large-scale reorganizations of the Earth system. If this reading of the natural record is correct, then we must consider the possibility that the major responses of the system to our greenhouse provocation will come in jumps whose timing and magnitude are unpredictable. Coping with this type of change is clearly a far more serious matter than coping with a gradual warning."

By Robert H. Boyle, Audubon