By Tyrone Cashman

The world's political leaders, nation by nation, are waking up to the fact that while the old human/political/historical issues are still serious, there is a new issue. Till now, environmental problems have hovered on the edge of the consciousness of world leaders, pushed into the political arena, they felt, by scruffily-dressed, underemployed, and over-educated dreamers and troublemakers. Never has an environmental question been anything but a nuisance to a major political man or woman, a distraction from the "real issues": political, military, and economic power games.

But gradually it is becoming clear to a few world leaders that, while their attention has been on political, military, and economic power games, a menacing figure has slowly moved from the horizon (where it had looked like a harmless smudge) up to the edge of the political playground where it can be seen to be an angry giant capable of sweeping not only their games and their toys, but themselves, their children, and all their great, great grandchildren into oblivion. This giant is the combination of ozone depletion and global warming, coming as it does on the heels of a thousand previous assaults on natural ecosystems. For the first time the rhetoric that we could wipe out a great proportion of all life on Earth has become realistic.

A series of events:

1. In 1974, several American atmospheric scientists informed the U.S . government that the chlorofluorocarbons (CFCs) we use might harm the protective ozone layer. For four years, no response. Then very slow and minimal response.

2. In 1984-85, suddenly, without even the most pessimistic atmospheric scientists having guessed it, a huge hole in the ozone opened over the South Pole, exposing parts of South America, Australia, and New Zealand to high ultra-violet B (UV-B) radiation from the sun. Finally, a world meeting was called to ban CFCs on a rather slow timetable, by the year 2000. Many related chemicals that also cause ozone depletion were not even included in this phase-out.

3. Everyone was congratulating themselves that there had been a new thing, a world governmental response to an environmental problem. Today, due to high UV-B radiation under the ozone hole in Patagonia, there are stories of flocks of blind sheep led by blind shepherds.

4. In the intervening seven years, it was noted that the ozone layer had been depleted over the northern hemisphere by 4% to 8%. (An 8% depletion of ozone leads to 18% increase in UV -B radiation.)

5. Then, in the Fall of 1991, another jolt. Measurements over the Arctic showed that the potential for ozone-depletion in the northern hemisphere was much more severe than anyone had thought. Concentrations of ozone-depleting chemicals were so high that instead of a serious 4% to 8% depletion over Canada, Maine, Scandinavia, Scotland, and Russia, scientists estimated that ozone losses would be as high as 40% in the winter if certain weather patterns occurred. Concentrations of ozone depletors were so high that Michael Kurylo, NASA manager of upper-atmosphere research, said, "Everyone should be alarmed about this. It is far worse than we thought." This past year we were lucky. The weather did not produce the conditions necessary to produce an ozone hole. But the ozone-depleting chemicals remain in the atmosphere for decades. Next year or the year after, when conditions are right, we may be faced with a serious depletion in ozone over the northern latitudes during the winter and spring. In spring, plants are germinating and growing rapidly, and are especially vulnerable to damaging radiation. This is also the time when the vital oceanic phytoplankton, the single source of food for the entire aquatic food chain and the major carbon sink protecting us from global warming, is going through its reproductive bloom and is maximally sensitive to lethal UV-B radiation. The actual situation regarding depletion of the ozone layer is worse than the investigators' "worst case scenario."

Now let us add another global problem, the increase of global temperatures due to 100 years of heavy coal and oil use. We have been increasingly digging and pumping carbon compounds (coal and oil) out of the ground, where they do no one any harm. Then we vaporize them into carbon dioxide gas which traps the heat from yesterday's sunshine under a transparent blanket. Over time, this inevitably causes a buildup of heat. A warming of even a few degrees, occurring over the whole globe. can make an enormous difference. For example, the average temperature of the Earth at the coldest point during the last great ice age was only 4° to 8° F colder than the temperature today! That slight difference caused glaciers to cover nearly 1/3 of the Earth's landscape.

Several years ago, curious about the feel of an ice age, I decided to study the spot where I lived, a small house near downtown Minneapolis. The house is surrounded by tall trees, with balmy summers, squirrels, and bumper crops of grain that extend for 300 miles in every direction. I tried to imagine what that spot looked like 20,000 years ago at the peak of the last Ice Age (when the average temperature was roughly 5° F cooler than today). In a moment of daring, I imagined that the ice was maybe 100 feet deep on that spot. Later I studied the maps of the glaciers during the Ice Age, and I found that the ice had been one mile deep over that spot during the Ice Age.

James Lovelock, creator of the Gaia Hypothesis, says that the world warmed from Ice Age temperatures to balmy landscapes as carbon dioxide levels increased. Atmospheric carbon dioxide rose from 180 parts per million (ppm) during the Ice Age to 280 ppm just before the industrial revolution. Ten years from now, if we continue burning coal and oil, we will have put another 100 ppm of carbon dioxide and carbon dioxide equivalents into the air. As a result, climate scientists predict a 4° to 8° F average rise in temperature over the next years. We are creating a new Hot Age.

What will the Hot Age be like? We don't know for sure, but with computers we can estimate that a hotter global climate will show much hotter summers and drier soils in the centers of the continents. Weather everywhere is expected to be less predictable. This is likely to mean frequent droughts in the central parts of the continents: the American Breadbasket, the Russian agricultural heartland, and the major food-producing areas of China, India, and South America. Where droughts do not happen, unpredictable weather may well lead to frequent crop failures. One of the most certain impacts of warming is that the sea level will rise by at least two feet in the next 100 years, drowning low coastal cities, whole island nations, and the food-producing deltas of Egypt, Louisiana, and Bangladesh. During these same warming decades, the human population will be pushing its limits, perhaps doubling in size to ten billion. Thus. it seems that massive, unrelenting famine will take place on most of the world's continents.

Even a realistic optimist's scenario is not pretty. The pessimist's is bad beyond imagination. The human population could be reduced to a fraction of our present size, living on mountains along the new coastlines where the rains will still fall but the floods won't be so destructive. Ecosystems everywhere are likely to unravel, unable to adapt to the speed with which the Hot Age comes. As species most vulnerable to heat, drought, and blindness from UV-B radiation go extinct, the links that hold the natural systems together will give way.

With Tolstoy, we ask, "What then shall we do?" We have to work to reduce the world's carbon dioxide and CFC emissions. It's as simple as that. The technologies are ready, and the expense is not exorbitant. How this can be done is the subject of another essay.

Tyrone Cashman is a practicing Buddhist. an expert in alternative energy technologies. a philosopher. and a social activist who lives in the San Francisco Bay Area.