高级英语第三课ShipsintheDesert.doc

Lesson 3 Ships in the Desert
AL Gore
1. I was standing in the sun on the hot steel deck of a fishing ship capable of processing a fifty-ton catch on a good day. But it wasn’t a good day. We were anchored in what used to be the most productive fishing site in all of central Asia, but as I looked out over the bow, the prospects of a good catch looked bleak. Where there should have been gentle blue-green waves lapping against the side of the ship, there was nothing but hot dry sand——as far as I could see in all directions. The other ships of the fleet were also at rest in the sand, scattered in the dunes that stretched all the way to the horizon. Ten years ago the Aral was the fourth-largest inland sea in the world, comparable to the largest of North America’s Great Lakes. Now it is disappearing because the water that used to feed it has been diverted in an ill-considered irrigation scheme to grow cotton in the desert. The new shoreline was almost forty kilometers across the sand from where the fishing fleet was now permanently docked. Meanwhile, in the nearby town of Muynak the people were still canning fish——brought not from the Aral Sea but shipped by rail through Siberia from the Pacific Ocean, more than a thousand miles away.
2. My search for the underlying causes of the environmental crisis has led me to travel around the world to examine and study many of these images of destruction. At the very bottom of the earth, high in the Trans-Antarctic Mountains, with the sun glaring at midnight through a hole in the sky, I stood in the unbelievable coldness and talked with a scientist in the late tall of 1988 about the tunnel he was digging through time. Slipping his parka back to reveal a badly burned face that was cracked and peeling, he pointed to the annual layers of ice in a core sample dug from the glacier on which we were standing. He moved his finger back in time to the ice of two decades ago. “Here’s where the U.S Congress passed the Clean Air Act,” he said. At the bottom of the world, two continents away from Washington, D.C., even a small reduction in one country's emissions had changed the amount of pollution found in the remotest end least accessible place on earth.
3. But the most significant change thus far in the earth’s atmosphere is the one that began with the industrial revolution early in the last century and has picked up speed ever since. Industry meant coal, and later oil, and we began to burn lots of it——bringing rising levels of carbon dioxide (CO2) , with its ability to trap more heat in the atmosphere and slowly warm the earth. Fewer than a hundred yards from the South Pole, upwind from the ice runway where the ski plane lands and keeps its engines running to prevent the metal parts from freeze-locking together, scientists monitor the air several times every day to chart the course of that inexorable change. During my visit, I watched one scientist draw the results of that day’s measurements, pushing the end of a steep line still higher on the graph. He told me how easy it is——there at the end of the earth——to see that this enormous change in the global atmosphere is still picking up speed.
4. Two and a half years later I slept under the midnight sun at the other end of our planet, in a small tent pitched on a twelve-toot-thick slab of ice floating in the frigid Arctic Ocean. After a hearty breakfast, my companions and I traveled by snowmobiles a few miles farther north to a rendezvous point where the ice was thinner——only three and a half feet thick——and a nuclear submarine hovered in the water below. After it crashed through the ice, took on its new passengers, and resub merged, I talked with scientists who were trying to measure more accurately the thickness of the polar ice cap, which many believe is thinning as a result of global warming. I had just negotiated an agreement between ice scientists and the U.S. Navy to secure the release of previously top secret data from submarine sonar tracks, data that could help them learn what is happening to the north polar cap. Now, I wanted to see the pole it-self, and some eight hours after we met the submarine, we were crashing through that ice, surfacing, and then I was standing in an eerily beautiful snowscape, windswept and sparkling white, with the horizon defined by little hummocks, or “pressure ridges” of ice that are pushed up like tiny mountain ranges when separate sheets collide. But here too, CO2, levels are rising just as rapidly, and ultimately temperature will rise with them——indeed, global warming is expected to push temperatures up much more rapidly in the polar regions than in the rest of the world. As the polar air warms, the ice here will thin; and since the polar cap plays such a crucial role in the world’s weather system, the consequences of a thinning cap could be disastrous.
5. Considering such scenarios is not a purely speculative exercise. Six months after I returned from the North Pole, a team of scientists reported dramatic changes in the pattern of ice distribution in the Arctic, and a second team reported a still controversial claim (which a variety of data now suggest) that, over all, the north polar cap has thinned by 2 percent in just the last decade. Moreover, scientists established several years ago that in many land areas north of the Arctic Circle, the spring snowmelt now comes earlier every year, and deep in the tundra below, the temperature of the earth is steadily rising.
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6. As it happens, some of the most disturbing images of environmental destruction can be found exactly halfway between the North and South poles——precisely at the equator in Brazil ——where billowing clouds of smoke regularly blacken the sky above the immense but now threatened Amazon rain forest. Acre by acre, the rain forest is being burned to create fast pasture for fast-food beef; as I learned when I went there in early 1989, the fires are set earlier and earlier in the dry season now, with more than one Tennessee’s worth of rain forest being slashed and burned each year. According to our guide, the biologist Tom Lovejoy, there are more different species of birds in each square mile of the Amazon than exist in all of North America——which means we are silencing thousands of songs we have never even heard.
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7. But one doesn't have to travel around the world to witness humankind’s assault on the earth. Images that signal the distress of our global environment are now commonly seen almost anywhere. On some nights, in high northern latitudes, the sky itself offers another ghostly image that signals the loss of ecological balance now in progress. If the sky is clear after sunset——and it you are watching from a place where pollution hasn't blotted out the night sky altogether——you can sometimes see a strange kind of cloud high in the sky. This “noctilucent cloud” occasionally appears when the earth is first cloaked in the evening darkness; shimmering above us with a translucent whiteness, these clouds seem quite unnatural. And they should: noctilucent clouds have begun to appear more often because of a huge buildup of methane gas in the atmosphere. (Also called natural gas, methane is released from landfills, from coal mines and rice paddies, from billions of termites that swarm through the freshly cut forestland, from the burning of biomass and from a variety of other human activities. ) Even though noctilucent clouds were sometimes seen in the past, all this extra methane carries more water vapor into the upper atmosphere, where it condenses at much higher altitudes to form more clouds that the sun’s rays still strike long after sunset has brought the beginning of night to the surface far beneath them.
8. What should we feel toward these ghosts in the sky? Simple wonder or the mix of emotions we feel at the zoo? Perhaps we should feel awe for our own power: just as men tear tusks from elephants’ heads in such quantity as to threaten the beast with extinction, we are ripping matter from its place in the earth in such volume as to upset the balance between daylight and darkness. In the process, we are once again adding to the threat of global warming, because methane has been one of the fastest-growing green-house gases, and is third only to carbon dioxide and water vapor in total volume, changing the chemistry of the upper atmosphere. But, without even considering that threat, shouldn’t it startle us that we have now put these clouds in the evening sky which glisten with a spectral light? Or have our eyes adjusted so completely to the bright lights of civilization that we can’t see these clouds for what they are——a physical manifestation of the violent collision between human civilization and the earth?
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9. Even though it is sometimes hard to see their meaning, we have by now all witnessed surprising experiences that signal the damage from our assault on the environment——whether it's the new frequency of days when the temperature exceeds 100 degrees, the new speed with which the sun burns our skin, or the new constancy of public debate over what to do with growing mountains of waste. But our response to these signals is puzzling. Why haven’t we launched a massive effort to save our environment? To come at the question another way: Why do some images startle us into immediate action and focus our attention or ways to respond effectively? And why do other images, though sometimes equally dramatic, produce instead a Kin. of paralysis, focusing our attention not on ways to respond but rather on some convenient, less painful distraction?
10. Still, there are so many distressing images of environmental destruction that sometimes it seems impossible to know how to absorb or comprehend them. Before considering the threats themselves, it may be helpful to classify them and thus begin to organize our thoughts and feelings so that we may be able to respond appropriately.
11. A useful system comes from the military, which frequently places a conflict in one of three different categories, according to the theater in which it takes place. There are “local” skirmishes, “regional” battles, and “strategic” conflicts. This third category is reserved for struggles that can threaten a nation’s survival and must be under stood in a global context.
12. Environmental threats can be considered in the same way. For example, most instances of water pollution, air pollution, and illegal waste dumping are essentially local in nature. Problems like acid rain, the contamination of underground aquifers, and large oil spills are fundamentally regional. In both of these categories, there may be so many similar instances of particular local and regional problems occurring simultaneously all over the world that the patter n appears to be global, but the problems themselves are still not truly strategic because the operation of the global environment is not affected and the survival of civilization is not at stake.
13. However, a new class of environmental problems does affect the global ecological system, and these threats are fundamentally strategic. The 600 percent increase in the amount of chlorine in the atmosphere during the last forty years has taken place not just in those countries producing the chlorofluorocarbons responsible but in the air above every country, above Antarctica, above the North Pole and the Pacific Ocean——all the way from the surface of the earth to the top of the sky. The increased levels of chlorine disrupt the global process by which the earth regulates the amount of ultraviolet radiation from the sun that is allowed through the atmosphere to the surface; and it we let chlorine levels continue to increase, the radiation levels will also increase——to the point that all animal and plant life will face a new threat to their survival.
14. Global warming is also a strategic threat. The concentration of carbon dioxide and other heat-absorbing molecules has increased by almost 25 per cent since World War II, posing a worldwide threat to the earth’s ability to regulate the amount of heat from the sun retained in the atmosphere. This increase in heat seriously threatens the global climate equilibrium that determines the pattern of winds, rainfall, surface temperatures, ocean currents, and sea level. These in turn determine the distribution of vegetative and animal life on land and sea and have a great effect on the location and pattern of human societies.
15. In other words, the entire relationship between humankind and the earth has been transformed because our civilization is suddenly capable of affecting the entire global environment, not just a particular area. All of us know that human civilization has usually had a large impact on the environment; to mention just one example, there is evidence that even in prehistoric times, vast areas were sometimes intentionally burned by people in their search for food. And in our own time we have reshaped a large part of the earth’s surface with concrete in our cities and carefully tended rice paddies, pastures, wheat fields, and other croplands in the countryside. But these changes, while sometimes appearing to be pervasive, have, until recently, been relatively trivial factors in the global ecological sys-tem. Indeed, until our lifetime, it was always safe to assume that nothing we did or could do would have any lasting effect on the global environment. But it is precisely that assumption which must now be discarded so that we can think strategically about our new relationship to the environment.
16. Human civilization is now the dominant cause of change in the global environment. Yet we resist this truth and find it hard to imagine that our effect on the earth must now be measured by the same yardstick used to calculate the strength of the moon’s pull on the oceans or the force of the wind against the mountains. And it we are now capable of changing something so basic as the relationship between the earth and the sun, surely we must acknowledge a new responsibility to use that power wisely and with appropriate restraint. So far, however, We seem oblivious of the fragility of the earth’s natural systems.
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17. This century has witnessed dramatic changes in two key factors that define the physical reality of our relationship to the earth: a sudden and startling surge in human population, with the addition of one China’s worth of people every ten years, and a sudden acceleration of the scientific and technological revolution, which has allowed an almost unimaginable magnification of our power to affect the world around us by burning, cutting, digging, moving, and transforming the physical matter that makes up the earth.
18. The surge in population is both a cause of the changed relationship and one of the clearest illustrations of how startling the change has been, especially when viewed in a historical context. From the emergence of modern humans 200,000 years ago until Julius Caesar’s