Dark green A scientist argues that the natural world isn't benevolent and sustaining: it's bent on self-destruction By Drake Bennett January 11, 2009 WHEN WE LOOK at nature, it has become commonplace to see a fastidiously self-regulating system at work: wildebeest trim the savannah grasses, lions cull the wildebeest herds, and vultures clean the bones of both. Forests take in the carbon dioxide we exhale, use it to grow, and replace it with oxygen. The planet even has a thermostat, the carbon cycle, which relies on the interplay of volcanoes, rain, sunlight, plants, and plankton to keep the earth's temperature in a range congenial to life. This idea of nature's harmonious balance has become not just the bedrock of environmental thought, but a driving force in policy and culture. It is the sentiment behind Henry David Thoreau's dictum, "In wildness is the preservation of the world." It lies behind last summer's animated blockbuster "Wall-E," in which a single surviving plant helps revive an earth smothered beneath the detritus of human overconsumption. It underlies environmental laws that try to minimize the damaging influence of humans on land and the atmosphere. In this line of thought, the workings of the natural world, honed over billions of years of evolution, have reached a dynamic equilibrium far more elegant - and ultimately durable - than the clumsy attempts humankind makes to alter or improve them. According to the paleontologist Peter Ward, however, nothing could be further from the truth. In his view, the earth's history makes clear that, left to run its course, life isn't naturally nourishing - it's poisonous. Rather than a supple system of checks and balances, he argues, the natural world is a doomsday device careening from one cataclysm to another. Long before humans came onto the scene, primitive life forms were busily trashing the planet, and on multiple occasions, Ward argues, they came close to rendering it lifeless. Around 3.7 billion years ago, they created a planet-girdling methane smog that threatened to extinguish every living thing; a little over a billion years later they pumped the atmosphere full of poison gas. (That gas, ironically, was oxygen, which later life forms adapted to use as fuel.) The story of life on earth, in Ward's reckoning, is a long series of suicide attempts. Four of the five major mass extinctions since the rise of animals, Ward says, were caused not by meteor impacts or volcanic eruptions, but by bacteria, and twice, he argues, the planet was transformed into a nearly total ball of ice thanks to the voracious appetites of plants. In other words, it's not just human beings, with our chemical spills, nuclear arsenals, and tailpipe emissions, who are a menace. The main threat to life is life itself. "Life is toxic," Ward says. "It's life that's causing all the damn problems." Ward holds the Gaia Hypothesis, and the thinking behind it, responsible for encouraging a set of fairy-tale assumptions about the earth, and he'd like his new book, due out this spring, to help puncture them. He hopes not only to shake the philosophical underpinnings of environmentalism, but to reshape our understanding of our relationship with nature, and of life's ultimate sustainability on this planet and beyond. (Brian Stauffer for The Boston Globe) Although Ward's ideas have yet to reach a broad audience, some scientists are welcoming his portrait of a constantly off-kilter earth as a corrective to the gauzier precepts that have cast their spells on environmental philosophy and policy. Others, however, describe his hypothesis as simply Gaia's dark twin, a model undermined by the same inclination to see one tendency as the whole story. Ward is open to the criticism that he's taken things too far; what's important, he believes, is weaning people from the idea that the earth works better without us. Even if Medea is an incomplete framework for viewing the natural world, it introduces a hardheadedness into environmental debates often driven by an unexamined idealism about Mother Nature. Ward himself believes that the only help for the planet over the long run is management by human beings - whether that means actively adjusting the chemical composition of the atmosphere or using giant satellites to modify the amount of sunlight that reaches us. As Ward sees it, the planet doesn't need our help destroying itself. It will do that automatically. It needs us to save it. For most of human history, it would have been alien to think of the planet as a "system" at all - the earth seemed an essentially infinite expanse of lands and seas that, depending on your theology, awaited human cultivation or demanded human deference. But with the Industrial Revolution it started to become clear that humans themselves were making changes with far-reaching, unintended, and destructive consequences, and over the 20th century an alternative understanding of the natural world began to take hold. This view saw the earth as a closed system with an inherent natural order, and pointed out the ways it broke down when we stressed it by pumping chemicals into the air or killing off animals that were vital links in food chains. By the late 1970s, when the British scientist James Lovelock proposed the Gaia Hypothesis, something that once might have seemed like science fiction - the notion that all living things on the planet were linked like the cells in a single body - seemed like a persuasive model. Lovelock was a serious scientist - a creation of his, the electron capture detector, was to prove instrumental in revealing the depletion of the ozone layer - and he had plenty of evidence for his theory. He pointed to the fact that, despite the wide variability of the sun's heat over the eons, microbes and plants have altered both the atmosphere and the ground to keep the temperature almost entirely within the narrow range in which terrestrial life thrives. For nearly as long, the amount of oxygen that plants and geological processes released into the atmosphere has remained at a point high enough to feed the metabolisms of quintillions of animals, but not so high that every forest was constantly going up in flames.Continued... More.... "The longevity of the biosphere can only be sustained through large-scale geoengineering," Ward argues. Without our firm hand, he believes, "the earth will go to hell in a handbasket," just as it has again and again in the past.Read more…
