ou know something really serious is afoot when Wall Street analysts begin to factor greenhouse gas emissions into their assessment of long-term corporate risk. The reason, in a word, is science.
It's hard to keep up. Leading journals such as Science and Nature write new chapters in our understanding of global warming almost weekly. This often is arcane stuff, and the politicians and corporate executives don't actually read it. Instead, the most urgent parts land on their desks in the form of easily digestible summaries, accompanied by simple recommendations for action. In essence, that's what the Australian writer Tim Flannery sets out to do for the rest of us.
Flannery is a devotee of the Gaia hypothesis -- the idea, coined by the British scholar-scientist James Lovelock and named for the ancient Greek earth goddess, that the planet functions as a single, integrated, self-regulating organism. As Flannery notes acerbically, there's no longer any debate among legitimate scientists about whether the planet's regulatory mechanisms are under intense stress; disputes now involve only the scale and speed of the catastrophe. Will the Gulf Stream slow or shut down altogether? If we double the level of carbon dioxide in the atmosphere, will the increase in global temperatures be 9 degrees Fahrenheit or merely 4? Is there still a chance to save the polar ice caps, or have we already "tripped the switch" that will eventually lead to an ice-free world -- and to a 220-foot rise in ocean levels?
These are huge questions, the kind that can easily induce a sense of paralysis. But Flannery has a rare gift for bringing the macro down to the micro. The author is a well-known mammalogist and paleontologist, so it's not surprising that many of his most compelling passages concern the extinction of particular species. Flannery sees nothing abstract in phenomena like melting ice caps and bleaching coral reefs; whole magical worlds are unraveling here, an infinite spectrum of colors fading to a featureless blur of gray. When he describes the cascade of effects that result from marginal changes in temperature or precipitation, he drives your heart into your throat. It's hard not to be moved, for instance, by the image of Finnish reindeer scrabbling desperately at the ground to find life-sustaining lichens that have been iced over by abnormal autumn rains.
Flannery can also jolt you into understanding the significance of the humblest of critters. It matters enormously, for example, that Antarctic krill are being supplanted by gelatinous creatures called salps. Here's the causal chain: The loss of sea ice means a decline in the microscopic plankton on which krill feed, so krill populations plummet. In move the salps, which don't require anywhere near as much plankton. But the salps are so devoid of nutrients that they offer no sustenance to marine mammals and birds. Let's be honest, now: How many of us had even heard of salps?
In the struggle for survival, not all the competitors are created equal -- and that applies to human society just as much as to krill. Surprisingly little has been written on the relationships among global warming, social conflict, and inequality, but Flannery begins to fill the gap. The Darfur genocide, he argues, is essentially a function of climate change, as the desiccating desert land in western Sudan drives nomadic herders into areas of sedentary agriculture and into conflict with farmers for scarce resources. But Western urban societies, with their inherent tension between material needs and locally available resources, may also be at grave risk. Not all cities will survive, Flannery warns: Perth, in Western Australia (the country's fourth-largest city), with diminishing rainfall and far removed from alternative water supplies, may already be doomed. For similar reasons, certain cities in the American Southwest -- think Las Vegas or even Los Angeles -- may be hard to sustain indefinitely. Even worse, he implies, we may callously shrug off such losses as the cost of doing business in a warming world. It's sobering, of course, to think of the possible abandonment of the poorer sections of New Orleans in this light.
It has to be said that Flannery's galloping, protean intelligence sometimes gallops just a bit too fast for its own good, particularly where the discussion of remedies is concerned. Ethanol in all its forms (from corn, from sugar, and from crop residues and other "cellulosic" sources such as switchgrass, which even President Bush noted for its energy potential in his State of the Union address) is picked up and tossed aside in a paragraph. Yet such
fuels promise to add a new element to the energy mix -- and a renewable one at that. Similarly, his dismissive treatment of technologies such as carbon sequestration seems to be motivated in part by an animus against anything that emanates from the corporate imagination. That's too bad, since recent developments at General Electric, Duke Energy, and the like show that corporate innovation must inescapably be part of the solution.
But that's a quibble. When you're writing popular science from soup to nuts, some courses are bound to be less nutritious than others. No book on global warming is ever going to be definitive -- our understanding of the science is advancing too fast. But Flannery's should have a longer shelf life than most, and deservedly so.
-- George Black