Fear the Megafart
This book was published in England under the title, The Last Generation: How Nature Will Take Her Revenge for Climate Change. The titles’ differing emphases is fascinating. To me, the American title almost makes climate change sound alluring—“with speed and violence” sounds like Mel Kiper, Jr. describing a linebacker, plus there’s the odd blend of reason (scientists) with raw emotion (fear)—while the British version hearkens back to “Nature, red in tooth and claw.”
Pearce’s basic thesis is that climate science has evolved dramatically in the past two decades, stressing the complexity of weather, especially various feedback loops that retard or accelerate climate change. His differing titles point up the two related, but distinct, perspectives behind this thesis. The first perspective is that of straightforward reportage. It turns out that scientists are increasingly confident that Earth’s climate is not a stable system, given only to incremental changes. Instead, the system is prone to “drunken lurches”—periods in which the weather changes rapidly, and not just in geological terms. More than this, scientists are only now beginning to understand the complex interchanges between weather systems across different temporal perspectives. (To take just one example: In certain northern latitudes, planting trees now to soak up carbon would paradoxically *increase* warming tendencies that have already begun.)
The second perspective is closely aligned with James Lovelock’s theory of Gaia’s revenge. This argument starts from the premises of the first perspective: Earth’s climate is a dynamic, chaotic system. Like the first perspective, it also notes that virtually every system which we can measure now shows signs of stress, many of which are attributable to manmade warming. The argument then has to extrapolate a little beyond the science. Because some of the systems have never experienced such stress before, Pearce invites us to consider what will happen if everything goes wrong.
While this might sound like irresponsible alarmism, Pearce has good reasons for presenting this second perspective. The first is the historical record, especially as it has been supplemented by tropical, and not just polar, evidence. With Speed and Violence presents an array of examples of dramatic short-term changes in Earth’s weather, any of which would, at best, be economically disastrous, and, at worst, potentially threatening to civilization in its current form. Pearce’s favorite examples appear to be methane-related, in particular the so-called “megafart” some 55 million years ago. The second reason for Pearce’s apparent alarmism is the relationship between the historical record and observable processes in the present. It’s not just that the ice is receding everywhere. Potentially even more devastating is the melting of the permafrost around the Arctic. That’s not just a predicted outcome of global warming—it’s here now. And as the permafrost melts, more of the vegetation trapped within it will decay, releasing increasing amounts of methane into the air. The third reason Pearce engages in what we might call tactical alarmism is that catastrophic events—such as the rapid collapse of the western Antarctic ice shelf, or the apparent intensification of El Niño—have helped push the science along. In alarming times, being an alarmist makes you right, and especially over the past ten years or so, we have repeatedly broken thresholds for climate change more quickly than anyone anticipated. In fact, the historical record is no longer any guide, because it can’t account for the myriad assaults on the environment of the 20th and 21st centuries.
The dynamism of the global climate, and the statistical models required to interpret and model it, are so complex that it is almost impossible to speak definitively about causal mechanisms. Take Hurricane Katrina. On the one hand, one can’t really say that global warming caused the hurricane. There have been intense, devastating storms long before the current warming trend, and storms of Katrina’s magnitude, while unlikely, are not unheard of. On the other hand, 2005 was a year of freak storms in the Atlantic, with hurricanes in places they’d never been, and catastrophic rates of destruction. And Katrina did strengthen when it stalled in the Gulf of Mexico, where the water in August 2005 was the warmest it had ever been, 86 degrees (the threshold for hurricane pillars is 78 degrees F) “to a depth of some 300 feet” (“tens of yards” would have been enough for a minor hurricane. Stalling over the warm water recharged Katrina, making an already ominous storm a city-killer. Did warming cause Katrina? No way to know. Did it make a bad storm worse? According to Pearce, “with every year that passes, warm water is penetrating ever deeper into the world’s oceans. That is clearly tied to global warming. And it is setting up ideal conditions for more violent thunderstorms.”
Where With Speed and Violence excels is in showing how these complex, poorly understood systems seem to be teaming up. It’s not just that melting ice might raise the sea level, which would be bad. It’s also that it would add more freshwater to the sea at crucial “chimneys” in the ocean conveyer. Warmer water could melt methane clathrates under the ocean floor. There are implications for albedo, or the reflectivity of the earth’s surface. Warming is accelerated by stratospheric jets that, cooled by greenhouse gases, perversely drive polar winds to warm the land. Now, some of these could happen, or perhaps none of them. But Pearce’s point is that they turn out to reinforce each other in weird and surprising ways, suggesting that climate change will get nastier long before it gets better.
However, there is, I’m convinced, something awry in Pearce’s book. It’s not the science. Rather, it’s hard for me to imagine who will read this book in 2007 and have their mind changed. If you are the sort likely to read a book about the worsening prospects for climate change, then you probably already know, at least in broad outline, many of the threats With Speed and Violence details. If, however, you are skeptical about these claims, then I doubt you’ll be persuaded by Pearce’s tendency to concatenate chains of possible disasters. The result, then, is a book that reads oddly like environmental pornography: Its likeliest audience is readers who, fully cognizant of the gravity of our climactic predicament, desire further proof of our imminent destruction. There’s an odd jolt of thrilled recognition—oh, that’s what our death looks like in real-time!—as the evidence accumulates that we have already begun processes of warming and change that are not easily reversible.