The details of global warming, and the issue of man’s contribution to it, are not only controversial, but also hellishly complicated. On the level of public understanding, it would seem otherwise. Sunlight enters our atmosphere, and a portion of it is trapped by greenhouse gases, preventing it from radiating back into space. A network of sensors exists around the globe, taking measurements of carbon dioxide, water vapor, methane, chlorofluorocarbons, and other trace gases. When the measurements are combined together, a clear pattern of warming is evident, and the warming trend seems to be accelerating over the last century and a half, the period in which humans have increasingly relied upon fossil fuels for their energy needs and population growth.
Much of the global warming debate occurred within the rarefied air of the climate science community, and only became a hot political football during the last fifteen years, a period that marked the ascendancy of Al Gore as the first prominent politician who warned of dire consequences for the planet as a whole unless humans changed their energy-consuming habits. It is surely no coincidence that these fifteen years included ten of the hottest average years in the historical record, and featured a bewildering array of extreme weather events from destructive hurricanes and cyclones to anomalous tornadoes occurring in places they never had been seen before.
The debate moved from the halls of academe and entered into the popular culture with the disaster movie The Day After Tomorrow and with publication of speculative fiction like Kim Stanley Robinson’s global warming trilogy (Forty Signs of Rain, Fifty Degrees Below, and Sixty Days and Counting) and Michael Crichton’s contrarian novel State of Fear. A dull and obscure debate between specialists had become a moral issue about the fate of the planet, and two distinct and opposing points of view emerged, the true believers (in anthropogenic global warming) and the skeptics.
Chris Mooney’s book, which carries the subtitle “Hurricanes, Politics, and the Battle over Global Warming,” delves into this debate and describes the scientific reasoning of both sides. He focuses on two protagonists, hurricane forecaster William Gray of Colorado State and climate modeler Kerry Emanuel of MIT. Gray believes that the signs of global warming are part of the natural variability that our atmosphere undergoes, and bristles when journalists presume that any one meteorological event, like a strong hurricane, is caused by global warming. He comes from a line of empirical scientists who believe in following where the data leads. By immersing himself in the minutiae of weather measurements for decades, he has developed a finely-honed physical intuition that led him to become America’s top hurricane prediction expert. As a young scientist, he had flown into the eye of Atlantic hurricanes and pioneered techniques for extracting difficult-to-get measurements that would become the basis of his annual forecasts. For years, his record was exemplary, and he looked askance at a younger generation of climate scientists who used the number-crunching power of computers to simulate climate and weather events in their own virtual world. When these young Turks began speculating that hurricane frequency and intensity might have been affected by warming of the atmosphere, Gray went on the attack, becoming one of the leading contrarians to the new global warming orthodoxy, a scientist who openly ridiculed their methods and assumptions, and a rare skeptic who seemingly had no financial interest in this debate (Many of the other skeptics are scientists in the employ of the oil companies or their affiliated think tanks, and they play a very different game, one more akin to what lawyers do when they purposely delay and obfuscate so as to avoid regulatory pressures or mandatory changes in the way clients operate their businesses).
In the Eighties, Kerry Emanuel would have agreed with Bill Gray that it was impossible to assign causality for any one hurricane to such a complex phenomena as global warming. But Emanuel was a climate modeler, and General Circulation Models (GCMs) kept improving as supercomputer powers increased and the number of data points became larger and larger. Satellites could now sense sea surface temperatures, thermal expansion of the ocean, and the genesis of Atlantic hurricanes in unusual wind patterns emanating from the West Coast of Africa. The GCMs suggested that hurricane frequency and intensity would be diminished in years when El Nino was present in the western Pacific, and this proved to be the case. Most meteorologists agreed that the energy that drives hurricanes comes from warmer sea surface temperatures, and by the mid-Nineties, modelers like Emanuel and NASA’s James Hansen became convinced that these warmer sea surface temperatures were the result of not only atmospheric warming, but warming that was at least partially induced by human industrial and agricultural activities.
The turning point for the public was probably the devastation left behind by Hurricane Katrina (and later that same summer, by Rita) in 2005. New Orleans and the Gulf Coast were left in shambles by Katrina, and Hurricane Rita might have done the same to Houston had it not veered off its original course just as it was making landfall. Emanuel published papers that increasingly linked these anomalous weather events to the warming trend, while Gray’s predictions diminished in accuracy. Gray, now past retirement age with nothing to lose but his dignity, became more and more strident in his denunciation of the “equation pushers” and became something of a national celebrity (as did Emanuel) when television journalists hewed to their time-tested rule of “balancing the opposing viewpoints.”
Mooney is at his best when he shows how the hot lights of politics interfere with the practice of science, a phenomenon he had demonstrated earlier with his first book, The Republican War on Science. He is careful to be even-handed in this book, never holding Gray up for ridicule, but it is obvious that he is a believer in human-caused warming and that he worries that our convoluted political system, dominated by short-term, election year thinking, may not be up to the task of making the hard choices required to mitigate this problem. Mooney notes in his Prologue that he is from New Orleans, and he writes with an awareness that the Crescent City of his youth is no more. The story he tells is larger than an academic rivalry between two men, more fully nuanced than this brief review. As Mooney says, “Scientists, like hurricanes, do extraordinary things at high wind speeds.”
Reviews by Dean Rink
Dialogue on favorite books with Deane Rink before and during his latest trek to Antarctica, with a note from Bill Ransom and a digression about Frank Herbert (a.k.a Bookbabble 101) -- a very long and rapidly growing document: