I just finished Storm World, Chris Mooney’s in-depth reporting on the science and politics of the poorly understood link between hurricanes and global warming.
The topic is appealing, both because hurricanes have such a terrifying grip on the popular imagination and because the attendant controversy is in its own way a sort of perfect storm of media, politics and science.
We often refer casually to the scientific “consensus” on climate change. The consensus is real, but it doesn’t extend to all aspects of the climate system. One of the places where it frays most noticeably is around the matter of storms. It’s pretty clear that climate change will affect hurricanes somehow, but exactly how is an open question.
There are numerous theoretical reasons why we should expect to see a rise in the severity and possibly also the frequency of storms as the globe gets hotter. Hurricanes are a form of heat engine, fueled by the warmth of the ocean. It doesn’t take a huge leap of logic to see that global warming could have implications for the strength of future hurricanes. And indeed, that’s what a variety of computer models show. With increasing concentrations of CO2 in the atmosphere and a corresponding rise in ocean temperatures, most models show a clear uptick in the strength of hurricanes.
Nature itself has also been stoking the controversy, serving up year after year of record-breaking storms. Katrina was the most spectacular in terms of devastation, but certainly not in terms of strength. Just a few months after Katrina, Hurricane Wilma became the strongest storm ever recorded in the Atlantic basin, shattering records and devastating parts of Florida.
But individual data points don’t prove anything about trends or causes, and many meteorologists are unimpressed by the computer models. Mooney’s book traces the debate to a methodological split that dates back well over a hundred years. To oversimplify, there are two types of weathermen: empiricists and theorists.
The empiricists put their faith in the data, searching for patterns in mountains of measurements and attempting to tease out relationships that can be used to predict and explain. Theorists, on the other hand, are more interested in understanding why the climate behaves as it does. They are fond of mathematical models, and these days the primary tool at their disposal is the supercomputer, which can be used to run gigantic simulations of the entire climate system, again and again and again, under different conditions.
The empiricists point out, correctly, that the models operate on a scale that is awfully crude compared to the size of most hurricanes. They also point out, correctly, that we simply don’t know what makes hurricanes form, so any suggestion that we can accurately model the process is premature. Finally, given the inherent variability and relative rarity of hurricanes — about 80 per year — it will take decades to establish any sort of true statistical link between hurricanes and global warming.
All of this may be true, but in the politicized atmosphere in which the debate has played out, some empiricists have also clearly overplayed their hand, not just pointing out the uncertainty of the link, but actively denying that such a link exists. The most famous among them, legendary hurricane-researcher-turned-climate-skeptic Bill Gray, denies the existence of global warming entirely.
Mooney is most interesting when he explores the personalities of the people involved in the debate (which is a tiny bit ironic, given that one of the book’s themes is the media’s unfortunate tendency to focus more on personality than science). In Mooney’s telling, Gray is funny, gregarious, ferociously opinionated, and something of a jerk. He also comes across as a bit of a sad figure, someone whose obstinacy threatens to turn his distinguished career into a punch line.
Still, there are no villains and ultimately few easy conclusions in this solidly researched book, other than the frightening and obvious lesson that our current efforts at hurricane preparedness are woefully inadequate. It is not light reading — you really do have to be interested in the science of weather to get into this book — but if you want a case study on what it’s like to operate at the forefront of science under a media spotlight, I recommend picking it up.