Storm World: Hurricanes, Politics, and the Battle Over Global Warming
by Chris Mooney
Harcourt: 2007, 400 pages.
Buy now! (Amazon)
At 2:09 am on September 13, 2007, Hurricane Humberto made landfall just east of Galveston, Texas–still the site of the deadliest natural disaster in US history, the Galveston Hurricane of 1900. With maximum sustained winds of 85 mph, though, Hurricane Humberto was just a Category 1 storm (the weakest category on the Saffir-Simpson Scale). While it was the first hurricane to make landfall in the US since the record-breaking and devastating 2005 hurricane season, Hurricane Humberto was otherwise unexceptional.
Or, it would have been if it hadn’t been just a weak tropical depression only 16 hours before landfall.
Forecaster James Franklin of the National Hurricane Center put it bluntly:
BASED ON OPERATIONAL ESTIMATES…HUMBERTO STRENGTHENED FROM A 30 KT (35 mph) DEPRESSION AT 15Z (10 am) YESTERDAY TO A 75 KT (85 mph) HURRICANE AT 09Z (4 am) THIS MORNING…AN INCREASE OF 45 KT (50 mph) IN 18 HOURS. TO PUT THIS DEVELOPMENT IN PERSPECTIVE…NO TROPICAL CYCLONE IN THE HISTORICAL RECORD HAS EVER REACHED THIS INTENSITY AT A FASTER RATE NEAR LANDFALL.
(Parenthetical additions come from a posting by meteorologist Travis Herzog.)
The last sentence of Franklin’s dispatch, though, was the most poignant:
IT WOULD BE NICE TO KNOW…SOMEDAY…WHY THIS HAPPENED.
It is this type of question, in fact, that Chris Mooney explores in his new book Storm World. Although Mooney’s quest was spurred primarily by 2005’s Hurricane Katrina (which is no surprise as Mooney is a New Orleans native), these are only two of a host of recent events that beg the following questions: why are we suddenly seeing an increase in both the number and intensity of Atlantic hurricanes, what does this trend mean for our future, and, most importantly, is this trend linked to global warming?
In addressing these questions, Mooney takes the reader on a journey across the US (and the world), back in time to the early days of hurricane science, and into the heart of deadly storms whose intensities are only matched by the raucous political debate surrounding global warming. Mooney has already proven himself adept at addressing such complex and controversial political subjects as the author of the bestselling book The Republican War on Science, as the Washington correspondent for Seed magazine, and as a blogger at The Intersection. In this case, Mooney reveals an issue that is also controversial at the scientific level… although not as controversial as one might initially think.
Here are the facts. Firstly, 2005 was a record-breaking year and the most active Atlantic hurricane season ever observed. There were 28 named storms. Fifteen of these became hurricanes, and four became Category 5 hurricanes. All of these numbers broke previous records. The infamous Hurricane Katrina was the costliest on record, and Wilma was the strongest. The final storm of the season, Tropical Storm Zeta, even persisted into January 2006. Three of the six known most intense hurricanes formed that year.
Intuitively, one would expect an increase in average sea surface temperatures to increase the number and/or intensity of hurricanes. Mechanically, a hurricane is in a sense just a glorified heat engine. This is of course why hurricanes form almost exclusively in late summer and fall, when ocean surface temperatures are at their highest. It’s not much of a stretch to assume that hotter temperatures equal more or stronger hurricanes. Hurricane science is, not surprisingly, much more complicated than this, and hurricane formation and strength are based on many other factors, particularly vertical wind shear. However, modeling experiments predict an increase in average hurricane strength with increasing temperatures, and the actual increase in hurricane intensity already observed actually outpaces the modeling studies. On top of this, there is also evidence for an increase in frequency of hurricanes with rising temperature in the Atlantic Ocean.
In recounting all of this, Mooney maintains his objectivity masterfully. He is certainly no alarmist, although he doesn’t have to be. He explores all sides of this complex issue, and he introduces a wide array of interesting characters involved in the hurricane/global warming debate. Most notably, this includes the almost inordinate amount of time he spends with the charismatic hurricane scientist William Gray, an outspoken critic of global warming. Gray is known for his important contributions to hurricane forecasting, but he has more recently become known for his entertainingly wild presentations “debunking” global warming. Mooney spends quite a bit of time with him, and his students. Despite this, the facts of the case–the undeniable progress of global warming and its potential effects on hurricanes–eventually shine through.
In the process, Mooney sheds light on an interesting and deep-seated aspect of the debate between the camp that believes that global warming has and/or will increase hurricane activity (often climate scientists) and the camp that doesn’t (often practicing meteorologists). He traces this division back to the fascinating controversy that spurred the beginnings of hurricane science itself: the American Storm Controversy. In 1831, William Redfield began publishing papers making the case that hurricanes (and other storms) are characterized primarily by their rotation. An inductivist to the core, he relied strictly on the data that he and his colleagues observed directly, with little theoretical basis. In the 1930s, though, theorist James Pollard Espy began publicizing his own convection theory of storms. In his (largely correct) view, Espy postulated that storms are driven primarily by thermodynamics, through the rise of warm, moisture-laden air and its subsequent condensation. However, he deduced (incorrectly) from his theory that storm winds could only flow directly inward toward the storm center. Although we know today that Redfield and Espy were both partially correct, at the time they viewed their ideas as irreconcilable. Similarly, today’s controversy between the climate modelers and the on-the-ground meteorologists is largely a philosophical debate between the merits of induction versus deduction.
So, it should be no surprise, then, that Gray and many other meteorologists–scientists charged with the very difficult task of understanding and predicting an almost unimaginably complex phenomenon, the weather–are skeptical about the applications of climate science to their field. They deal day to day with enormous amounts of uncertainty. To them, the idea that other scientists can draw sweeping and far-reaching conclusions about the warming of the globe and how it will affect the very weather systems that these meteorologists study is improbable, misguided, and even heretical.
Therefore, I understand where Gray is coming from when he so vehemently challenges not only the idea that global warming has and will intensify hurricanes but also the fact that global warming is a human-generated process already taking place. I understand, but I disagree. Global warming is a very real phenomenon, one that a whole host of qualified scientists are currently studying and one that these scientists have already demonstrated is progressing at an alarming rate.
Just like the daily weather, the future of global climate change is uncertain. The optimistic spin on this is that it’s uncertain in that we have the opportunity to act now to stop it in its track, but the real uncertainty comes from the scientific process itself. Due to imperfect and incomplete information–the uncertainty that scientists of all types are accustomed to working with–we don’t know exactly how much the Earth is going to warm in the future, and we don’t know exactly what effect this warming will have on weather patterns. But, we have a pretty good idea. Over the last hundred years, the Earth’s surface has warmed by about 0.75°C, and depending on future global carbon dioxide emission rates, the increase over the next hundred years is likely to be 1.1°C to 6.4°C. Unfortunately, global warming denialists grab onto this uncertainty to challenge the very existence of global warming itself. I don’t mean to downplay this uncertainty–and the case regarding the link between global warming and hurricane activity is far from closed–but this uncertainty is all too often exaggerated. The denialist position is scientifically indefensible. Global warming is real: the scientific uncertainty is in the details.
Likewise, the exact effects of future global warming are not explicitly known. Still, without a doubt, global warming will cause an increase in sea level. Over the next hundred years, this increase is predicted to be 0.18-0.59 m (roughly a half a foot to two feet). The truly disturbing aspect of global warming, though, is how it could affect complex climate and weather patterns in somewhat unpredictable ways, especially in the way that small changes in temperature could be amplified into much larger changes in weather. Regardless, if global warming does increase the number and intensity of Atlantic hurricanes, as it may be doing already, the implications for coastal communities are grave (especially when rising sea levels are taken into account). The outcome will be incredibly expensive and possibly quite deadly.
Because of this, Mooney’s book does an important service by publicizing this threat. And, he manages to do it in a nuanced and scientifically accurate way. For this I applaud him, and I would highly recommend reading Storm World. However, that’s not what I really enjoyed about this book.
I’ll confess that since a young age I have been very interested (and at times obsessed) with the weather–storms in particular. This probably comes from growing up in north central Texas, at the southern tip of Tornado Alley. As a youngster, I couldn’t help but wonder what caused a lazy Texas summer afternoon to erupt in tumultuous thunderheads–seemingly out of nowhere–only to unleash their fury on the unsuspecting population below. And, even more interestingly, how could meteorologists predict such an uncertain future event? This led to hours perusing the public library, watching The Weather Channel, observing huge thunderheads roll into town, and eventually creating a middle school science fair project on the subject. Although my fascination with storms was eventually eclipsed by my interests in chemistry and biology, I still find the phenomena alluring.
Therefore, for me at least, reading Storm World was a real treat in that I had a reasonable excuse to delve once again into this childhood obsession of mine in a book full of science, history, and controversy. In addition, Mooney craftily weaves into this meteorological tale topics as disparate as climatology, politics, and even philosophy of science. And, he makes it all relevant.
I suppose, however, that what pulled me into this book was rather esoteric. I don’t think for a minute that this was Mooney’s purpose, because at the most fundamental level Storm World is a cautionary tale. It’s a warning against scientists becoming too stuck in their ways, against scientific controversies being taken out of context in the media, and, most poignantly, a warning about the world we may be forced to live in if global warming continues to spiral out of control.
It’s scary stuff, so we ought to pay attention.