Eye of Hurricane Isabel, courtesy of NASA
“Hurakan” (also Huracan; Jun Raqan) is the name of a Maya storm/Creator god that is the probable origin of the English word “hurricane”. In the Popol Vuh, the first men that populated the Earth (there existed an even earlier, failed attempt to create men out of mud) were made of wood. Although they could speak and reproduce, and multiplied across the face of the Earth, they forgot their Creators and had no minds or souls. Hurakan and the other Creator gods exacted retribution on them, sending a great deluge and other punishments. Not only did the beasts wild and domestic turn on these first men for their mistreatment of them, so too did their own tools and trappings of civilization.
Atlantic tropical cyclones comprise only a fraction of global storms, and land-falling Atlantic hurricanes make up an even smaller number. Since the record 2004 and 2005 Atlantic hurricane seasons and the Katrina disaster however, Atlantic hurricanes have received an amount of press greatly disproportionate to their global number- often in the context of anthropogenic warming.
A new study (full study PDF) has been published online Sunday in Nature: Geoscience, led by Thomas Knutson dealing with this very topic. Knutson et al. seek to use a regional model (RCM) to analyze the effect of future anthropogenic warming on Atlantic tropical cyclone frequency and intensity, albeit with notable caveats. The popular press is mangling it as expected. Knutson 2008 and the accompanying reaction in the press share a lot of similarity to a recent study lead by Kerry Emanuel, as RealClimate notes.
The reaction fits the model of the “windshield wiper effect”, as described by* Andy Revkin (of Dot Earth)- where one study pushes the science and media coverage one way, another pushes it back. The Knutson et al. study seems to be generating a number of headlines where it is perceived to be “pushing back” against the assumption that storms and Atlantic hurricanes will increase not only in intensity, but in frequency as well. Of course, the current proto-consensus is more accurately described as that although overall cyclone frequency may decrease (perhaps overall, and likely in some regions), intensity will increase in the Atlantic cyclone basin and elsewhere. Others have and no doubt will do a far better job of noting why this study shouldn’t be taken as gospel, including the authors themselves, but this doesn’t seem to have stopped the media, and we can look forward to this being touted amongst the usual suspects as evidence against anthropogenic warming in general when it is obviously nothing of the sort. [The two most popular tacks seem to be that this study is ‘evidence’ that modeling is meaningless and that it is a CYA move of climatological revisionism as 2006 and 2007 have been relatively tame years compared to 2004 and 2005.]
Such crude regional projections, and short term forecasts like the similarly media-butchered Keenlyside 2008, are a logical and necessary evolution of climate science and modeling. And they should be welcomed as the aim of modeling moves from longterm projections of forced changes to GMST and precipitation towards shorter timescales and smaller areas of impact. It is important, as has been remarked upon in regards to Keenlyside 2008 (and Smith 2007 before it) that their limitations should be acknowledged and the media be dissuaded from treating each new study as thought it enjoys the same level of agreement and confidence as do the IPCC Assessment Reports.
To that end, it could be easy to fall into repeated betting as a means to set the media straight, but I think this is a losing proposition over time- even though I accept and see no problem with it being used to prove a point once in a while. Rather than treating the symptoms, the root problem needs to addressed. The media (with some notable, but sadly far too uncommon exceptions, such as Dot Earth), still retains a shockingly immature stance on climate science reporting. The illusion of disagreement on broad issues, the aforementioned “windshield wiper” effect, and the constant use of climate change as a story peg in a poorly explained manner have to be dealt with if an informed consumer-voter population base is to be achieved. As with so many subjects today, climate change is severely lacking proper nuance in the press, especially in regards to issues like hurricanes, and even more so when complicated by our bizarrely partisan views on global warming in America.
*I say ‘described’ rather than ‘coined by’ as it seems to be a modification of a metaphor told to Revkin by former director of the National Hurricane Center Max Mayfield in a 2004 article in the New York Times.
[UPDATE: Dot Earth has more. ]