We’ve all read the hysterical headlines and the apocalyptic predictions of death, mayhem, and hell on earth that global climate change will cause as it increases the number, intensity, and severity of hurricanes around the globe.
National Geographic writers eagerly parroted warnings that,
More heat could “generate more storms and more intense hurricanes” (and) … a new study in the journal Nature found that hurricanes and typhoons have become stronger and longer-lasting over the past 30 years. These upswings correlate with a rise in sea surface temperatures.
The duration and strength of hurricanes have increased by about 50 percent over the last three decades, according to study author Kerry Emanuel, a professor of atmospheric science at the Massachusetts Institute of Technology in Cambridge.
From the RealClimate blog — which bills itself as a source of “climate science from climate scientists” — we are instructed that in the real world there is “no way to prove” that climate change will impact on either the frequency or severity of hurricanes. We are also told that,
due to the semi-random nature of weather, it is wrong to blame any one event such as Katrina specifically on global warming
All that aside, the climate scientists then move on to show how it is possible to employ arcane and confusing statistical analyses and complex computer modeling to move beyond the real world and actual research findings. Using those statistics and climate models, scientists can input data that helps suggest that climate change will strengthen already forming hurricanes.
Yet this is not the right way to frame the question. As we have also pointed out in previous posts, we can indeed draw some important conclusions about the links between hurricane activity and global warming in a statistical sense. The situation is analogous to rolling loaded dice: one could, if one was so inclined, construct a set of dice where sixes occur twice as often as normal. But if you were to roll a six using these dice, you could not blame it specifically on the fact that the dice had been loaded. Half of the sixes would have occurred anyway, even with normal dice. Loading the dice simply doubled the odds. In the same manner, while we cannot draw firm conclusions about one single hurricane, we can draw some conclusions about hurricanes more generally. In particular, the available scientific evidence indicates that it is likely that global warming will make – and possibly already is making – those hurricanes that form more destructive than they otherwise would have been. …
Hurricane forecast models (the same ones that were used to predict Katrina’s path) indicate a tendency for more intense (but not overall more frequent) hurricanes when they are run for climate change scenarios (Fig. 1).
In the particular simulation shown above, the frequency of the strongest (category 5) hurricanes roughly triples in the anthropogenic climate change scenario relative to the control. This suggests that hurricanes may indeed become more destructive (1) as tropical SSTs warm due to anthropogenic impacts.
Very interesting.
Moving forward, we can also find the hard-working journalists at Time magazine working to build fear of the next big hurricane that will inevitably strike the Gulf Coast. They instruct us that the people of New Orleans are,
mostly thinking about the savage rains and 140 mph winds that have driven them from their homes. But it’s that meteorological arcana that’s made such a mess of the bayou, and to hear a lot of people tell it, we have only ourselves—and our global-warming ways—to blame. …
So is global warming making the problem worse? Superficially, the numbers say yes—or at least they seem to if you live in the U.S. From 1995 to 1999, a record 33 hurricanes struck the Atlantic basin, and that doesn’t include 1992′s horrific Hurricane Andrew, which clawed its way across south Florida in 1992, causing $27 billion dollars worth of damage. More-frequent hurricanes are part of most global warming models, and as mean temperatures rise worldwide, it’s hard not to make a connection between the two. …
One especially sobering study from the Massachusetts Institute of Technology found that hurricane wind speeds have increased about 50% in the past 50 years. And since warm oceans are such a critical ingredient in hurricane formation, anything that gets the water warming more could get the storms growing worse. Global warming, in theory at least, would be more than sufficient to do that. While the people of New Orleans may not see another hurricane for years, the next one they do see could make even Katrina look mild.
Spooky, isn’t it? But that’s not all. The Pew Center on Global Climate Change continues by invoking the name and research findings of the all-knowing, all-seeing IPCC
Intensity: According to the 2007 Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4), it is “more likely than not” (better than even odds) that there is a human contribution to the observed trend of hurricane intensification since the 1970s. In the future, “it is likely [better than 2 to 1 odds] that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical [sea surface temperatures].”
Frequency: According to the IPCC-AR4, on a global scale, “[t]here is no clear trend in the annual numbers [i.e. frequency] of tropical cyclones.” As discussed above, however, the frequency of tropical storms has increased dramatically in the North Atlantic. Reasons for this increase are currently subject to intense debate among climate scientists. At least two recent peer-reviewed scientific studies indicate a significant statistical link between the increased frequency and global warming, but research to identify a mechanism explaining this link is ongoing.
Clearly, the links are there. Too strong to deny and too numerous to question. Right? You’re continued use of the internal combustion engine, your “addiction” to oil, your new Blackberry, and your general western, imperialist brand of capitalist over-consumption ARE causing more and stronger tropical storms and hurricanes. Admit it and be frightened, very very frightened.
Or not. You see, all those reports and links and statistical games and pretend worlds that we build in our climate models might just be wrong. Or so says new research that has been published in Nature magazine.
A new method for modelling hurricanes suggests that a warmer climate might not increase storm intensity as much as was previously believed.
The results came as a surprise to lead author Kerry Emanuel, a hurricane expert at the Massachusetts Institute of Technology in Cambridge, who had previously argued that global warming was behind an estimated 75% increase in category 4 and 5 hurricanes since 1970. …
He suggests one of two explanations: either the recent increase is not due primarily to global warming, or the current generation of global climate models is not effectively capturing the effects of global warming in the future. Others say that it could be a combination of the two.
Stormy history“Those are two interpretations, and they could both be true to a certain degree,” says Gabriel Vecchi, an oceanographer with the National Oceanic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey. “I think their paper really highlights the subtlety of the question: depending on which models they use, depending on which metrics they use, they can get different answers.”
Did you read that? Read it again
“I think their paper really highlights the subtlety of the question: depending on which models they use, depending on which metrics they use, they can get different answers.”
That’s the climate scientist’s way to say the well-known computer and modeling phrase, “garbage in … garbage out.” In other words, they can tweak their modeling findings to suit their world view. If they happen to believe in anthropogenic global climate change (or need to support that theory as a means of ensuring a continued stream of research dollars), they can fiddle around in the guts of their models (subtly of course) and — SHAZAM!!!! — the models show that anthropogenic global climate change is happening and is changing the frequency and severity of tropical storms. If, however, they need to try and come up with a reason for why their dire predictions of massively destructive hurricanes throughout the 2006 and 2007 hurricane season never appeared, they just
spontaneously ‘seeds’ storms within global climate models, rather than initiating small storms in certain areas on the basis of historical observations.
Then they press < Enter > on the big ol’ computer model and … chugga chugga chugga … ding! Out pops the answer.
This method was able to reproduce the increase in major storms seen in recent decades fairly well. Projecting forwards by almost two centuries, to the period 2181–2200, the model suggests that, overall, global storm frequency decreases. Storm intensity increases modestly in certain regions, including the northern Atlantic Ocean.
So now some in the scientific fraternity appear to have moved beyond the notion that,
“more likely than not” (better than even odds) that there is a human contribution to the observed trend of hurricane intensification since the 1970s.
to admitting that,
In particular, climate models systematically fail to reproduce the kinds of major storm observed in the tropics owing to the way they handle heat convection, he says. “Climate models have certain inherent flaws that may prejudice the results somewhat, and my suggestion is that they may prejudice them in the direction of fewer major storms.”
In the mean-time, you should keep your heartbeat and stress levels elevated and continue to reassure yourself that there is a large, potentially devastating (something) that is waiting out there, ready to pounce and inflict grievous damage on you, your family, your belongings, and everything you hold near and dear. You should also remember that whatever that great and terrible something is, it’s your fault and most likely due to the fact that you bought your kid the XBOX 360 for Christmas last year.
