Bad Timing for These Two Hurricane Experts

The 2005 Hurricane season was the most active and destructive in recorded history. The devastation from hurricanes like Katrina, Rita, and Wilma was powerful evidence that man-made global warming had triggered an onslaught of unforeseen consequences — at least, that was the way the media tended to portray it. Maybe I am wrong, but I think the current focus on global warming in this country would be much weaker had those hurricanes not hit landfall, or had they hit Mexico instead of the U.S.

The scientific community, however, never argued a strong link between global warming and hurricanes. At the Sixth International Workshop on Tropical Cyclones held by the World Meteorological Organization in November of 2006, the participants came to the following conclusions:

Consensus statements by the workshop participants

1. Though there is evidence both for and against the existence of a detectable anthropogenic signal in the tropical cyclone climate record to date, no firm conclusion can be made on this point.

2. No individual tropical cyclone can be directly attributed to climate change.

3. The recent increase in societal impact from tropical cyclones has been largely caused by rising concentrations of population and infrastructure in coastal regions.

4. Tropical cyclone wind-speed monitoring has changed dramatically over the last few decades leading to difficulties in determining accurate trends.

5. There is an observed multi-decadal variability of tropical cyclones in some regions whose causes, whether natural, anthropogenic or a combination, are currently being debated. This variability makes detecting any long-term trends in tropical cyclone activity difficult.

6. It is likely that some increase in tropical cyclone peak wind-speed and rainfall will occur if the climate continues to warm. Model studies and theory project a 3-5% increase in wind-speed per degree Celsius increase of tropical sea surface temperatures.

7. There is an inconsistency between the small changes in wind-speed projected by theory and modeling versus large changes reported by some observational studies.

8. Although recent climate model simulations project a decrease or no change in global tropical cyclone numbers in a warmer climate there is low confidence in this projection. In addition, it is unknown how tropical cyclone tracks or areas of impact will change in the future.

9. Large regional variations exist in methods used to monitor tropical cyclones. Also, most regions have no measurements by instrumented aircraft. These significant limitations will continue to make detection of trends difficult.

10. If the projected rise in sea level due to global warming occurs, then the vulnerability to tropical cyclone storm surge flooding would increase.

In general, I am not a fan of science by consensus. It is interesting, however, that you can get a bunch of scientists to basically agree that they don’t even know whether global warming will cause hurricanes to increase or decrease. The conclusion is especially surprising because no one ever wants to look like they don’t know the answers, and because scientists who work on hurricanes have strong incentives to convince everyone else of the important of their research. This statement clearly avoids that latter temptation.

Recently, a new study was released that flies in the face of the scientific consensus. Researchers Greg Holland and Peter Webster make the claim that global warming has nearly doubled the number of hurricanes over the last century. Reading between the lines of the various media reports on this study, I don’t think Holland and Webster have convinced many climatologists; in the four or five articles I read, there wasn’t a single endorsement from another scientist. One researcher actually came out and called it “sloppy science” in this Miami Herald report.

Also, could the timing of the article’s release be any worse? Two months into what was supposed to be a very active season, with 7-10 hurricanes predicted, so far not a single hurricane has appeared. By this time in 2005, there had already been three hurricanes. The biggest losers in all of this are the reporters — just think how much fun they could have had with this study had a hurricane been about to make landfall on the U.S. coastline.


The real bribe for junk science is coming from Exxon et al., the psychopathic corporations offering $10K, plus travel and expenses, to scientists sketchy enough to dispute scientific consensus on climate change.,,2004399,00.html


Science by consensus is the only way that science can be communicated to the public. This is a great example. Certain hurricane scientists said -- there is evidence that hurricanes are getting stronger and if this is true the public has to know about it as soon as possible, better safe than sorry. Of course they were right.

Other scientists said that the cause-effect link between current global warming and perceptibly stronger storms was not in the data. Of course they were right too.

The details of these arguments and paper after paper are too much for nonscientists to digest. The consensus view (uncertainties included) is what we should listen to.


The biggest losers may be natural gas futures traders...


For everyone's information:

Contribution to the "Greenhouse Effect," expressed as % of Total Based on concentrations.

Presented in the following order: Greenhouse Gas Name; % of All Greenhouse Gases; % Natural; % Man-made.
Water vapor; 95.000%; 94.999%; 0.001%
Carbon Dioxide; 3.618%; 3.502%; 0.117%
Methane; 0.360%; 0.294%; 0.066%
Nitrous Oxide; 0.950%; 0.903%; 0.047%
Misc. gases; 0.072%; 0.025%; 0.047%
Total; 100.00%; 99.72%; 0.28%

Paul Otis

I don't think any credible scientist has claimed that they can say whether or not a particular whether event like a hurricane is linked to global warming. Unfortunately, the nuances of how science works is lost on much of the public and also on many journalist that report on science. Propaganda from advocates on both sides of the issue often dominates the debate.

Global warming is a serious problem and we should be taking it seriously. When advocates of global warming exaggerate the link between global warming and the disaster in New Orleans they just make it easier to dismiss the whole issue.

The science behind global warming is complex and not that easy to explain in a sound bite. But, the overwhelming scientific consensus is that global warming is real and we are the primary cause. When a scientific theory gains “consensus” it is usually because the evidence is very convincing. There will always be variance from the consensus. There is always the possibility that a scientific theory can be wrong.

The global warming skeptics seem to require a level of absolute certainty that science is just not capable of ever providing. One can find people with scientific credentials that will tell you the Earth is about 5,000 year old. The scientific consensus is that the earth is 4.5 billion years old. Some may not like science by consensus, but when you are making policy choices the consensus matters. Otherwise, we can all just pick out the view that we find most convenient and reassuring to our own biases.



"In general, I am not a fan of science by consensus."

This statement and the pat, cynical Pavlovian-ish analysis of why a group of scientists come up with certain recommendations, and their "especially surprising" willingness to say what they don't know is a reflection of Levitt's ignorance of the process and thinking that are behind such a report.

There is nothing at all suprising about scientists expressing uncertainty; in peer reviewed scientific articles it is standard practice to explicitly discuss uncertainties and confidence levels.

When using computer models for predicting future climate patterns uncertainty is unavoidable. It is suprising to me that anyone would think otherwise. It seems that many non-scientists have an intuitive feel for the existence of these kinds of uncertainties; for the climate (or any other)scientist it is part of the "job." For example, the full report ( states: "Even for global mean temperature, uncertainties in future
projections are substantial."

Further, what the authors of the report have done is to review pertinent scientific literature in order synthesize a "current state of knowledge" (including uncertainties) summary about the connection between AGW and hurricanes. Confusing this process with Al Gore saying that there is a consensus on AGW, or how American public feels about the existence of consensus on AGW is, simply put, a boo boo.

That said, it seems that the underlying pupose of Levitt's is to undermine the credibility of those who correctly say that there is a strong consensus among climate scientists that AGW is happening. Again, it is important to understand that this consensus exists and is growing, and that it is based on extensive scientific study; scientists are producing more and better data, and are learning as they go.

A better way of phrasing predictions about the role of increasing tropical sea surface temperatures in triggering powerful hurricanes would be along the lines of:
"If our models are correct, we can expect to have between 5-8 years out the next 20 years where hurricane seasons will be on a par with what was experienced in 2005, and it is likely that there will be 1-3 years with more activity/severity than the historic 2005 season."

Predicting the details of what will happen this or next year, as pretty much any scientist will tell you, is very crapshoot-y.



Looking at Brent's numbers (which aren't sourced) a closer inspection of C02 shows that humans account for 3%, which is a non trivial amount, depending on what you are looking at. If the stock market dropped 3%, I think we would all be pretty upset. If my chance of dying today jumped to 3%, I would be pretty upset. Frankly, I trust the scientific community and their climate models on the subject more than I would trust myself or Brent.

The other thing I find fascinating is that everyone is so quick to bash scientist as money grubbing fear mongers. Really? If you are into science and picking your career based on your ability to make money, defense contracting is a much better way to go.

Finally, Beron makes reference to concern about the spread of HIV in comparison to the current concern about climate change. Since the alarmist reaction to HIV largely worked (at least for the developed world), leading to effective medical treatments for suffers and safer behavior for high risk groups.

...I am optimistic that the current global warming trend will be handled with a similar engagement of resources and brain power and pan out to be the same sort of manageable concern.



The Times Picayune clearly labels the Katrina disaster to be the result of bad engineering:

There have no reports so far linking the I-35W bridge collapse in Minneapolis with global warming.

Thomas Zaslavsky

I'm disappointed by Dr. Levitt's apparent failure to understand what science is, when he says scientists' coming up with a conclusion that doesn't serve their academic self-interest is "especially surprising". It does reinforce my impression (from other sources, such as the fact that economists of different schools of thought cannot agree on basics, and that they are very assertive about the rightness of their opinions) that economics is very different from science. It is interesting that viewing things as an economist makes it harder for Levitt to think of scientists as wanting to find out what's true rather than "prove" what suits their self-interest.


'There have no reports so far linking the I-35W bridge collapse in Minneapolis with global warming.

— Posted by David '

Well, it's not an official report, but the brainwashing has to start somewhere.

Ex-Clinton Official Ties Minneapolis Bridge
Collapse to Global Warming
By Noel Sheppard | August 7, 2007 - 00:12 ET

A former member of the Clinton administration, and current Senior Fellow at the virtual Clinton think tank the Center for American Progress, claimed Monday that global warming might have played a factor in the collapse of the I-35W bridge in Minneapolis last week.

I kid you not.

Writing at Climate Progress, the global warming blog of CAP, Joseph Romm - who served as Acting Assistant Secretary of the U.S. Department of Energy in 1997 and as Principal Deputy Assistant Secretary from 1995 though 1998 - stated in a piece amazingly entitled "Did Climate Change Contribute To The Minneapolis Bridge Collapse?" (emphasis added throughout):

I was skeptical at first, but after doing a Google search - and after NBC reported Sunday that National Transportation Safety Board investigators are "looking at everything" including "the weather" - I think it is a legitimate question to ask.

Keep your seatbelts fastened, for it got better:

Melissa Hortman of the Minnesota House of Representatives "speculated that 90-plus-degree heat Wednesday and the above-normal temperatures of the past two summers may have been a contributing factor," and said "You wonder if this bridge was built to withstand the massive heat we have had this summer." Or even if it was built to withstand heat, whether its structural deficiencies undermined the design integrity to a point where heat contributed to the collapse.


Some may object to even asking the question, "Did climate change contribute to the Minneapolis bridge collapse?" My guess is those are the same people who deny that global warming is caused by humans or that it is a serious problem - the same people who inevitably say "we can adapt to whatever climate change there is."

But, in my experience, those "adapters" are actually not interested in finding out what the impacts of global warming are. The Bush administration has blocked research into the impact of climate change on this country and muzzled climate scientists from discussing key climate impact issues, such as the connection between global warming and the recent increase in intense Atlantic hurricanes - which is obviously a central adaptation issue.

By the way, for those that have forgotten, CAP is the group headed by former Clinton Chief of Staff John Podesta which in June outlined a Democrat assault on conservative talk radio. But I digress:

Those who argue against strong action today to reduce greenhouse gas emissions - the adapters who are essentially saying to climate change, "Bring it on!" - cannot criticize those who then ask the obvious adaptation question - how will climate change impact this country and its infrastructure?

Certainly climate change will have the biggest infrastructure impact on our coastal cities, water and sewage systems, levees, and electric grid. But given that a remarkable 70,000 other bridges in the country are also structurally deficient, we should seek to learn whether such troubled bridges can take the ever-growing stresses generated by global warming. We need to be as prepared as possible for a changed climate - as the Center for American Progress has previously argued. Indeed, if the adapters have their way in blocking serious efforts aimed at prevention, we'll need to be prepared for the very worst.

Absolutely unbelievable.



viking: "I remember Al Gore's video implying a link between climate change and hurricanes, and damage therefrom."

At this point I am pretty convinced that anthropogenic climate change is an established fact, but it's also quite plain that Al Gore's 'documentary' is a propaganda vessel not overly concerned with accuracy.

Many people have defended the Katrina bit by saying he didn't actually claim a link between hurricanes and climate change, he merely (as you said) *implied* it.

... as if that makes it honest.

I don't doubt Levitt is 100% correct about Katrina being in part responsible for public awareness of climate change, even though they are probably coincidental. Also mostly coincidental is the hot summers we've had lately, and a couple of mild winters. Climatologists have no trouble saying that global warming is a broad trend that has only slight influence on any given local weather phenomenon. But I guess that message is too complicated to carry to the press.

I worry that we'll get a couple of cold winters and mild summers, and then the issue will fall off the political map. These things come and go even though the problem is real. Acid rain was like that.



Chris Mooney's newest book, "Storm World," is all about the global warming/hurricane debate. Worth the time to read.

Leigh Anne

Real Scientists dont 'want' anything other than to ask the right question and interpret the data correctly. Also, the hurricane record only goes back half a century or so. It will be a lot easier to predict hurricanes based on history with several multi-decadal oscillations on record.

Jeff Chmielewski

Leigh Anne, I believe that is one of the most important facts. Until the advent of weather satellites, hurricanes and other natural phenomena were only recorded when they happened to strike in a populated area or cross a shipping lane. If that didn't happen, they don't exist in our records. Fairly difficult to show a long term trend or a correlation when we don't have any data... and even if you can show the correlation, has any body proven causation? I think we should ban ice cream on account of the increased rates of drowning ;)

Drew Scot

Since I can't post on the terrorist blog... I really have to say you put the "FREAK" in Freakonomics!
Congratulations, doofus.


Being an actual New Orleanian who has spent a lifetime of summers watching storms track and where they go,Nobody seems to be discussing the normal- that larger cycles of weather happen and that includes "natural disasters" Or as we should call them nature just doing it's thing.
Florida has had the bejeezam kicked out of it by multiple hurricanes for many years, but it didn't quite make the national conscienceness. New Orleans has had this same scenario a number of times but there was no CNN and the Corps Of Engineers hadn't applied it's brilliance to forcing storm surge into the city then.
Is the greenhouse effect real? Yes, and it's time to clean up our act anyway for many reasons. But the hurricane thing is coming along on schedule, on cycle, and the Gulf Coast is in for more walloping.
Quit arguing and ride a bike.

JJ Cheo

The high number of hurricanes last year were caused by the El Nino phenomenon which warms the oceans.

This year is a La Nina season, whereby ocean temperatures drop.

Climate change exacerbates the intensity of El Nino and La Nina which in turn leads to a higher number of hurricanes and more "freaky" weather.

I believe that the change from El Nino to La Nina is the reason why there have yet to be any hurricanes in the USA.


Remember the gas crisis of the mid 1970's? Remember the Killer Bees from Africa that were going to infiltrate the entire southern US through Mexico / Texas?
Remember the massive asteroid that should have smashed into Earth already? I know...still could happen.
Remember when coffee was bad for you, then good for you, then bad, then good again?
One day, you'll remember when we all were up in arms about Global Warming.

John Barnes

The highest correlation between increases in the earth's temperature and any other factor is with solar flare cyles, and that correlation is very high. We are, and have been for a while, in the midst of a periodic, high level of solar flares. A solar flare involves 1 million tons of solar material blasting toward the earth at one million miles per hour. All of the CO2 that we could generate in our lifetimes cannot have that much impact on our planet.

Scientific research has demonstrated that over the last several hundred million years, the earth's average temperature has varied numerous times between 12 and 22 degrees celsius, with a mean of 17 degrees. Nearly all of that time with no influence from mankind, which was not even here. The current average temperature is about 14.5 degrees. We are coming out of a little ice age. Out current temperature is below "normal". Of course it is warming up, but we, as mankind, have little to do with it.

The other factor often ignored is tht most of the 100 year temperatures used by the chicken little scientists are from metropolitian areas, which have gone up. Those in most non-metropolitan areas have either not gone up, or went up very little. Given the nature of metropolitan growth over the last 100 years, one can conclude that the earth's temperature is rising at an alarming rate, or that concrete, asphalt and reflective glass are hotter than dirt, grass and trees. I know that the latter is true, but don't see sufficient data to buy that former.



I find it extremely ironic that it takes an economist to publicize a scientific consensus on a particular matter related to climate change. Funny, isn't it, that mainstream media has no interest in covering the opinions (never mind that these are probably correct) that have alarmist ring? Compare it to the tons of biased coverage thrown at the readers post-Katrina. Nine out of ten people to whom I spoke are convinced that Katrina is a product of global warming. Sadly, I don't believe many of them are going to read this blog, much less the consensus statement. Nevertheless, I applaud your effort.