Hurricanes and Global Warming: All You Need to Know
August 19th, 2006Posted by: Roger Pielke, Jr.
The current issue of the Bulletin of the American Meteorological Society (BAMS) has a lengthy commentary (PDF) by Judy Curry, Peter Webster, and Greg Holland offering their opinions on a wide range of subjects related to the recent debate over hurricanes and global warming. Beyond lengthy criticism of (see also Curry’s extended comments at Real Climate) the media, meteorologists, engineers, NOAA, NWS, Bill Gray, the AMS, the tropical storms list-serv, and the private sector (Did I miss anyone? How did I escape mention? 
), Curry et al. do tell those interested in an appropriate representation of the current debate all we need to know.
In the article, Curry et al. state clearly that the science of hurricanes-climate change is contested and differing expectations for what the future holds based on competing hypotheses won’t be resolved for at least a decade:
In summary, the central hypothesis and subhypotheses
cannot be invalidated by the available evidence. We anticipate that it may take a decade for the observations to clarify the situation as to whether the hypothesis has predictive ability. In short, time will tell.
This echoes what we wrote in 2005 in BAMS (PDF):
. . .the state of the peer-reviewed knowledge today is such that there are good reasons to expect that any conclusive connection between global warming and hurricanes or their impacts will not be made in the near term.
At last year’s AMS meeting Webster and Curry presented an earlier version of this paper and cited Bertrand Russell on skepticism (also cited by RealClimate here):
There are matters about which those who have investigated them are agreed. There are other matters about which experts are not agreed. Even when experts all agree, they may well be mistaken. . . Nevertheless, the opinion of experts, when it is unanimous, must be accepted by non-experts as more likely to be right than the opposite opinion. The scepticism that I advocate amounts only to this: (1) that when the experts are agreed, the opposite opinion cannot be held to be certain; (2) that when they are not agreed, no opinion can be regarded as certain by a non-expert; and (3) that when they all hold that no sufficient grounds for a positive opinion exist, the ordinary man would do well to suspend his judgment.
The issue of hurricanes and global warming is clearly is in Russell’s category (2), and according to Curry et al. will remain there for at least a decade. What this means is that (a) those who claim that science has demonstrated no linkage between hurricanes and global warming and (b) those who claim that science has demonstrated a linkage are both misrepresenting the available science. We should expect scientists in competing camps to argue strenuously for their own perspective. This is what Curry et al. have done as well as those scientists holding a different view. But for those of us not participating in the science, picking sides reflects factors that go well beyond the science. As we wrote in BAMS in 2006 (PDF), “we should not make the mistake of confusing interesting hypotheses with conclusive research results.” And as Rick Anthes has written, “it will be a number of years—perhaps many—before we know the relationships between climate change and the various characteristics of tropical cyclones.”
The good news is that policy related to hurricanes is in no way dependent upon resolving this ongoing debate, as Curry, Webster, Holland, and seven of their colleagues from various camps in the debate have wisely recognized.
As we have said all along, (1) the debate is contested, and will remain so for the the indefinite future, and (2) the debate is not relevant to policy actions related to hurricanes. And that is all you need to know.
August 20th, 2006 at 3:14 pm
Roger,
You are absolutely correct that we need policies that address the hurricane problem regardless of any anthropogenic effect that may or may not be playing a role. Policies need to be developed that address building construction, community planning, government response and insurance practices. This should be the focus.
While the authors have given lip service to this, (your ‘wisely recognized’ link above) their other writings, including this article, generally ignore this point. In their summary they write:
“The debate has clearly shown that some of the most challenging issues in our field that are also of the highest policy relevance are at the interface of climate change and weather extremes.”
The AGW/hurricane intensity debate is not ‘of the highest policy relevance’ because required policy is no different whether hurricanes exhibit an AGW signature or not! It is because of statements like this, that I believe the authors and the AGW community in general want to use the hurricane argument to advocate the restriction of GHG emissions, not reduce the death and damage caused by tropical cyclones worldwide.
August 20th, 2006 at 3:35 pm
Dear Mr. Clark,
With due respect, you presume too much about from what we write. Please feel free to criticize our science: fair game. But don’t read into our work the message that you might want to hear. Where can you find evidence “….that I believe the authors and the AGW community in general want to use the hurricane argument to advocate the restriction of GHG emissions, not reduce the death and damage caused by tropical cyclones worldwide…” . I believe that this is a remarkable suggestion. I cannot speak for the “..rest of the GHG community..” with whom you group us as you should not speak about our motivations without justification. Please try http://cfab2.eas.gatech.edu to see what we try and do to “..reduce death and damage..” in the developing world. Clearly not for advocacy of some GHG agenda!
It is easy and convenient to presume motivation of others. It is harder to think through arguments and make a thoughtful contribution to an argument.
August 20th, 2006 at 3:44 pm
On a side note…the authors listed the arguments against their hypothesis (sometimes incorrectly) and attempted to address each one. The first three were dismissed without comment for being illogical fallacies. I totally agree with this assessment and note with some irony that these three arguments have been the primary arguments leveled against skeptics for over 15 years now.
1. Appeal to authority (IPCC, consensus)
2. Ad hominem (not qualified to comment)
3. Appeal to motive (in the pockets of big oil)
The authors use the very same logic they dismiss with little comment, to attack their opponents in this document as well as other papers, testimony and editorials. It is almost amusing that they seem truly hurt and offended by such accusations, then turn around and toss the same accusations at those who disagree with their science.
I also strongly object to the term ‘greenhouse warming deniers’! I know of no such creatures, but I know plenty who are skeptical of an impending climate crisis due to CO2 and other trace gas emissions. Casting their scientific opponents as people who deny a rather basic physical fact is insulting. Even the most strident crisis skeptics have always agreed that increasing atmospheric CO2 has a warming effect. The disagreement has always been about the magnitude of that warming and what effects (good and bad) it could have.
I would hope that the call for civility would be heard and accepted by both sides of the policy and scientific debate.
August 20th, 2006 at 5:54 pm
Peter (and Judy if you are reading)-
You say that it is a “remarkable suggestion” to associate your views with a GHG reduction agenda based on hurricanes.
But is your team sending a mixed message on this subject? Over at RealClimate Judy writes:
“I also think that the responsible NGO’s have set a good example by having their public relations departments explain the science, even with the political spin. For example: Environmental Defense . . .”
http://www.realclimate.org/index.php/archives/2006/08/fact-fiction-and-friction/#comment-17990
She cites ED’s Bill Chameides in particular as an effective communicator.
http://www.realclimate.org/index.php/archives/2006/08/fact-fiction-and-friction/#comment-17984
So I go to the ED WWW site and I read an essay by Dr. Chamiedes that includes the following:
“Katrina-like events will become more common and more widespread unless the emissions of global warming pollutants are capped. The link between global warming and hurricanes is yet another reason for Americans to insist on meaningful legislation to cap our greenhouse gas emissions.”
http://www.environmentaldefense.org/article.cfm?contentid=5315&campaign=486
There is a bit of a mixed message here being sent by your team. Do you endorse his views of the policy releavance of your science, or not?
Thanks!
August 20th, 2006 at 7:55 pm
Roger,
I did NOT write the statement
“I also think that the responsible NGO’s have set a good example by having their public relations departments explain the science, even with the political spin. For example: Environmental Defense . . .”
http://www.realclimate.org/index.php/archives/2006/08/fact-fiction-and-friction/#comment-17990
This was written by Joseph O’Sullivan, not me
For the record, and i have stated this numerous times on your blog. Neither Peter nor I advocate any specific policies relative to AGW. We have been talking with and working with a variety of groups ranging from emergency managers, insurance companies, energy traders, NGOs and advocacy groups, etc. to help them have access to the best available scientific info for them to use in their activities on emergency management, advocacy, whatever.
I refer readers to realclimate where a substantive discussion on this paper and the broader issues is underway, which doesn’t seem to be happening on prometheus.
Judy
August 20th, 2006 at 8:20 pm
Thanks Judy for the clarification. But did you write the following?
“Recently my colleague at Georgia Tech Bill Chameides “retired” after 25 years and became the chief scientist at the Environmental Defense Fund. Bill has heavy credentials (NAS) and is an outstanding communicator (he is also a trained actor); I expect that Bill is someone who can really make a difference. And there are many other such examples.”
Here is what Dr. Chameides has written:
“Katrina-like events will become more common and more widespread unless the emissions of global warming pollutants are capped. The link between global warming and hurricanes is yet another reason for Americans to insist on meaningful legislation to cap our greenhouse gas emissions.”
http://www.environmentaldefense.org/article.cfm?contentid=5315&campaign=486
August 20th, 2006 at 8:36 pm
“As we have said all along, (1) the debate is contested, and will remain so for the the indefinite future, and (2) the debate is not relevant to policy actions related to hurricanes. And that is all you need to know.”
Roger, (1) is entirely wrong since (a) your side (tribe?) has been a little thin on papers refuting a TC-AGW link while the pile on the other side is getting to be pretty impressive and (b) it won’t be very long at all since all that’s needed, as Judy noted, is no more than a decade or so of further records to demonstrate the predictive ablity of the new theory. (2) is also wrong since the same could be said for any of the impacts of GHG warming because of the multi-decade lag in seeing the effects of whatever we do in the present. I would have thought that a science policy wonk would be the last person to advocate for ignoring the long-term effects of policy changes, but apparently I’d be wrong. You’re absoutely correct that there’s a lack of sufficient preparation for natural levels of all sorts of weather activity, many aspects of which will be exacerbated by AGW (and western U.S. drought is a much more extreme example of this than hurricanes, IMO), but in each case the prospect of increased future harm is a really good reason to begin GHG reductions now.
August 20th, 2006 at 8:54 pm
Steve-
Thanks for your comments, but you have mischaracterized my views (again). Please indicate where I have taken a “side” in the scientific debate? I haven’t. Pielke et al. (2005) and (2006) clearly set forth my views. I, like you and most everyone else, am stuck with Russell’s (2) for the indefinite future.
As a spectator, you are of course free to take sides and predict where future science will go — its kind of like a football game! (I hope your team wins!;-) For my part, I am happy to await that decade or so before rendering a judgment.
BTW,do you have any references to papers on the effects of GHG reductions on (a) hurricane behavior, and (b) huricane impacts? Didn’t think so
August 21st, 2006 at 6:28 am
Roger, yes I wrote the statement about Bill Chameides. Bill Chameides is apparently doing a very good job in his position at the Environmental Defense Fund. This does not mean i endorse what Bill or anyone else says regarding policy options. I frankly do not see much to object to in Bill Chameides statement (which does not mean however that i endorse it). 100 years from now, if global warming proceeds as expected, there is a risk for whopper hurricanes with sea level rise making the risk even worse for our coastal cities. The elevated risk in terms of hurricane activity may already be upon us. No one wants to see coastal cities disappear. You are right that actions like limiting greenhouse gas emissions cannot help the hurricane situation in the short term (20 years or maybe even 50 years), but on the century time scales there should be some impact at least on the rate of sea surface temperature increase (it is the century time scales that the washington post editorial addresses). Hurricane Katrina, even tho there was no direct causal link with global warming, has served as a huge wakeup call to the American public that global warming might actually have some seriously adverse impacts if we were to see such storms more frequently in the future (this issue seems to have a much greater impact on the public than melting of polar ice gaps). The risk is there, science is important to the public and decision makers, and people are starting to talk about policy options both for the short term and the long term (e.g. the washington post editorial). Surely this is a good thing. Step back for a minute and reflect on why your position on this is so often misrepresented, misunderstood or ignored. There would be more traffic on prometheus on this issue if you would be more reflective about what the other people are trying to say, rather than trying to fit everything into something that supports your thesis (not sure how our BAMS article fell into that category) or makes no sense because it doesn’t support your thesis (e.g. the washington post editorial).
August 21st, 2006 at 10:21 am
Dear Dr. Webster,
Please understand that I do not know you or your co-authors personally and that I do not, in anyway, presume to know what motivates you. My comments are strictly based on the words and arguments that you have presented in discussions of hurricanes and AGW. Allow me to explain, and I think you will see that my deductions are not only reasonable, but, in fact, the only conclusions that fit the available data.
In the ‘Statement on the U.S. Hurricane Problem, July 25th 2006’, you, your co-authors and others conclude:
“But the more urgent problem of our lemming-like march to the sea requires immediate and sustained attention. We call upon leaders of government and industry to undertake a comprehensive evaluation of building practices, and insurance, land use, and disaster relief policies that currently serve to promote an ever-increasing vulnerability to hurricanes.”
I could not agree more with this statement and have said as much in my original post on this topic. It captures the most important issues regarding the threat of hurricanes today and leads to the conclusion that effective hurricane policy for ‘natural’ storms is equal to effective hurricane policy for storms that may be more AGW enhanced in future decades. In other words, the most important policy issue is that we deal with the threat hurricanes, and there is no significant difference in the most effective policies whether hurricanes become AGW enhanced or not! Effective policy prepares communities for storms, regardless if the threat of a major hurricane is 3% annually or 3.5% annually.
Now consider what has been expressed in this current BAMS article and in other papers, editorials and testimony by the authors on this subject. In these cases the argument is made that the amount of AGW enhancement to hurricanes is extremely policy relevant and there is no mention whatsoever of the admittedly more important issues of hurricane policy. I thought I demonstrated this in my original post when I quoted the sentence from the current BAMS article that used the phrase ‘highest policy relevance’ in reference to the AGW/hurricane debate.
We have already established that effective hurricane policy deals with the threat of hurricanes and does not change if the risk of a major hurricane goes up or down slightly. If AGW enhanced hurricanes are claimed to be of the ‘highest policy relevance’, what policy could that be referring to? Not effective hurricane policy. Nor any other policy I can think of other than one that curbs GHG emissions.
I am not the only one who has reached this conclusion based on what you have written. The Environmental Defense website and the Washington Post ob-ed, that Roger addresses elsewhere, are examples of others who have reached the same conclusion based on your previous works. You may argue that this is not what you intended, but it is the message that your words convey. What other conclusions are we to draw from your statements about policy relevance? How can we conclude from your arguments (outside of the July 25th statement) that you are not emphasizing GHG reductions over much more effective hurricane policy?
It is quite evident that the AGW crisis community is using your work to promote the reduction of GHG emissions. It is also quite evident that such policies will not effectively reduce the death and damage caused by tropical cyclones in our lifetimes, and maybe never.
I am not questioning your motivation, nor do I even care what your motivation is. I am addressing what you have written and the effect those arguments and statements have on the policy debate.
I encourage you and your co-authors to be extremely explicit when referring to policy relevance in the future, emphasizing the thoughts you expressed on July 25th and/or refraining from inflating the policy relevance of potential GHG enhanced hurricanes.
Sincerely and with respect,
August 21st, 2006 at 10:53 am
Hi Jim,
You write, ” Policies need to be developed that address building construction, community planning, government response and insurance practices. This should be the focus.”
Let’s not be too hasty!
Have you even considered the possibilities that:
1) Hurricanes could be reduced in strength by “geoengineering” methods (e.g. cooling surface water or reducing its ability to evaporate)?
2) “Temporary hurricane protection walls” could be constructed?
With that second item, I’m thinking of the possibility of transporting and and laying giant “water tubes” that extend the length and height of the hurricane’s storm surge. Take, for example, a hurricane that produces a maximum storm surge of 25 feet at the center, decreasing to 3 feet 100 miles to either side of the center. (Roughly a Category 4/5 hurricane.)
Therefore, the total length of the tubes would be 200 miles (about 300 km). They be 25 feet above calm sea level at the center, and only 3 feet above calm sea level at the edges.
If such a tube system could be developed for $10,000 per linear meter (it seems to me that should be doable) the cost would be $10 million per kilometer, or $3 billion for the entire 300 kilometers.
Let’s further say that it costs $1 billion each time to deploy the system. That’s still VERY cost-effective, compared to fortifying both the Gulf and East coasts against hurricanes! (Also imagine if such a system had been available for Katrina…damages would have been reduced to a tiny fraction of the estimated $100 billion cost!)
Mark
August 21st, 2006 at 2:29 pm
Mark,
You might want to think your water tube idea through some more.
I think you’ll find the logistics simply won’t work.
How much equipment and manpower is going to be necessary to deploy the system in a timely manner? They can’t be sure of the landfall target more than 24hrs out.
August 21st, 2006 at 2:49 pm
Mark,
I am a great fan of science fiction and someday in the distant future, suggestions like yours may be realistic, but I see way too many problems with your suggestions at this point in time.
For example,
Your suggestions about reducing the strength of storms by covering or cooling the water would likely have extreme environmental consequences. Since much of the concern over AGW is that it will generate extreme environmental consequences, you may not have much approval for such actions.
Temporary hurricane walls are a logistical nightmare. Where do you store them? How do you deploy them? How do you anchor them? How do you deal with rivers and streams (keeping the ocean out but allowing rivers and streams to continue draining)?
The average forecast error for 24 hours is near 70 miles in either direction. For 3 days or more, the average error is over 200 miles. If the storm is approaching the coast at an angle, the 70-mile error can translate into many hundreds of miles of coastline, making deployment impossible.
There are many more reasons, costs and complications involved, but here is one that you might not have anticipated. Lawyers! If the hurricane hits ‘naturally’ there is little that lawyers can do. If humans have any effect on a hurricane, real or alleged, the lawsuits will fly faster than the storm winds. This has already happened with simple cloud seeding experiments, and suits have been recently filed over the speculation of AGW effects!
The litigious aspects alone make it unlikely that any direct meddling with the ‘natural’ course of these storms will be cost effective.
I hate to be a spoil-sport, but the most cost effective and realistic mitigation of hurricanes remains in building, planning and insurance.
August 22nd, 2006 at 10:29 am
Bob K writes, “You might want to think your water tube idea through some more.”
No, I think I’ve thought about it enough (maybe 3-4 hours, total) that it can go straight to full-scale deployment.
Assuming such a system would cost several billion dollars, *obviously* it would require a lot of thought! If I remember correctly from my days designing waste-to-energy plants, the Engineering arm of the company (in which I worked) typically charged about 5% of the overall project cost. (That’s as opposed to the Construction arm.) Assuming this tube system was a $3 billion system, that would mean total engineering costs of $150 million. Even at $100 per person-hour, that would be 1.5 MILLION hours of engineering! At 2000 hours per year, that’s 750 person-years, just for engineering!
So obviously thinking 3-4 hours about it isn’t going to solve all the problems, or even identify whether “deal breaker” problems exist.
“I think you’ll find the logistics simply won’t work.”
I think you’ll find that the logistics of digging large tunnels under the English Channel won’t work. I also think you’ll find that digging a canal across the Isthmus of Panama using pre-WWII technology won’t work.
“How much equipment and manpower is going to be necessary to deploy the system in a timely manner?”
Well, that would depend on many, many things. For example, are the tubes going to be placed on shore, or in the water? If in the water, how deep? How long will the tubes be? (For example, maybe it would make sense to only have the tubes 50 miles long and extending a mile onto shore, even though that would mean that there would be significant damage outside those tubes.) If the tubes were joined together, how would they be joined? How would they be filled (many small pumps, or several large ones)? Etc. etc. etc.
“They can’t be sure of the landfall target more than 24hrs out.”
Yes, that’s merely one of hundreds (or thousands) of problems that need to be addressed. The total length of the U.S. Gulf Coast is 1630 miles (2600 km). The total length of the Atlantic coast from Florida to Boston is approximately 1700 miles (2700 km). Assuming a capital cost for the tubing of $10,000,000 per kilometer, the total cost to get enough tubing to cover *all* of *both* coasts would be $53 billion. That’s obviously a lot of money.
http://www.infoplease.com/ipa/A0001801.html
But even that amount is exceeded by approximately a factor of two by the storm surge damage caused by ***one storm*** (Katrina)!
So rejecting out of hand the idea of water-filled tubes forming temporary surge wall protection is foolish and illogical.
August 22nd, 2006 at 10:37 am
Heh, heh, heh!
I see the software deleted by “end sarcasm” symbol after my statement:
“No, I think I’ve thought about it enough (maybe 3-4 hours, total) that it can go straight to full-scale deployment.”
That’s probably just as well…
August 22nd, 2006 at 7:21 pm
Hi,
I have somewhat-lengthy
responses to Jim Clarke’s comments on hurricane mitigation techniques. I’ve spared everyone the gory details by posting them on my own blog:
http://markbahner.typepad.com/random_thoughts/2006/08/some_responses_.html
However, there is one response I think is worth cut-pasting here. Jim wrote: “I hate to be a spoil-sport, but the most cost effective and realistic mitigation of hurricanes remains in building, planning and insurance.”
In response to that, I have the same sort of questions that I had for Judith Curry:
1) In the last 20 years, what has the damage from storm surge averaged in the United States?
2) In the 2040-2060 period, what do you expect the damage from storm surge to average without any of the measures you advocate?
3) In the 2040-2060 period, what do you expect the damage from storm surge to average with the measures you advocate?
4) What do you think is the cost of the measures you advocate?
If you can’t answer these questions, then I don’t think you can say what is the “most cost effective and realistic mitigation of hurricanes.”
P.S. I freely admit I can’t answer these questions for the mitigation techniques I propose (e.g. hurricane strength reduction or temporary storm surge walls). But I’m not saying any of my ideas *will* be the most cost-effective and realistic techniques. Just that they *might* be, and are (definitely) worth further study.
August 22nd, 2006 at 8:05 pm
Hi,
Here are some photographs that give impressive testament to the strength of storm surge. One can write all one wants about “building design” to mitigate for hurricanes, but I think the fact is that no one-story or two-story structure is going to withstand storm surge that actually floods the structure nearly to the roof.
http://coastal.er.usgs.gov/hurricanes/rita/photo-comparisons/cameron.html
http://www2.sunysuffolk.edu/mandias/38hurricane/richelieu.gif
http://www.livescience.com/php/multimedia/imagedisplay/img_display.php?pic=ig20_hurricane_01_02.jpg&cap
This final site is particular impressive. It gives animations for the flooding of Long Island (Suffolk County and Nassau County), NY, for increasingly strong hurricanes (Categories 1 to 4…they don’t model Category 5 because one has never struck New York). Click on the “All maps animation,” and prepare to be dazzled:
http://www2.sunysuffolk.edu/mandias/38hurricane/storm_surge_maps.html
And then go to Google Earth to see what those areas look like from an aerial photo:
http://earth.google.com/
We’re talking about literally hundreds of thousands of people who would probably be rendered homeless. (Unless they were protected by the miracle of water-filled tubes, of course!
)
Mark
August 23rd, 2006 at 7:34 pm
Hi Roger,
Y’know, this water tube storm surge protection wall idea looks *very* promising.
Have you done any work that breaks down the economic losses from hurricanes into separate component parts (e.g., storm surge, wind damage, inland flooding)?
If not, do you know anyone who has?
Thanks,
Mark
August 24th, 2006 at 6:31 am
Mark- Thanks. I am not aware of detailed breakdowns of this sort, though there is a range of loss information available. I discussed some of this here:
http://sciencepolicy.colorado.edu/prometheus/archives/disasters/000563part_ii_historical.html
Thanks!
August 25th, 2006 at 10:51 am
Yes the comment on RealClimate that Rodger initially mentioned was written by me. The link I provided was to the “Ask Dr. Bill” section where people could send in questions about global warming.
I though that this was a good attempt to reach out to the public, even though not everyone agrees with the policies Environmental Defense advocates.