Hurricanes and Global Warming
November 21st, 2005Posted by: Roger Pielke, Jr.
It has been called, “absurd,” “shameful,” and “crazy.” Now it can be called something else — published. Here is our assessment of the current state of the literature on hurricanes and global warming.
Pielke, Jr., R. A., C. Landsea, M. Mayfield, J. Laver and R. Pasch, 2005. Hurricanes and global warming, Bulletin of the American Meteorological Society, 86:1571-1575. PDF)
Comments on the substance of the paper are welcomed.
November 21st, 2005 at 9:22 am
It strikes me that we may not even be sure how many storms there were in years prior to the advent of weather satellites. Those of us who live on the US Gulf Coast saw many comparisons between this year’s activity and those in the mid 1930s. However, a hurricane that developed and stayed over the mid-atlantic may not have been detected prior to satellite observations. Most surface ships that sailed into the eye of anything larger than a category 3 would likely have not made it to port to report the severity. I really haven’t seen this observation problem addressed in any of the articles tracking hurricane number and severity of hurricanes compared with other climate factors.
November 21st, 2005 at 10:10 am
A challenge for Roger:
You have been very effective in showing the flaws in arguments that some people have offered for taking action to mitigate global warming. Though certainly not your intention, you have thereby given amunition to global warming deniers. Since you say your are not a denier, what arguments do you think can be made legitimately and forcefully in favor of action to mitigate global warming? I’m not referring to arguments for taking steps to reduce the societal impacts. And most of us, I assume, are familiar with the case for decoupling energy policy from climate change science (because increasing efficiency, finding alternatives to fossil fuels, etc., make sense on their own merits).
Perhaps you believe that the threat of global warming per se does not help make a strong case for reducing greenhouse emissions, period, and that we therefore shouldn’t even bother with this argument at all. If so, I’d like to hear that from you. If, on the other hand, you believe the risks from global warming can and should help us argue in favor of policies that would reduce greenhouse emissions, how do you recommend we frame that argument for the public and policy makers?
November 21st, 2005 at 10:44 am
Thanks Tom, I’d be happy to weigh in, but first a clarification from you. You write, “I’m not referring to arguments for taking steps to reduce the societal impacts.” Isn’t the goal of climate policy to address concerns about future societal and environmental impacts? What other goal for climate policy do you have in mind?
Remember, reducing emissions is a means not an end.
November 21st, 2005 at 12:15 pm
Tom Yulsman wrote:
“Though certainly not your intention, you have thereby given amunition to global warming deniers.”
Those who are skeptical of the dangerous warming scenarios of the IPCC have been called many things. Few, if any, can be charachterized as ‘global warming deniers’. Several years ago, there were some who stated that the lower troposphere was not warming, due to the evidence provided by satellite and balloon data, which at the time did not indicate any warning. By 1998, there was an obvious warming trend in the data and I know of no one who denied that. The recent re-calibration of the satellite and balloon data adds more evidence of recent warming, and no one denies that. So I am not sure what you mean by ‘global warming deniers’.
If you are refering to those who are skeptical of the magnitude of global warming due to human influence projected by the IPCC, then there are many, but they do not deny anything that is actually measured in the atmosphere.
As a skeptic, I must question your statement above. Are you saying that factual information should be suppressed if it lends support to the competing theory? Should we only publish information that supports the prevailing dogma? Should anyone publishing any paper that provides solid data and reasoning, yet does not support severity of the proposed anthroprogenic global warming, be subject to ethics related questions? Do we need a Spanish inquisition for climate science?
The data is what it is and the logical conclusions are what they are. If that doesn’t support your world view, then that is too bad!
November 21st, 2005 at 12:27 pm
Jim Clarke and Tom- On your discussion of my work that lends support to one camp or another, please see this essay I wrote a while back on the same subject:
http://sciencepolicy.colorado.edu/zine/archives/1-29/28/editorial.html
Also, for Tom, if the “global warming deniers” (whomever you meant by that) are using my work, shouldn’t that be encouraging? I do good work
November 21st, 2005 at 1:52 pm
Blimey Roger
I’m beginning to see why Dano gets so frustrated with you!
I’m afraid I didn’t have 16 dollars to spare to read the ‘implications’ report. However, I have to say that having read the essay I’m still none the wiser about how you propose this non-partisan scientific engagement to proceed. It seems to me that you too must enjoy similar pursuits to Kevin V. Only it’s not the elk you’re after it’s any scientist sticking their head over the parapet unaware of your exacting (yet totally recondite) rules of engagement.
D’oh, I let slip I’m a believer…BANG!
Regards
Hugh
November 21st, 2005 at 2:02 pm
Hugh- Thanks for your comment, but I am not sure what you are referring to — “implications” report?
I’ll be concise: Some groups in the scientific should serve as “honest brokers of policy alternatives.” What do I mean by that? See this post:
http://sciencepolicy.colorado.edu/prometheus/archives/science_policy_general/000405honest_broker_part_.html
What groups ought to serve as honest brokers? Well, those that advertise themselves as such, like the IPCC. Also, it is very difficult to build a wall around science and try to exclude political and social considerations in the sdvisory process. This is well established. More generally, science academies, presidential advisory panels, and internationall science assessments should strive to serve as honest brokers of policy alternatives.
And if individual scientists have strong political views, then good for them (they are humans after all!). Just don’t hide behind science when advocating your political preferences, because that hiding behind science politicizes the science.
How was that?
Does anyone want to talk about our paper?
November 21st, 2005 at 2:08 pm
A Challenge to Tom Yulsman
Reading everything I can find about climate change has been my main preoccupation for fifteen years. Today I do not know of a single climate qualified individual who could be called a “denier”. The following facts are not disputed. The earth is in a warming trend, man affects climate, carbon dioxide produces a greenhouse affect. How you link these and what other information is relevant creates many points of view. This results in dispute and that is the very lifeblood of scientific progress. It seems that those who want to squelch debate are either ignorant of science or scornful of it.
Climate science is near the top of my list of disciplines with the most uncertainties. Fascinating discoveries are reported everyday that blow away previous assumptions. Yes some of these scientists display a certainty that there is no need for concern or a cerrtainty that disaster is on the way. But there are a myriad of positions in between. The stupid terms like “settled science” and “mainstream” do not apply.
I find that certainty exists primarily among journalists, probably because their discipline has a different process for uncovering truth. Yet The New york Times’ Andrew Revkin’s recognition of the uncertainty in science is encouraging and I hope the start of a new trend.
Finally, suppose it were obvious that mitigation is called for, just what could be done? Expand the Kyota joke that has not achieved a thing so far? Should we give a command and control function to a dysfunctional US government or a corrupt UN? But then if you could find an appropriate agency what would they do? Brow beat the US who’s economic future looks like it will produce less CO2 rather than more? We do know that hysteresis says that absolutely nothing can be done to change climate trends for the next twenty years. At that time your mitigation efforts will have to be aimed almost entirely at China and India since they will be the real big producers of CO2. Do you think they will worship computer models rather than continuing their historic efforts to lift themselves out of poverty?
Perhaps it would be worthwhile to reconsider your dismissal of reducing societal impacts. An open-minded journalistic campaign along these and other new lines would be much more welcome than the current one led by Polyanna and Don Quixote.
November 21st, 2005 at 6:29 pm
Hi Roger,
As an outsider, I find this an interesting review of climate and extreme weather. I do have a few questions, though:
On science certainties. The paper states, “it would be premature to conclude with certainty that such a link exists or is significant”. Absence of evidence isn’t evidence of absence, however. What level of evidence is required for the decision processes? And where would the evidence be first expected to appear — in a direct connection between GHG and hurricanes (eg the statement that “no connection has been established between greenhouse gas emissions and the observed behavior of hurricanes”) or rather through some understanding of mechanism? The science is so complex that little can be said. How little? Is there at least agreement about the sign (positive or negative) of the change in rate of extreme weather, or is even that under dispute?
On policy. The paper also states that individual weather events cannot be causally connected to human GHG, even if the trend can be. Couldn’t the same statement be made about correlations wrt virtually every complex phenomenon, say smoking and lung cancer? Should we be neutral about smoking, then?
With respect to the relative sizes of variability of one group’s prediction of economic growth vs. extreme weather losses, to me this seems like a statement that lung cancer death increases from smoking are lost in the noise of traffic deaths. (A statement surely true in the short term, and perhaps the long term as well.) Again, would this mean that smoking is irrelevant?
Finally, I don’t know what you mean by “political”. I read the press release given as an example, and didn’t see any clear party affiliation associated with it. Does it mean the advocacy of any policy position with which you personally disagree? Do you consider your work political or apolitical?
Thanks!
November 21st, 2005 at 7:47 pm
TFox-
Thanks much for your questions. Some answers below.
You write: “On science certainties. The paper states, “it would be premature to conclude with certainty that such a link exists or is significant”. Absence of evidence isn’t evidence of absence, however. What level of evidence is required for the decision processes?”
Reply: This is a key point in our paper. Even a 100% level of evidence of a connection between global warming and hurricanes is unlikely to radically change the ordering of policies most likely to be effective with respect to addressing future hurricane damages. This is because of the overwhelming influence of growing societal vulnerability to storm impacts.
You write: “And where would the evidence be first expected to appear — in a direct connection between GHG and hurricanes (eg the statement that “no connection has been established between greenhouse gas emissions and the observed behavior of hurricanes”) or rather through some understanding of mechanism?”
I’m no climate scientist, but my understanding is that frequently in this area a theoretical understanding comes well before observations are available under that theory. In the context of our paper, we specifically referred to observations in the statement that you point to, and elsewhere we write that there is a theoretical basis for understanding how intensity might change in the future, but much less of a basis for understanding frequency.
You write: “The science is so complex that little can be said. How little? Is there at least agreement about the sign (positive or negative) of the change in rate of extreme weather, or is even that under dispute?”
I address this question in some detail here:
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/000312climate_change_and_r.html
and here
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/000321climate_change_and_r.html
You write: “On policy. The paper also states that individual weather events cannot be causally connected to human GHG, even if the trend can be. Couldn’t the same statement be made about correlations wrt virtually every complex phenomenon, say smoking and lung cancer? Should we be neutral about smoking, then?”
Reply: No. There is strong evidence that smoking is casually connected to lung cancer. Such causality is not yet present in the case of hurricanes, at least as found in the peer reviewed literature, though as we state in the paper, recent studies are suggestive of a connection. Of course there is a question that follows as well, how effective are proposed policy interventions with respect to the desired outcome.
In the case of hurricanes from a policy perspective, simply establishing a causal connection won’t make much difference. Just about every hurricane scientist agrees that we will see more storms in coming decades no matter what climate policies are adopted.
You write: “With respect to the relative sizes of variability of one group’s prediction of economic growth vs. extreme weather losses, to me this seems like a statement that lung cancer death increases from smoking are lost in the noise of traffic deaths. (A statement surely true in the short term, and perhaps the long term as well.) Again, would this mean that smoking is irrelevant?”
Reply: Here is what we said in an essay earlier this year, kind of the inverse of your analogy: “Prescribing emissions reductions to forestall the future effects of disasters is like telling someone who is sedentary, obese, and alcoholic that the best way to improve his health is to wear a seat belt.” I’m not sure that it is the best analogy, but as we say in our BAMS paper, “There are much, much better ways to deal with the threat of hurricanes than with energy policies (e.g., Pielke and Pielke 1997). There are also much, much better ways to justify climate mitigation policies than with hurricanes (e.g., Rayner 2004).”
You write: “Finally, I don’t know what you mean by “political”. I read the press release given as an example, and didn’t see any clear party affiliation associated with it. Does it mean the advocacy of any policy position with which you personally disagree? Do you consider your work political or apolitical?”
Reply: By politics I mean bargaining, negation and compromise in pursuit of desired ends. Political is not the same as partisan. Efforts to reduce the scope of policy choice are clearly political. There is nothing wrong with politics; it is how we do the business of society. Efforts to use recent hurricanes and their impacts as justification for changes to energy policy to reduce future hurricane damages are clearly political. Efforts to use recent hurricanes to justify reducing vulnerability to reduce future hurricane damages (i.e., my position) are also clearly political. Question is, do you have good reason to expect that one course of action might be more effective than another? Questions of the effectiveness of alternative courses of action are policy questions for which some answers are arguable better than others.
Thanks again.
November 22nd, 2005 at 10:14 am
Hi Roger,
Thanks for your time and your responses. I think I’m starting to understand your point of view better.
WRT the link, I’m understanding you to say that 100% certainty would not convince you of the significance of the link, because you already know what the appropriate policy choices are, and they do not depend on the link. This makes sense to me. Unfortunately, this also means that I can’t rely on this assessment of the link’s significance until I am also convinced by the assessment of the policy choices. Since consensus on policies has not yet developed, assessments of the link which at least attempted to be policy neutral would be more useful to those attempting to think through the policy implications.
I think we’re on pretty much the same page on the smoking / accident analogies. Society does, in fact, tell sedentary obese alcoholics to wear seatbelts, as indeed they ought to. Obviously, there are other things they ought to do too. Given the lousy effectiveness of weight loss and addiction treatment programs, however, I think it’s open to debate which one thing would be “best”. Since they aren’t mutually exclusive, it’s moot.
On the history of the evidence against smoking, it’s easy to say in 2005 that smoking is causally connected to cancer. It wasn’t always so clear, however. As late as 1994, tobacco executives felt comfortable testifying before congress under oath that nicotine was not addictive, and anti-tobacco lawsuits didn’t have a single win until (I think) the 90’s as well. And yet my father reports that the incidence of smoking dropped precipitously among the scientists / engineers in his acquaintance in the 1950’s, about forty years earlier. Clearly, it’s sometimes possible to make correct decisions even in the presence of uncertainty.
And finally, on politics: I’m now understanding that you mean the term as a neutral, value-free description of the negotiation of policies, without negative implication or connotation. This is a bit different from colloquial English, where it is a bit of a loaded term. Just as a datapoint from a reader, let me say that, in the context of this paper, singling out advocacy of one particular position, but not the the other, as “political” came across as an accusation, with implicit undertones of wrong-doing or bad faith. The discussions elsewhere in the blog about the “politicization” of the IPCC had a similar tone, in my reading. I’m now understanding that this reading is incorrect, and not what you meant at all. Still, as you work together with other policy advocates towards developing consensus on selections from the buffet of policies, you may wish to check that the tone of your writing is being perceived as you wish it to be.
Thanks again, and I do plan to check out your viewpoints on hurricane mitigation.
November 22nd, 2005 at 6:17 pm
So here’s another fine mess I’ve gotten myself into…
Concerning climate change denial, does anyone who reads and participates in this forum actually believe that climate change denial does not exist? If so, then what do you call the following? (From http://www.globalwarming.org/article.php?uid=65. This is the very first web site that comes up when you Google “global warming”.)
“Are humans causing the climate to change?
98% of total global greenhouse gas emissions are natural (mostly water vapor); only 2% are from man-made sources.
By most accounts, man-made emissions have had no more than a minuscule impact on the climate.”
By “MOST ACCOUNTS”? Are these people serious?
More important, if this isn’t denial, then could some one please tell me what it is. (I can think of an alternative: a “lie”.)
Concerning Roger’s initial response to my challenge, you are right. I am wrong. Of course — the goal is to avoid societal impacts. I don’t know what I was thinking. Perhaps I’ve been away from Prometheus for too long…
What I meant is do you think reducing greenhouse gas emissions is a necessary policy response to climate change? If you do, how should we frame the case for taking action on that basis — for the public, and for policy makers who are resistant to taking such action?
November 22nd, 2005 at 8:28 pm
Come on Tom. You have posted a FIVE year old quote from a questionable website that is certainly anything but scientific. You would never have referenced such garbage in any published paper. And Google’s rankings are not a measure of respectability.
I repeat and I believe that everyone else who visits this site would second, ” among climate informed people, (with the exception of FS), there is no such thing as a denier. Michaels, Lindzen, Christy, etc.,etc. all recognize that the earth is warming and that humans are involved. Beyond this is where the arguments start.
Oh I wish journalists could open their minds to the legitimacy of the climate change dispute. When they finally do, then I predict that we will be on the road to something better.
November 22nd, 2005 at 9:11 pm
Allow me to return to Prof. Pielke’s statement:
“Even a 100% level of evidence of a connection between global warming and hurricanes is unlikely to radically change the ORDERING of policies most likely to be effective with respect to addressing future hurricane damages. This is because of the overwhelming influence of growing societal vulnerability to storm impacts.”
I emphasized ORDERING, because I think it is very important. I take this to mean that there are short term policies which can (should) be put in place, but are in no way related to or driven by any possible connection between hurricances and global warming. With this I agree, both as a practical matter (it will happen that way) and a moral and economic one (it should happen that way). OTOH, assuming a 100% connection between hurricanes and anthropic (I added a word) global warming, actions which over the long term are likely to diminish hurricane damage through their diminution of anthropically driven global warming, would come later. However, if there were a 100% demonstration of no connection, these actions would simply not be taken. Thus I have to reject the first sentence in Prof. Pielke’s statement.
The second is completely valid, but vapid. We know that hurricanes are major bad and given population shifts which make them even more dangerous, something is going to be done in some order.
November 22nd, 2005 at 11:47 pm
For Tom and Paul, we have
http://www.globalwarming.org/article.php?uid=889
http://www.globalwarming.org/article.php?uid=891
from 2005 on the same site
and of course the evergreen
http://www.john-daly.com/
Yes Virginia, the nile is not just a four year old river in Egypt.
November 23rd, 2005 at 12:49 am
Tom Yulsman wrote:
“More important, if this isn’t denial, then could some one please tell me what it is. (I can think of an alternative: a “lie”.)”
He was referencing the ‘Cooler Heads’ website, which, in my opinion, decided to fight fire with fire. In other words, they employed the same type of argumentation that the other side uses constantly. For example, while the site was posted in 2000, their claim of ’slightly cooling’ satellite temperatures consisted of 18 years of a 21 year record. Until 1998, the satellites DID indicate a slight cooling trend, so that was the period they decided to reference.
They do not deny climate change at all, indicating in their very first point that surface temperatures appear to have warmed about .5 degrees C in the last century. They also cleverly and correctly indicate that the human influence on climate has been very small, which, of course, is absolutely true when compared to the total concept of climate! Also, the amount of the human contribution to greenhouse gases is very low, just like they indicate, but the argument on the other side has never been that human contributions to greenhouse gases in the Earth’s Atmosphere is a significant percentage of the total.
What they have done is simply taken factual information and phrased it in a way that leads the reader to believe what the authors intend.
What is so amusing to me is that you find this practice a gross misrepresentation of the facts on the Cooler Heads site, but fail to recognize the same methods used blatantly on most sites warning of impending doom! (I assume this because of your previous use of the phrase ‘climate change deniers’ as a reference to all those who question the validity and ‘robustness’ of the IPCC scenarios. Such mischarachterizations are rampant on those sites.) The skeptics have been demonized for quite some time with such phrases, as well as unfounded accustations of corruption and of miniscule numbers (i.e. there are only 5 skeptics), none of it true. Data, or even antecdotes, that supports the AGW theory are trumpeted as proof, while data that contradicts the theory is simply ignored. I have watched it for 15 years.
While most of this has been taking place in the media and with environmental organiztions, outside of scientific circles, there have been some interesting trends in otherwise fine papers over the last decade. Reports on past climates, from extended droughts in the Southwest US to recent cooling in the Antarctic, presented reasonable evidence in the body of the works, but in the conclusion expressed some opinion about future conditions due to man-made global warming, even though there was nothing in their work related to or even implying future climate change. During the 90s, it seemed to be some kind of ‘future grant’ insurance policy for all contributors of Climate Papers, but it gave the impression that everyone excepted the the company line on climate change.
My whole point of this diatribe is that persuasive techniques that are not representative of the body of scientific evidence have been thrust at the public for 15 years, with very little of it coming from skeptics. So much of this has come from climate change catastrophists that the public is actually getting pretty numb to it all. Even Europeans are starting to have doubts, which is amazing considering that most have never heard a dissenting view point.
If you wish to critize ‘Cooler Heads’, that is fine with me, but please include the myriad of AGW doom and gloom web sites that are even more guilty of selective arguments, or as you call it… lying!
November 23rd, 2005 at 6:03 am
Eli Rabett-
Thanks for your comment. You write, “However, if there were a 100% demonstration of no connection, these actions would simply not be taken.”
In my view, the case for climate mitigation does not rest significantly on preventing future hurricane damages. That is, whether there is a 100% connection or 100% no connection, the case for climate mitigation is strong in either situation.
November 23rd, 2005 at 9:23 am
Tom- Thanks for the clarification. This question deserves a post of its own for a reply, but the quick answer is: Yes. Yes, I think that climate mitigation (i.e., reducing GHGs) makes sense, the real question is how to do it successfully. David Victor and Ron Brunner have written some valuable perspectives on this. I will make a point to say more about this before too long. Thanks!
November 26th, 2005 at 12:25 pm
This article in the Washington Post is well done:
http://www.washingtonpost.com/wp-dyn/content/article/2005/11/26/AR2005112600355.html
November 28th, 2005 at 7:34 pm
Roger, I am not sure that your reply on the 23rd is so easy to reconcile with the statement that I commented on, however, it contains within itself a contradiction. To start, it would be interesting to know what you consider as strong enough evidence that climate mitigation is needed, and what resources are commensurate with the threat.
Now, starting from the point that at present you do not believe that any link has been shown between climate change and hurricane intensity and frequency, assume that a strong link was shown to a high degree of certainty. How much additional potential damage would have to be shown likely for additional efforts to be made limiting anthropic climate change?
December 3rd, 2005 at 2:25 pm
Dr. Pielke and Eli Rabett,
I am an outsider and a student, so correct me where I go wrong. Even if there was an established 100% link between hurricane intensity and frequency, it seems that the rise in potential damage from GHGs would still not enter our policy calculus, assuming we have some sort of reasonable discount rate. From my understanding, sea surface temperature rise will lag significantly behind atmospheric temperature rise. Accordingly, hurricane intensity will pose problems only after we have experienced the more imminent results of climate change (i.e. desertification, ablation of ice sheets, weakening of THC, disease).
As an aside, there seems to be an outpouring of discontent in climate change literature over media potrayals of the climate policy debate. Everyone, including Dilling, points to the problem of the media giving equal time to climate change action activists and climate change deniers. I won’t present my opinion on this, however, it seems that it is detrimental to the credibility of climate change activists when they augment their case with things like the link between hurricane intensity and global warming. NOAA just refutes the point, and it makes for a great story. If climate activists would stick to evidence that is widely accepted while making their point, the point-counter-point style of climate coverage will eventually fade. In this way, I think your paper, Dr. Pielke, serves the climate activists well. The debate shouldn’t be between ‘cooler heads’ and climage hot heads, it should be levelheaded.
December 15th, 2005 at 2:39 am
Considerations for Mr. Bozmoski:
Your dismissal of the link between global warming and hurricane intensity is a bit premature. You write, “It is detrimental to the credibility of climate change activists when they augment their case with things like the link between hurricane intensity and global warming.” From our understanding, there is admittedly a lag between global atmospheric temperatures and SSTs. However, there has already been an increase in SST of 0.5 degrees C, showing that irregardless of this lag, ocean temperatures are an issue.
Though we agree that various oscillations, in particular the El Nino-Southern Oscillation, are the major factors of varying hurricane activity, you cannot claim that there is absolutely no room for global warming. Kerry Emanuel’s recent publication in Nature is telling proof that there is some correlation. Granted, the Washington Post highlights some of the flaws of Emanuel’s research (e.g. data collection). However, there is no denying that increases in hurricane intensity have roughly correlated to rising global temperatures over the past 30 years. You may wish to refer to his graphs.
If Emanuel, who once disbelieved the link between global warming and hurricanes, came to these conclusions, we cannot easily dismiss this possible link.
January 7th, 2007 at 12:37 pm
Roger,
The link to the article doesn’t quite work. Could you provide a link (or email me the article?)
Thanks!