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January 17, 2005

Chris Landsea Leaves IPCC

Posted to Author: Others | Climate Change | Science Policy: General

This is an open letter to the community from Chris Landsea.

Dear colleagues,

After some prolonged deliberation, I have decided to withdraw from participating in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). I am withdrawing because I have come to view the part of the IPCC to which my expertise is relevant as having become politicized. In addition, when I have raised my concerns to the IPCC leadership, their response was simply to dismiss my concerns.

With this open letter to the community, I wish to explain the basis for my decision and bring awareness to what I view as a problem in the IPCC process. The IPCC is a group of climate researchers from around the world that every few years summarize how climate is changing and how it may be altered in the future due to manmade global warming. I had served both as an author for the Observations chapter and a Reviewer for the 2nd Assessment Report in 1995 and the 3rd Assessment Report in 2001, primarily on the topic of tropical cyclones (hurricanes and typhoons). My work on hurricanes, and tropical cyclones more generally, has been widely cited by the IPCC. For the upcoming AR4, I was asked several weeks ago by the Observations chapter Lead Author - Dr. Kevin Trenberth - to provide the writeup for Atlantic hurricanes. As I had in the past, I agreed to assist the IPCC in what I thought was to be an important, and politically-neutral determination of what is happening with our climate.

Shortly after Dr. Trenberth requested that I draft the Atlantic hurricane section for the AR4's Observations chapter, Dr. Trenberth participated in a press conference organized by scientists at Harvard on the topic "Experts to warn global warming likely to continue spurring more outbreaks of intense hurricane activity" along with other media interviews on the topic. The result of this media interaction was widespread coverage that directly connected the very busy 2004 Atlantic hurricane season as being caused by anthropogenic greenhouse gas warming occurring today. Listening to and reading transcripts of this press conference and media interviews, it is apparent that Dr. Trenberth was being accurately quoted and summarized in such statements and was not being misrepresented in the media. These media sessions have potential to result in a widespread perception that global warming has made recent hurricane activity much more severe.

I found it a bit perplexing that the participants in the Harvard press conference had come to the conclusion that global warming was impacting hurricane activity today. To my knowledge, none of the participants in that press conference had performed any research on hurricane variability, nor were they reporting on any new work in the field. All previous and current research in the area of hurricane variability has shown no reliable, long-term trend up in the frequency or intensity of tropical cyclones, either in the Atlantic or any other basin. The IPCC assessments in 1995 and 2001 also concluded that there was no global warming signal found in the hurricane record.

Moreover, the evidence is quite strong and supported by the most recent credible studies that any impact in the future from global warming upon hurricane will likely be quite small. The latest results from the Geophysical Fluid Dynamics Laboratory (Knutson and Tuleya, Journal of Climate, 2004) suggest that by around 2080, hurricanes may have winds and rainfall about 5% more intense than today. It has been proposed that even this tiny change may be an exaggeration as to what may happen by the end of the 21st Century (Michaels, Knappenberger, and Landsea, Journal of Climate, 2005, submitted).

It is beyond me why my colleagues would utilize the media to push an unsupported agenda that recent hurricane activity has been due to global warming. Given Dr. Trenberth’s role as the IPCC’s Lead Author responsible for preparing the text on hurricanes, his public statements so far outside of current scientific understanding led me to concern that it would be very difficult for the IPCC process to proceed objectively with regards to the assessment on hurricane activity. My view is that when people identify themselves as being associated with the IPCC and then make pronouncements far outside current scientific understandings that this will harm the credibility of climate change science and will in the longer term diminish our role in public policy.

My concerns go beyond the actions of Dr. Trenberth and his colleagues to how he and other IPCC officials responded to my concerns. I did caution Dr. Trenberth before the media event and provided him a summary of the current understanding within the hurricane research community. I was disappointed when the IPCC leadership dismissed my concerns when I brought up the misrepresentation of climate science while invoking the authority of the IPCC. Specifically, the IPCC leadership said that Dr. Trenberth was speaking as an individual even though he was introduced in the press conference as an IPCC lead author; I was told that that the media was exaggerating or misrepresenting his words, even though the audio from the press conference and interview tells a different story (available on the web directly); and that Dr. Trenberth was accurately reflecting conclusions from the TAR, even though it is quite clear that the TAR stated that there was no connection between global warming and hurricane activity. The IPCC leadership saw nothing to be concerned with in Dr. Trenberth's unfounded pronouncements to the media, despite his supposedly impartial important role that he must undertake as a Lead Author on the upcoming AR4.

It is certainly true that "individual scientists can do what they wish in their own rights", as one of the folks in the IPCC leadership suggested. Differing conclusions and robust debates are certainly crucial to progress in climate science. However, this case is not an honest scientific discussion conducted at a meeting of climate researchers. Instead, a scientist with an important role in the IPCC represented himself as a Lead Author for the IPCC has used that position to promulgate to the media and general public his own opinion that the busy 2004 hurricane season was caused by global warming, which is in direct opposition to research written in the field and is counter to conclusions in the TAR. This becomes problematic when I am then asked to provide the draft about observed hurricane activity variations for the AR4 with, ironically, Dr. Trenberth as the Lead Author for this chapter. Because of Dr. Trenberth's pronouncements, the IPCC process on our assessment of these crucial extreme events in our climate system has been subverted and compromised, its neutrality lost. While no one can "tell" scientists what to say or not say (nor am I suggesting that), the IPCC did select Dr. Trenberth as a Lead Author and entrusted to him to carry out this duty in a non-biased, neutral point of view. When scientists hold press conferences and speak with the media, much care is needed not to reflect poorly upon the IPCC. It is of more than passing interest to note that Dr. Trenberth, while eager to share his views on global warming and hurricanes with the media, declined to do so at the Climate Variability and Change Conference in January where he made several presentations. Perhaps he was concerned that such speculation - though worthy in his mind of public pronouncements – would not stand up to the scrutiny of fellow climate scientists.

I personally cannot in good faith continue to contribute to a process that I view as both being motivated by pre-conceived agendas and being scientifically unsound. As the IPCC leadership has seen no wrong in Dr. Trenberth's actions and have retained him as a Lead Author for the AR4, I have decided to no longer participate in the IPCC AR4.

Sincerely, Chris Landsea

Attached are the correspondence between myself and key members of the IPCC FAR, Download file.

Posted on January 17, 2005 11:39 AM


Well, thats rather interesting. I will watch to see what the fallout is. My immeadiate reaction is that CL is being rather premature. Had he waited a bit longer and pulled out because people had been interfering with his text, trying to "sex it up" or whatever, that would have been quite strong. As it is he is pulling out because he feels worried that someone might, even though no-one has.

Posted by: William Connolley at January 17, 2005 02:10 PM

Good, I'm glad he's leaving. We don't need to
read climatology papers to know that climate is
changing far faster than the simulation have
been predicting.

Posted by: Thomas Lee Elifritz at January 17, 2005 02:52 PM

It would seem stronger, to me, to remain and fight. Surely no one is going to 'fire' him over this flap - staying and exposing any bias in the process would do a lot more good.

It will be interesting to see how this gets trumpeted, and the Crumb Trail trackback is the first clue - perhaps giving weight to the phrase 'making a picnic out of a crumb'.



Posted by: Dano at January 17, 2005 08:47 PM

This isn't a question of resigning when it would have the most impact. It's a question of ethics.
When the lead author of a scientific publication makes a public mis-statement of the science, it is incumbant on the co-authors to attempt a correction. Failing this (the IPCC board should have at least conducted a public flogging if not removed Dr. Tender from his position as lead author), there are few ethical options open other than resignation.

Posted by: Jim Kanuth at January 18, 2005 03:19 PM

I'm not defending Trenberth's actions, Jim.

I'm stating it would be stronger to stay, fight for publishing what you think is the latest finding, and directly refute a public pronouncement that you think is incorrect. Walking away doesn't correct the situation.

Perhaps Landsea does not have the experience or wherewithal to fight - I do not know. Fighting for what one thinks is right, however, is what I would do.

This incident appears to validate my understanding of Roger's view that scientists should stay out of the fray. In my view, the horse is out of the barn and in a world where we are competing for scarcer resources, we need to find a way to ensure bias doesn't creep into conclusions.



Posted by: Dano at January 18, 2005 05:48 PM


Thanks much for your comments. Just a quick clarification -- it is an mischaracterization to suggest that I recommend that scientists "stay out of the fray." In fact, scientists really have no option but to be part of the fray, whether they like it or not (see the recent exhcanges on this site with the RealClimate folks). But scientists do have choices about how they participate in the fray. I have urged scientists to recognize these choices, and their consequences. See, e.g., the discussion in this paper:

Pielke, Jr., R. A., 2002: Policy, politics and perspective. Nature 416:368.

Thanks again for your comments.

Posted by: Roger Pielke, Jr. at January 18, 2005 08:24 PM

My apologies Roger. I seem to have forgotten that piece of yours. Keep up the good work, sir.



Posted by: Dano at January 18, 2005 10:30 PM

Having read the comments and heard the introduction of and by Trenberth, I have to agree that Landsea is overreacting. Indeed Trenberth should have said that this was his own opinion, as that confused the media into telling their audience that it was the opinion of the IPCC, which it was not. But it is quite normal that one is introduced by his affiliations and previous work...

But it questions the supervising role of the IPCC, by pointing a scientist with a strong (caused-by-human-induced-GW) point of view as the lead author. A more neutral scientist would have been better to balance the different opinions...

Posted by: Ferdinand Engelbeen at January 19, 2005 07:18 AM

Unfortunately Trenberth's comments are consistent with what I have seen from him and a few others in the leadership of atmospheric science in this country. They appear to be afraid to give any plausibility to any characterization of climate change as less than catastrophic. They do not accept any shades of gray. As someone who has worked on and been humbled by the complexity and lack of predictability in the atmospheric and ocean system, I am consistently amazed at how sure they seem to be. While they may justify their positions as being good for our science - in the end such foolish pronouncements that are not scientifically warranted will make our science the laughing stock of real scientists.

Posted by: Richard McNider at January 19, 2005 08:14 AM

Note that Dr. Landsea said nothing to indicate that he disagrees with the bulk of Global Warming science - only with the overstepping of an individual in linking Global Warming with hurricane occurrence. Dr. Landsea appears to have the highest level of integrity - and it may be that he may or may not agree with Global Warming Theory on the whole, but does not feel qualified to make a positive or negative statement about it.

Which puts him miles ahead of most of the pundits out there who are willing to attack general scientific consensus with far less understanding of the theory and data than he.

Posted by: Phil at January 19, 2005 03:06 PM

I don't think Chris Landsea is overreacting. I think he is making the point that science is about doing the research and reporting on it. Someone in Trenberth's position does not have the luxury of venting his unsupported opinion in the name of the group. He is their representative and as such doesn't do his own rogue elephant thing.

Posted by: NileQueen at January 20, 2005 08:47 PM

Sorry Landsea decided to leave. Science is constructed by scientists, and we know almost nothing. Events have been demonstrating how poor is our understanding of climate changes origins.
One thing is undeniable, the atmospheric chemistry is absolutely different from what it was in the past, due to anthropic influence. This can lead to absolutely unexpected events. No model can take in account all and every volatile substances and particles. Many factors are definitively not known. Seemingly so big, our system is thermodinamically a laboratory flask.. Nothing can be discarded only because we think things are being explained by our hypotheses. Everyday scientists discover how wrong they are..(we are)

Posted by: Lundz at January 20, 2005 09:32 PM

Applause for Landsea. Neither a PR man nor a politician, he simply writes an open letter and withdraws from something he doesn't feel good about. It's not a big deal, it seems, from his point of view: he's concerned with being a scientist as he understands the term. I think our shock and awe comes because we're so unused to anyone acting this way, but I think it's admirable precisely because it isn't a big deal: we're used to Condaleeza Rice staying on and ultimately getting promoted; Landsea's high-definition standards are bewildering.

Posted by: Applauder Boy at January 20, 2005 11:51 PM

Something I've just seen pointed out by the eagle eye of ES at sci.env is that in his statement, Landsea references a forthcoming paper with Michaels. I don't understand how L can complain about Trenberth, and then associate himself, via publication, with someone like Michaels.

Posted by: William Connolley at January 21, 2005 12:12 PM

I would compare the IPCC to a great ship setting out on it's maiden voyage, full of arrogant belief in its unsinkable theory, and dismissing any suggestion of prudence or caution.
The name of this ship? - The Titanic.

History will show that Landsea has made entirely the right decision to abandon the ship.

Posted by: CW at January 22, 2005 01:58 AM

What's the difference between a scientist and a prostitute?

Not much, apparently.

"Evidence - we don't need no stinkin' evidence!"

Posted by: Captain America at January 23, 2005 12:50 PM

Man-made global warming is nothing more than a scam, based on flawed computer models and hidden agendas. When was the Earth's climate ever constant? On a geological timescale, the last ice age was yesterday, the next one arrives tomorrow, in between we have a warm period. In the past 740,000 years we have had 8 ice ages, each followed by 'global warming.'

Posted by: Paul Biggs at January 24, 2005 12:45 AM

To me it seemed that if he remained a part or IPCC he would be linked with people who are deliberately dishonest (Dr. Trenberth), and covering up for the dishonesty (IPCC). To continue to be a part of that would imply that he agrees with the dishonesty. In his letter, Dr. Landsea nowhere suggests that he has discontinued research or publication. He does not suggest that he has left the "fray," merely discontinued his association with dishonesty.

Posted by: Eric Skouson at January 24, 2005 09:16 AM

Please see Roger's
well-tempered follow-up article. And while there, I hope you will read the comment I posted to that. It would just as well apply here.

Posted by: Peter J. Wetzel at January 24, 2005 11:11 AM

Still getting up to speed with the mechanics of this blog. Here's the link for Roger's follow-up article. I attempted to use HTML to link to it, and was thwarted!

Posted by: Peter J. Wetzel at January 24, 2005 11:13 AM

It's pretty obvious to anyone who takes the time to do an even-handed examination of the matter that the projections for methane atmospheric concentrations, CO2 emissions and atmospheric concentrations, and resultant temperature increases in the IPCC Third Assessment Report are the greatest fraud in the history of environmental science:

It's time for the IPCC to stop lying. Of course, an *honest* assessment of potential global warming in the 21st century will mean that a whole lot less research money will be available. But enough is enough. This needs to stop before "environmental science" is considered to be an oxymoron.

Mark Bahner (environmental engineer)

Posted by: Mark Bahner at January 25, 2005 08:54 PM

Here's what Trenberth said:
"Human activities are changing the composition of the atmosphere and global warming is happening as a result," says Kevin Trenberth, head of the Climate Analysis Section at NCAR and a convening lead author of the 2007 IPCC report for the chapter on observed changes. "Global warming is manifested in many ways, some unexpected. Sea level has risen 1.25 inches in the past 10 years as a result of warming of the oceans and glacier melting. The environment in which hurricanes form is changing. The result was a hurricane in late March 2004 in the South Atlantic, off the coast of Brazil: the first and only such hurricane in that region. Several factors go into forming hurricanes and where they track. But the evidence strongly suggests more intense storms and risk of greater flooding events, so that the North Atlantic hurricane season of 2004 may well be a harbinger of the future."
This does not sound so different from what Landsea acknowedges in his letter to Trennberth.

Dan Kirk-Davidoff, Asst. Professor of Meteorology, U. Maryland.

Posted by: Daniel Kirk-Davidoff at January 31, 2005 10:00 AM

I think Dano is completely right. He does not make mistakes who does nothing, and Landsea has reserved this right from the moment he left. To remain and fight - would be definitely the right thing to do.

Posted by: Lola at March 29, 2005 03:58 PM

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