24 September 2010

IPCC on Extreme Events: Getting Better but Still Not Great

Yesterday, Michael Oppenheimer from Princeton University and coordinating lead author of the IPCC special report titled Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation, provided a briefing to the Select Committee on Energy Independence and Global Warming of the US House of Representatives (here in PDF).  Oppenheimer's testimony was far more in line with the state of the science on this subject than have been recent IPCC reports and press releases, but remains slanted and focused on advocating action on emissions.

Oppenheimer states:
So-called “joint attribution” the assignment of cause for the damaging outcomes of such extremes, such as wildfires or human mortality occurring during hot and dry spells, is a relatively new field, and it remains difficult to associate recent increases in most such impacts directly with greenhouse gas emissions, but indirect evidence is strongly suggestive of such a link in many cases.
This is a convoluted way of simply saying that the present state of the science does not support claims of attribution.  In suggesting that this is a "new" field he notably avoids discussing a large body of literature such as on tropical cyclones (in the US, Australia, China, India, Latin America, etc.), floods, European storms, Australian bushfires, etc. where peer reviewed work has explained damage trends solely in terms of increasing societal vulnerability.  Why is it so hard for IPCC authors to acknowledge any of this literature?  But, even so, I give Opeenheimer some credit for moving in the right direction.

Oppenheimer's conclusion acknowledges the importance of societal factors in driving disasters, but then completely ignores adaptation (which he does mention elsewhere in the presentation), which indicates to me that the desire to advocate among IPCC leaders will be a habit hard to control:
Finally, while extreme events are generally a physical phenomenon, circumstances where such events translate into disasters, like Hurricane Katrina or the great European heat wave of 2003, depend in large measure on individual and societal anticipation, planning, and response capacity and implementation. In other words, disaster is partly a social phenomenon. In both of these episodes, the toll was much higher than was imagined possible before the events. Unfortunately, if history is a guide, such situations may become ever more common. Even as we learn to cope better with certain extreme events, the climate may change faster than we learn about it, and faster than our ability to implement what we have learned. The only remedy for such a situation is to act to slow the climate change by slowing greenhouse gas emissions.
Oppenheimer's statement is a move in the right direction, but it is highly selective, slanted and gives some misleading policy advice.  The reality is that actions today to reduce emissions will not have an discernible effects for many decades.  By not mentioning the time scale of the effects of mitigation and the relative role of mitigation and adaptation for addressing future losses (another literature not mentioned), Oppenheimer is arguably misleading.

If I had to give a grade to the presentation -- if the IPCC 2007 was an "F," then Oppenheimer gets a "C-."  The IPCC leadership still has a ways to go on the issue of extreme events.  Its extremes report is not due out for another year (remarkably), so they have lots of time to up their game.


Mark B. said...

"This is a convoluted way of simply saying that the present state of the science does not support claims of attribution."

More like a convoluted way of saying that the present state of the science does not support claims of attribution, but he's going to make the claim anyway.

This is classic science-speak in action. Another common example: 'I know that correlation is not causation, but in this case it is.' It's what happens when scientists know where they want to go, but they don't have enough gas to get there.

Laurens said...

As the review and further writing of that special report continues, I expect that IPCC will further move into the direction of acknowledging the evidence from the literature. My expectation is also that with increased attention to the process, authors will need to carefully consider all critical reviews, and include only statements supported by the scientific evidence.

sdcougar said...

I hope everyone reading Roger's grade report here will pass it on to there members of Congress.

And we also need to be sending article like this to the PBS Ombudsman and asking him "WHY" we NEVER hear anything like this on the PBS NewsHour.

Christopher J. Burton said...

It would be a welcome change if the IPCC were to report climate trends that are based on supportable hard data. They should be constrained from expressing any official theories or predictions with regard to our collective fate. The cost is too high to permit a body, such as the IPCC, with interest in only one side of the funding ledger to propose international solutions. The use of climate data for the purpose of predictions and adaptation should be a national responsibility. This will force the politicians and the scientists to develop plans that taxpayers can review and control without the sanction of an international climate club.

rjtklein said...

Hi Roger,

I haven't seen the briefing, so I don't know how Michael Oppenheimer was introduced, but I doubt he was meant to speak on behalf of the IPCC. I wouldn't therefore interpret his comments as coming from the IPCC.

However, he does create potential confusion by introducing himself as a coordinating lead author of two upcoming IPCC reports. I assume he did that to establish his credentials, just like he mentioned that he's a professor at Princeton. In principle there's nothing wrong with that, but obviously it can be misunderstood, and I think that's what happened here.

The IPCC procedures are very clear that reports that have not yet been adopted by the IPCC Plenary (i.e. the governments) contain only preliminary findings. The only way in which any IPCC work in progress (including the Special Report 'Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation', or SREX) is communicated to the 'outside world' is through the review process. That would be the place for you to judge whether or not the IPCC report is worth a C-, and to suggest how it can be improved towards a better mark.

Oppenheimer's comments are Oppenheimer's comments. And right now it's Oppenheimer's comments you're marking.

Roger Pielke, Jr. said...


Thanks for these comments.

This is obviously another place where the IPCC can tighten up its procedures. I assume that an IPCC CLA who introduces himself as such is speaking with the authority of the institution.

My critique is this not at all about the report, but rather about Oppenheimer's comments as a self-identified representative of the IPCC.

rjtklein said...

Thanks Roger. But in that case I'd say that the title of your blog post is slightly misleading...!

Roger Pielke, Jr. said...


Why misleading? As I said, I see Oppenheimer as speaking for the IPCC. Not the report specifically, but the IPCC as an institution.

rjtklein said...

-8- Roger

I don't see why you would see that. I think it's a stretch to interpret Oppenheimer's self-introduction as an IPCC author as his representing the IPCC.

Moreover, the findings he presents in his briefing are all from the Fourth Assessment Report (AR4). Anybody could present AR4 findings, because that report has been published. I know you regularly use AR4 findings in your talks, and so do I and many others. To present AR4 findings does not mean to represent the IPCC.

After introducing himself as an IPCC author, Oppenheimer could have avoided confusion by stating explicitly that he doesn't speak on behalf of the IPCC. He must be aware that it's easy to be misunderstood (which is what I think you did), and that the unfortunate polarisation over the IPCC means such misunderstandings could be interpreted as yet another weakness of the IPCC (e.g. your comment about IPCC procedures).

This really is a non-story. Oppenheimer gives a briefing, he mentions that he's an IPCC author, you interpret it as his representing the IPCC when it should be obvious (but obviously not obvious enough) that this is not the case. This non-story has nothing to do with the IPCC, yet the title of this post suggests otherwise.

Roger Pielke, Jr. said...


Yes, we'll just have to agree to disagree. When the CLA of an IPCC report is invited to present to the US Congress on the subject of the report, I think that it is safe to assume that the invitation was issued by virtue of his position.

If he wanted to express personal opinions outside that role, then it is his responsibility to explicitly say so. If those opinions are at odds with the evidence in the peer reviewed literature, then that raises other questions.

I interpret Oppenheimer as speaking as a representative of the IPCC.

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