Roger´s reaction concerning the article in Nature shows, how difficult it is to record correctly this complex debate. We did indeed use in Hohenkammer the definition of climate change as mentioned by Roger.

But then a similar thing happens to Roger, he doesn’t quote the Nature article carefully enough. He writes: “Nature cites Germanwatch as a group who has used attributed disaster losses to human-caused climate change”. But in the Nature article we read: “environmental groups are already using the rise in extreme weather events [!] to help their campaigns about climate change. For example, Germanwatch, an environmental and developmental watchdog group, has used the Munich Re data to compile a ranking of the countries most badly affected by weatherrelated disasters in 2004.”

Nature doesn’t cite Germanwatch as a group who has used attributed disaster losses [!] to human-caused climate change, but as a group “using the rise in extreme weather events to help their campaigns about climate change”.

I think that there is good reason to do so (while the climate risk index has a different intention, see last section) and that balance of evidence has shifted during the last two years.

Munich Re has presented again data, that the trend of the global numbers of great natural catastrophes since 1950 shows a steep increase in weather related disasters from about one event in the 1950s to about 5 in recent decades while geophysically-caused disasters (earthquakes, tsunamis, volcano eruptions) have increased from one to less than 2 in the same time. In Hohenkammer Munich Re has argued, that societal factors or data quality could hardly affect the idendified trend in numbers of weather related great natural catastrophes, nearly all great disasters of the 90s would have been great disasters already during the 50s. (This is of course only true for the the numbers of great disasters, not for related damages. There societal factors are dominant.) The recommendation to create an open-source disaster database according to agreed upon standards is one of the very constructive results of the Hohenkammer workshop, which has the potential to clarify some of the open issues.
We discussed some new scientific developments in Hohenkammer: Regarding changing hurricane activity levels several studies document over the past decades a trend of more intense storms (in terms of peak intensity and portion of lifetime covered by very high wind speeds). These shifts are associated with positive trends in tropical sea surface temperatures – globally some 0.5 °C since 1970 – as the key parameter (Emanuel, 2005a and 2005b; Webster et al., 2005; Hoyos et al., 2006). There are recently published studies attributing trends in sea surface temperatures since 1970 to anthropogenic climate change (e. g. Barnett et al., 2005). Given SST as the key parameter for tropical cyclone activity levels evidence was presented for storm intensity shifts driven by climate change implying anthropogenic GHG emissions forcing (Emanuel 2005a and 2005b, Hoyos et al. 2006).

But we also saw in Hohenkammer that there is still reason for debate about these results. So the consensus was: “Although there are peer reviewed papers indicating trends in storms and floods there is still scientific debate over the attribution to anthropogenic climate change or natural climate variability. There is also concern over geophysical data quality. (5)”

The debate doesn’t seem to be, whether there exists a link between global warming and hurricane intensity at all, but whether it is really so unexpectedly strong (four to six times stronger than expected) as the observations from Emanuel, Webster, Sriver and Huver (2006) suggest. The open question is now, whether to count the anomalous strengthening against observations (natural cyle, data quality), or to count it against theory. Some like Roger count it against the observations, data quality is the central point of this debate. Differently Emanuel: „I count it against the theory, although I helped to develop the theory” (Emanuel in Kerry, 2006). The debate isn´t over yet. So for the moment I also support what the WTO (2006) says: “Given time the problem of causes and attribution of the events of 2004–2005 will be discussed and argued in the refereed scientific literature. Prior to this happening it is not possible to make any authoritative comment.”

I also agree with the consensus statement about the difficulties to quantify the attribution of climate change to the disaster loss record. Even if there is already today a relevant impact of global warming on damage trends, it will not be easy to quantify it. Because of issues related to data quality, the stochastic nature of extreme event impacts, length of time series, and various societal factors present in the disaster loss record, it is still not possible to determine the portion of the increase in damages that might be attributed to climate change due to GHG emissions. This implies, that it is likely or at least possible that there is a portion of damages that might be attributed to anthropogene climate change. But it was also clear in the discussions of Hohenkammer, that „analyses of long-term records of disaster losses indicate that societal change and economic development are the principal factors responsible for the documented increasing losses to date.” (8).

This is the situation to date. But in the future the role of climate change might increase. The current evidence suggests that
a) hurricanes tend to become more destructive as ocean temperatures rise,
and
b) an unchecked rise in greenhouse gas concentrations will very likely increase ocean temperature further, ultimately overwhelming any natural oscillations. Scenarios for future global warming show tropical SST rising by a few degrees, not just tenths of degree (Rahmstorf et al. 2005).

There is also some plausibility behind the claim, that the now visible extension of the hurricane season and the hurricanes in new, not prepared regions, will have an impact on disaster trends.

It is a logical consequence that, if there will be more extreme events and/or these extreme events will increase in intensity losses will also increase. In general the increase in losses is associated linearly with the number of events (2 events mean 2-times the losses of one event) but nonlinearly with the intensity increase (e.g. for windstorms losses are a function of the square or cube of the wind speed).

So for the future I think it is plausible to expect a far stronger impact of global warming on damage records. It might even happen, that in the future we will interpret the last two extreme hurricane years as markers for a tipping point, as the beginning of a non linear shift in hurricane patterns (numbers, intensity, regional spread, longer seasons). But it is also possible that we will interpret these years just as two exceptional years, not indicating a new trend. Only two years ago there was hardly any evidence to suggest the possibility of a tipping point. So it’s by far too early to make this claim with certainty.

For the near future, issues related to data quality, the stochastic nature of extreme event impacts, length of time series, and various societal factors present in the disaster loss record, are expected to persist, making it unlikely that the quantitative link (attribution) of trends in storm and flood losses to climate changes related to GHG emissions will be answered unequivocally.
Hohenkammer has shown, that there is more consensus than many expected. But it has also shown, that for many debates we shouldn’t expect quick decisive results. Data still can be used to support different hypotheses. Politics, insurance, investment sector and others nevertheless have to act under uncertainty. It would be very interesting to use Bayesian Logic as a means of quantifying uncertainty. E.g. Carlo Jäger and his team from PIK, Potsdam, work with this method.
Based on probability theory, the Bayesian theorem defines a rule for refining a hypothesis by factoring in additional evidence and background information, and leads to a number representing the degree of probability that the hypothesis is true. Each year we could then see how reality changes the probability of different hypotheses. This would be a suggestion for the next constructive steps in this important debate.

I’m glad,that in Hohenkammer there was clear consensus to act and not to delay action – both in the fields of mitigation and adaptation. Preventative anticipation seems to be a wise strategy facing plausible but uncertain worst case scenarios. The main intention of the Germanwatch climate risk index is to raise political awareness for adaptation, mainly in relation to developing countries. Some of the white papers for Hohenkammer came to the same result as the index, that the impact of extreme weather events [...] varies between the developing and the developed world. While the developed world sees the highest absolute direct economic losses from weather extremes, the largest numbers of casualties and affected people occur in poor communities. And as the white paper from Zapata-Marti the index also shows, that if disaster losses are expressed as a percentage of GDP, developing countries are also more affected in economic terms. Even more if numbers are corrected for purchasing power parity (PPP). For least developed nations which are most vulnerable to weather extremes, adaptation is the main climate challenge – adaptation both to climate variability and climate change. (An energy efficiency and renewable energy strategy can also make a lot of sense for many of them, but primarily to create access to energy and to prevent a new debt crisis.)

Christoph Bals

“We will amend the online version of the story today with an asterisked paragraph at the bottom, reading:

*Roger Pielke Jr. has noted on his blog, Prometheus [link here], that his quote to Nature’s reporter read, in its entirety: “Clearly since 1970 climate change (i.e., defined as by the IPCC to include all sources of change) has shaped the disaster loss record.” Pielke further notes that the terms “climate change” and “global warming” are not interchangeable. Nature regrets the confusion. – Eds”

Thanks Nature, well done!

I’d like to plead temporary insanity–and cursory reading–for my comment.

I don’t know why I would defend a reporter from Nature, as I consider Nature and Science (and even shockingly and disgustingly, “Scientific” American) to have long since abandoned proper scientific skepticism on global warming. (How is it possible that Nature and Science have not long since denounced the IPCC TAR’s “projections” as unfalsifiable pseudoscientific rubbish? But I digress.)

I think my comments were motivated (in addition to the temporary insanity and cursory reading) by my awareness of the fact that, even though you constantly point out important differences in possible definitions of “climate change” (e.g. between the IPCC and FCCC), most people simply don’t have the time to keep such things straight.

Now that sanity has been restored, and more thought has been given to the matter, I completely agree that the quote shouldn’t have been changed.

In fact, I’ll now swing around to the other side, and recommend that you fire off a short letter to the Editors of Nature pointing out how your quote was manipulated (without even the fig leaf of an ellipsis! ), and how the manipulation essentially implies the exact opposite of what you intended.

If the Editors of Nature are truly worth their salt, they’d definitely publish such a letter, post haste (and with an apology for the error). But as far as what they’ll actually do, I’ll stick with the “Good luck (you’ll need it).”

Best wishes,
Mark

P.S. Speaking of the IPCC, when the AR4 comes out with pseudoscientific “projections” remarkably similar to the TAR, that would be a great policy issue for Prometheus. After all, you yourself have (correctly) labeled the temperature “projections” as the “central conclusion” of the IPCC TAR:

http://sciencepolicy.colorado.edu/moveabletype/mt-comments.cgi?entry_id=784

P.P.S. But I digress…

Thanks, but the Nature reporter has often covered climate change, my refernce to the IPCC definition should not have confused.

Even so, my quote should not have been altered without first checking with me.

You previously wrote, “Clearly since 1970 climate change (i.e., defined as by the IPCC to include all sources of change) has shaped the disaster loss record.”

Now you write, “Given that the Nature article equates ‘climate change’ with global warming, this completely changes the meaning of my sentence.”

I think I understand both your concerns and your true meanings. But I think you’re dreaming if you expect reporters–even “science reporters”–to follow such nuance.

For example, “climate change” can mean:

1) anthropogenic global warming,
2) natural global warming,
3) some combination of 1 and 2,
4) anthropogenic regional warming,
5) natural regional warming,
6) some combination of 4 and 5,
7) anthropogenic global cooling, natural global cooling,
9) some combination of 7 and 8,
10) anthropogenic regional cooling,
11) natural regional cooling,
12) some combination of 10 and 11.

And that’s merely what I can think of off the top of my head.

And even “global warming” can be:

1) anthropogenic,
2) natural, or
3) some combination of the two.

Is it any wonder even objective people get confused?

I think a better way to make your first statement would have been, “Clearly since 1970 climate change (i.e., regional or global change, whether natural, anthropogenic, or a combination of the two) has shaped the disaster loss record.”

Good luck (you’ll need it),
Mark

P.S. Of course, my statement is based on the assumption that the IPCC includes both regional and global climate change as “climate change.” I’m sure you know, but I’m too lazy to even figure out whether that’s actually true.

“Clearly, since 1970 climate change has shaped the disaster loss record.”

Here is what I wrote in my email:

“Clearly since 1970 climate change (i.e., defined as by the IPCC to include all sources of change) has shaped the disaster loss record.”

Given that the Nature article equates “climate change” with global warming, this completely changes the meaning of my sentence.

I should have been asked if my statement was to be altered.

———- Forwarded message ———-
Date: Thu, 1 Jun 2006 07:52:58 -0600 (MDT)
From: Pielke Roger A
To: “Schiermeier, Quirin”
Subject: RE: Request from Nature

Quirin-

>
> Has this workshop helped in any way settle the
> issue, or is the
> dissent
> on the wane?

The workshop helped to clarify areas of agreement and areas where further research is needed. Among the most significant areas of agreement is that disaster damage is not the place to look for early indications of climate change, direct climate metrics are better sources for this information.

Agreement that attribution of trends in increasing disasters to climate change resulting from greenhouse gases cannot be made at present or for the near future does not mean that a link does not exist, but rather than science cannot today make this linkage. Consequently policy making should not depend upon such attribution (as does adaptation provisions under the FCCC) and policy advocates should exercise extreme caution in using disaster losses to justify climate mitigation, lest they go beyond what science can support. There are of course better and more immediate justifications for mitigation than addressing disaster losses in the near term.

> Are you personally more convinced now that at
> least a portion of the
> losses can (or must) be attributed to climate
> change?

Yes. Clearly since 1970 climate change (i.e., defined as by the IPCC to include all sources of change) has shaped the disaster loss record. One only need to see the Atlantic hurricane loss record to see that this is obvious. However, when one goes further back into time, I am less convinced that there has been an overall increase in losses once societal factors are considered. The attribution issue, as we concluded, remains clouded.

Irrespective of different views on the role of climate, which will continue to be a focus of research attention, there is overwhelming evidence that the vast majority of the increase in disaster losses is due to societal factors, and this wll continue. And this understanding if robust enough to motivate additional energy in risk mitigation efforts.

Probably more than you want, so let me know if you would like to follow up!

Thanks!

Roger