Interview with Hans von Storch by Daniel Lingenhöhl

Published in German in Spectrumdirekt and Zeit online on 3 December 2009

Translated by Marcel Hendrickx, Brussels

Mr von Storch, soon the world climate conference in Copenhagen will start. Some of your colleagues took this as an opportunity to publish a drastic diagnosis according to which climate change may be faster and more severe than previously thought. Is the climate situation really that bad?

 

The situation is in any case serious. But in this report it is suggested that all various hypotheses would be already known with certainty, which is not the case. My main methodological critique is directed towards relatively short time periods, conclusions about changes on much longer time periods. A single decade is not long enough to draw conclusions about long-term climate evolution.

What are then the relevant time periods?

To draw valid conclusions one needs at least 30 years, probably more. Climate changes are caused partially by greenhouse gases and partially by natural fluctuations - and these have time spans of a few decades. That is how we explain the current phase in which there is no apparent increase in warming. This stagnation, as some call it, is thus not worrying at all as such episodes are a climatically recurrent phenomenon. It should therefore be a fundamental principle in climate research not to exploit change derived from too short time series.

A further critical point is the "homogeneity" of the data: we need numbers that are comparable over the years. We can not easily switch between different sources. That however was done at least once with the data of the Climatic Research Unit (CRU) of the University of East Anglia as has recently been made public - the so called 'trick'. Trick means that several data sets are blended and their signals combined in such a way that they obtain the desired result.

The Copenhagen Diagnosis mentions for example a rise of the sea-level about 1 to 2 meters: a number that originates from the Potsdam-Institute for Climate Research (PIK). There exist a substantial number of diverging opinions that assume a less drastic rise. But these are not mentioned in the communication. The whole thing has the smack of a for political purposes dramatized presentation.

Moreover it seems that debate on climate protection has become more acrimonious in recent years: is this an expression of the desperation of science that not enough is being done?

That is right. I would appreciate if you would not say of ‘the science', but 'of alarmist scientists'. The public opinion gets the impression that everything the PIK says is equivalent with what the science says. The PIK does not speak for everyone, it speaks only for itself - even when its opinions and interpretations dominate the media. Anyhow, the public opinion realizes more and more that the PIK represents only a part of the researchers.

This is exemplified by the Copenhagen Diagnosis where only a few scientists are present. And these make their diagnosis for political purposes. Scientific statements should not be political; they should describe and explain the current climate changes.

A few year ago, my colleague Nico Stehr and I have already deplored that more and more statements are being sharpened too keep the dramatics. On the one hand that is understandable because the media need this dramatic to tell their story. When you keep telling the same story people stop listening. Therefore many statements are exaggerated a little bit each time. But in the end it does more harm than good. We see this again with the Copenhagen Diagnosis: the PIK has tightened the screws a little bit again and consequently gets the public attention.

In the climate debate you represent the more moderate voices. Why do their opinions get less publicity?

I think it is related to the dynamics of the media. Dramatizing as well as radically denying presentations are by their polarizing and exciting character more apt to receive attention and rouse interest. Media success is more related to entertainment and less to information and balanced discussions. That is not a complaint, just a statement of fact.

Have climate researchers become more ideological in recent years?

Certainly. There are scientists who ask Mrs. Merkel to undertake certain political actions. Here, some fail to appreciate that public decision-making in Germany is a democratic process and does not rest only on supposed or factual better knowledge.

Related to this, the e-mails and datasets hacked in England mentioned at the beginning may be of interest. Are the allegations made to the climate scientists concerning the published material valid?

There is one thing we can already say: there was no real fabrication. The numbers were not twisted and there was no data massage. The people involved have indeed formed a cartel, and prominently among them are authors of the Copenhagen Diagnosis - for example Michael Mann and Stefan Rahmstorf. A cartel to push the views of its members. And that is highly unscientific, because science must be open and the 'business model' we have here is irreconcilable with that.

How should we interpret the word 'trick' that was mentioned in one of the mails?

That word does not mean there was fabrication. Rather it was considered how the available data were to be used and combined to obtain the right results. These results should have been communicated to the scientific community for critical discussion and verification, but such was apparently not done. And that is the real shortcoming.

So the data should indeed have been made accessible for others.

Understandably, one does not immediately provide new data to other scientists as one wants to valorize them first oneself. After some time however they should come into the open so that others can work on them - even when these others are hostile and just want to find errors. But we all make errors – as well as we make many judgments that could be done differently and that may have big consequences.

I am convinced that the skeptics would only find a few minor errors when the CRU would release the complete data base. But the overall picture that the climate is changing would not be different. That this recompilation has not yet been done is a bit like a Rumpelstiltskin reaction or of a recalcitrant child: one does not want certain people to have the material because in the past these people had been critical of one's own.

Does climate research need more transparency?

For the credibility of our science the possibility to check is an elementary precondition. This possibility however has been hollowed out and this blockade must disappear. I stress again that this does not mean that the results are false. But it is part of the scientific methodology that transparency and reproducibility prevails.

Surprising for outsiders moreover was the sometimes abrasive tone of the published mails.

One should not take that too seriously. I'm certainly not a choir-boy, but I write as I speak. One of the colleagues was less consistent: he is ruder in writing then in conversation. Someone I whom did trust writes about me in a way I would not have expected. When among researchers one has reservations against somebody, one should express these openly to the persons concerned. If found that humanly speaking disappointing. But no one should demand that climate researchers are better than others.

What are the implications of this affair?

The credibility of the societal institution "science" has been damaged: Society organizes, and funds, research as a kind of service and it expects in return that it gets good information und understanding from us about complex phenomena such as swine flu or climate - and not political decisions.

The persons involved should thus restore the required transparency. If moreover the impression has been created that certain scientists have corrupted the peer review process - whether that be so or not - then these scientists should for the time being no longer participate in it or in the IPPC reporting. In politics this would be called 'taking responsibility'. And that is also required here: the researchers concerned should retreat from the committees and no longer review other peoples' work.

Moreover I urgently recommend that CRU publishes voluntarily everything of importance. Otherwise there may be other unpleasant surprises and the hackers might release new material bit by bit. However, a publication would end the discussion.

In the course of this affair the journal "Climate Research", whose chief editor you shortly were before you resigned, has been mentioned several times. What happened?

One paper published in "Climate Research", was not professionally reviewed. In public discussions many questions were raised – which should have been posed during the peer review process: the publication procedure also was inadequate. I wanted to make sure that in the future this would not happen again and I also wanted to make this public. The publisher however was against. Therefore I quit of my own accord.

Time and again, particularly hot discussions flame up about the so called hockeystick curve of Michael Mann, that over a period of 1000 years shows a particularly strong temperature rise for the last century: what is its relevance for climate research today?

The diagram can for example be found in the Copenhagen Diagnosis and is thus still being used. Our critique was not about the statement itself but about the methodology used. Our publication, which at the time helped to initiate the hockeystick debate, is also discussed in the CRU mails. On of the writers of these mails has indeed tried to influence a reviewer of our work - and moreover negatively so. I found that very remarkable. Anyhow, I take off my hat to the young man who withstood the pressure.

The hockeystick has been reproduced using new data and new methods. What should we think of these results?

That is being argued by Michael Mann and co. and is very questionable. With their cartel position they control the publicly perceived discussion and such statements thus arrive uncontested in the public. But the scientific debate about it is still intensive.

According to your own saying, you are more and more being criticized by both sides, by climate skeptics and by climate protectors. Why is that?

I would not call them "climate protectors" - rather 'alarmists'. Both, the skeptics and the alarmists, have one characteristic in common: they are value-driven and only interested in specific statements. The skeptics talk about a 'left conspiracy' and about 'communists', who want a world government to ruin the American economy. And the alarmists argue that climate change is a serious matter and that this is the occasion for making the world a substantially better place and for using resources intelligently. In the extreme case two ideological lines shoot at each other.

Someone like me, who as a scientist would rather argue rationally - when you do this, you get that and otherwise - finds himself between the fronts. I refuse to consider in advance whether my results serve a political cause. I am not a do-gooder. That is however how skeptics and alarmists consider themselves.

Even when you do not consider yourself as a do-gooder: do you have any recommendations for the climate summit?

As an ordinary citizen of Hamburg I would like too see a result that is feasible and does not consist of only hot air, but can be turned into reality. The summit must make sure that emissions are sufficiently reduced so that the climate change does not become too drastic. At the same time we must deploy massive efforts so that the impact of that part of global warming, which has become unavoidable, is intelligently handled - in Hamburg as well as in Shanghai or elsewhere.

Will humanity succeed in reducing climate change to a tolerable level?

We can reduce it, even though I do not believe that we can realize the desired two-degree target. By nature I'm an optimist: when there are challenges new solutions appear. As to technical developments, we will see many things which we cannot yet conceive. All in all, there will be a happy ending, though I do not know when it will happen - certainly not as soon as many would like.

Mr von Storch, thank you for the interview.