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Debate: Did Copenhagen Organizers Exaggerate the Science?

Last week's Copenhagen Climate Congress billed itself as an update on the 2007 Intergovernmental Panel on Climate Change report, because much of the data reviewed in that authoritative study is already more than 5 years old. But some scientists at the meeting felt that organizers of the conference may have exaggerated the extent to which the situation has worsened since that report and may have given the false impression that six "messages" released at the end of the 3-day meeting represented a consensus of the roughly 2000 scientists who were there. ("There is no excuse for inaction" was among them.) Below, with permission, we reprint an e-mail to ScienceInsider from Chris Field, one of three co-chairs of the next IPCC report, and a response from Congress organizer Katherine Richardson of the University of Copenhagen.

Copenhagen attendees, feel free to post in the comments.

From Chris Field, an ecologist at the Carnegie Institution for Science:

As you probably know, I think it is important for the scientific community to stick  to the evidence. All of the science I saw at the Copenhagen meeting was excellent, but I was not entirely comfortable with the communications strategy. The overwhelming message from the Congress, at least the message picked up in the press, is that the situation with climate change is now known to be much more serious than the full range discussed in the IPCC. I think the evidence is leaning in this direction, but it is not yet conclusive.

It is clear that, from 2000 to 2007, the forcing of climate by GHG emissions was at or above the full range of IPCC scenarios, but we don't yet know much about the likely responses to this. The material on Amazon forest dieback was in the IPCC assessment as were the numbers on recent sea level (thought the IPCC did not use the information on recent contributions from land ice in their estimate for 21st century warming.)

Even more problematic, the Congress organizers were very unclear on the difference between their statement at the end of the meeting and the incredibly thorough, careful IPCC review and evaluation process. Whether or not the organizers intended it, some of the coverage gave the impression that the final statement was approved by all of the scientists. I am not aware of any vetting of the statement among the broad community of scientists who participated in the meeting. I thought the closing session was very interesting, but I also thought that the scientists who spoke were clearer than the broader scientific community on things like the consensus on a 2 degree target.

The question about how scientists can communicate risk is the critical one in all of this.  Where is the right balance between a dispassionate discussion of probability density functions and scaring the pants of people? Personally, I think the way forward has three components. First, the scientists need to get better at communicating the subtleties, as well as the big picture. Second, the stakeholders need to be educated enough to make good decisions based on complicated information. Third, the scientists need to be supported with partnerships from organizations like Climate Central, UCS, and EDF, organizations that are focused on finding the best way to communicate complicated scientific material.

I don't have a mature opinion on whether the doom and gloom is effective. In the long run, I would like the public to see information from the scientific community as clear and balanced. The challenge is that, when an audience is not very sophisticated scientifically, it can be very difficult to find a way to be both clear and balanced.

Katherine Richardson, an organizer of the conference, responds in an e-mail to ScienceInsider:

I am essentially in agreement with Chris. I do not believe that "gloom and doom" is the way forward either! It is interesting that the focus in the media (and something that clearly got across to Chris) was that we were saying that the message now from natural science is much more serious than it was in the 2007 IPCC report. It is true that scientists at the Congress indicated that sea-level rise will probably be more dramatic than was indicated in the IPCC report but this cannot really surprise anyone as the IPCC, itself, reported that they did not have the necessary data to take all processes influencing sea-level rise into account!

Otherwise, on the natural science side, we tried very hard to send the message that we now have 4-5 years more data than the IPCC had (due to the time constraints in their process). Essentially, the IPCC made predictions about the future. Given that we now have several years more data, we can essentially "test" the IPCC predictions and we arrive at the conclusion (i.e., message 1) that the climate system is tracking the "worst case scenario" (or worse in the case of ice melt and sea-level rise) presented by the IPCC. Thus, on the natural science side of things, we really did nothing more than, once again, bring the IPCC conclusions into the public arena. It's worth mentioning that most of the messages presented to the Danish Prime Minister in the Closing Session were not "gloom and doom" but instead that "we really do have a lot of tools in our toolbox that can be used to reduce the risk presented by man-made climate change".


The messages delivered to [Prime Minister Anders Rasmussen] in the Closing Session represent a draft of the major messages to be contained in the Congress synthesis being produced in the coming months. These messages were drafted based on input from the session chairs and a reading of the 1600 + abstracts submitted to the meeting...

Ultimately, the Congress will produce two products: 1) a book aiming at an academic audience to be published by Cambridge University Press and 2) a synthesis report that has the purpose of explaining the current state of understanding concerning man-made climate change (and what we can do about it!) to the non-scientist, i.e. politicians, media and interested citizens. ...When it is finished, it will be reviewed by the Earth System Science Partnership (ESSP), the session chairs, and a group of experts identified by the IARU universities.


It occurs to me that Chris is possibly mixing the verbal debate and the written messages that were given to the PM. The content of the actual debate was, of course, only the opinion of the actual scientists involved. It is the written statements he received (and which are on the web site) that I refer to in my mail to Science. I thought, however, that the discussion was good in that it exemplified the communication challenges we as scientists have. When a scientist said that he could not say with certainty that a 2 degree temperature rise was "safe", the PM turned around and accused the scientist as saying a 2 degree rise was "unsafe". We were obviously flirting with the risk discussion there but it was not the time or place to pursue it!