Are the IPCC Scenarios "Unreachable?": An Interview with Dr. Roger Pielke, Jr.
3 Apr, 2008 11:33 am
Scitizen has a 3-question interview with Roger Pielke, Jr., whose letter in this week's Nature with Tom Wigley and Christopher Green explains why they think that the emission scenarios the IPCC produced nearly a decade ago, which are still widely used, are overly optimistic.
Our paper makes the case that the IPCC has built in a large amount of automatic emissions reductions across all of the scenarios that it uses. The IPCC was aware of this, or at least the authors of Chapter 3 of Working Group III, as we reference in our paper. Why this information, and its significance, did not make it into the Summary for Policymakers (SFP) is a question most appropriate for the IPCC.
The IPCC SFP for WG III has the following statement:
"The range of stabilization levels assessed can be achieved by deployment of a portfolio of technologies that are currently available and those that are expected to be commercialised in coming decades."
I have a hard time squaring this conclusion of the IPCC with the analysis presented in our paper, and that in some of our supporting references, especially the work of Hoffert and colleagues.
To be fair to the IPCC, it is not only the scenarios that it relies on that have large built-in reductions in future emissions due to assumptions of decarbonization, but also those of international agencies, governments, oil companies, and most scholars. These assumptions may in the end prove to be correct for the balance of the 21st century, but we should at least be aware of them and their implications. For the first decade of the 21st century, it appears that the assumptions of decarbonization are not accurate, as Figure 2 shows in our paper.
2. What might be the consequences (social, economical) of IPCC policy?
The concern that we express in the paper is that the IPCC presentation of its analysis deemphasizes the important role of technological innovation for energy production and consumption in mitigation. If we deemphasize technological innovation, then we may risk not making those investments necessary for such innovation to actually occur, thereby making the challenge of mitigation that much more difficult.
For example, the head of the IPCC Rajendra Pachauri has often made statements emphasizing the importance of lifestyle changes and deemphasizing technologies. There is a risk that this sends policy makers and the public a misleading message, because technological innovation is necessary and essential to any successful effort at mitigation, quite independent of what lifestyle changes actually occur.
3. Is there an "optimal" ( Ed: most favorable) policy action?
I'm not sure I understand the question, but I'd say "no" there is no optimal policy for climate change, simply because people across society come to the issue with vastly different interests and values on both adaptation and mitigation. So the policies that are implemented will necessarily reflect compromises across these interests, and may not be viewed as optimal by anyone. Of course, this feature doesn't distinguish climate change from most other complex policy issues.
Interview by Audrey Wang
1. Pielke, R. Jr, Wigley, T. & Green, C. Nature 452, 531-532, April 2008. Paper available here.