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April 02, 2008
Commentary in Nature
Posted to Author: Pielke Jr., R. | Climate Change | Risk & Uncertainty | Technology Policy
[Update #4: The guys at Grist Magazine apparently have not yet read our paper, which probably explains why one of their commentators explains that everything we say is right but common wisdom, while another says that everything we say is wrong. At least they have their bases covered. Why don't these guys at Grist actually read the paper before commenting? One wonders.]
[Update #3: Andy Revkin of the NYT provides some comments as well here.]
[Update #2: John Tierney of the NYT times provides excerpts of an extended set of comments that I shared with him here.]
[Update: Here is a short interview I did with Scitizen link.]
Tom Wigley, Chris Green, and I have a Commentary in today's Nature on the technology challenge of stabilization. It has already generated some discussion and this discussion will be the focus of some of my posts over the next weeks.
Meantime, please have a look at this summary that Tom, Chris, and I prepared:
PWG on PWG
The challenge of stabilizing the concentration of carbon dioxide (CO2) in the atmosphere may be much more difficult that currently realized. In a commentary published April 3, 2008 in Nature, Roger Pielke, Jr. (University of Colorado), Tom Wigley (National Center for Atmospheric Research) and Chris Green (McGill University) argue that the magnitude of the technology challenge associated with stabilizing the amount of carbon dioxide in the atmosphere may have been significantly underestimated by the Intergovernmental Panel on Climate Change (IPCC).
The reason for this underestimate lies in the assumptions of decarbonization common to all scenarios of future emissions growth used by the IPCC. These assumptions may be far too optimistic, and if so, will hide from view the magnitude of the technology challenge associated with stabilizing the amount of carbon dioxide in the atmosphere. In this commentary the authors reveal these assumptions, and discuss their significance for policy making.
Indeed, the authors present evidence that the first decade of the 21st century has seen greater emissions of CO2 than projected by IPCC due to rapid economic development, particularly in Asia. In recent years, the world as a whole has begun to re-carbonize, breaking a long-term trend in which carbon dioxide per unit energy was assumed instead to continue to decline indefinitely.
Stabilization of the concentrations of CO2 and other greenhouse gases is the primary objective of the United Nations Framework Convention on Climate Change (UNFCCC), approved by almost all counties, including the USA. Stabilization requires, eventually, reducing the emissions of these gases by large amounts relative to today, a task commonly referred to as "mitigation." For CO2, mitigation requires replacing current and likely future fossil-fuel-based energy systems by carbon neutral energy sources -- that is, sources of energy that are either fossil-fuel free, are accompanied by the capture and storage of CO2, or are otherwise carbon-neutral.
The costs of mitigation are generally estimated by comparing emissions under a baseline scenario where emissions evolve in the absence of climate policies, with a scenario in which the emissions are reduced (via climate policy) to achieve a chosen atmospheric concentration, called a stabilization target. Pielke, Wigley and Green note that the standard baseline scenarios considered for these calculations already include large amounts of carbon-neutral technologies that are assumed to be developed and implemented spontaneously. In the cases the authors consider, 57 to 96% of the cumulative emissions reduction required for CO2 stabilization at around 500 ppm have been assumed by IPCC to occur automatically, meaning that the majority of the emissions reduction needed to stabilize concentrations is assumed to occur automatically..
Rather than starting with assumptions about future spontaneous technological innovations, the authors’ calculations begin with a set of "frozen technology" scenarios as baselines, i.e., emissions scenarios in which energy technologies are assumed to remain at present levels. This contrasts with previous approaches, which use baselines that already include major technology changes, and, consequently, large spontaneous increases in carbon-neutral energy sources. With a "frozen technology" approach, the full scope of the carbon-neutral technology challenge is placed into clear view.
With the full scope of the technology challenge placed into view, the question then arises as to how much of this challenge will occur spontaneously, and how much must be driven by new policies. Pielke and his colleagues suggest that the amount of spontaneous development of carbon-neutral energy sources has been overestimated in previous analyses, diverting attention away from technological innovation, thereby underestimating the need for policy-driven technology development.
The authors conclude by saying "… there is no question whether technological innovation is necessary – it is. The question is, to what degree should policy focus explicitly on motivating such innovation? The IPCC plays a risky game in assuming that the spontaneous advancement of technological innovation will carry most of the burden of achieving future emissions reductions, rather than focusing on those conditions necessary and sufficient for such innovations to occur."
Comments
Surprise! Joe Romm doesn't like the commentary:
The Pielke et al. piece is seriously flawed and misleading with conclusions that don't follow from the analysis. As but one example: Five years ago the American Enterprise Institute “proved” that the lowest IPCC emissions projection is too high, and they backed up their conclusion with actual 1990s data, whereas Pielke, Wigley, and Green have “proven” that the highest IPCC emissions projection is too low, and they backed up their conclusion with actual data from this decade. I have debunked the whole thing here: http://climateprogress.org/2008/04/02/nature-pielke-pointless-misleading-embarrassing-ipcc-technology/
02 Apr, 2008 Posted by: Joe Romm
Posted by: Paul Biggs ![[TypeKey Profile Page]](http://sciencepolicy.colorado.edu/prometheus/nav-commenters.gif)
at April 2, 2008 04:07 PM
Hi Roger,
Well, I'm shocked. I don't know how you could manage to get something that actually has science in it published in a major publication on the subject of climate change projections. Congratulations!
If you want to (and are allowed to) follow up your terrific achievement with another paper that has actual science, I have a good topic.
You could write a paper that recommends that the IPCC should drop its "scenario" analysis completely, and switch to probabilistic predictions of *all* climate forcing variables, with resulting probabilistic predictions for temperature rise.
For example, Figure 10.26 of AR4 has approximately the following methane concentrations (in ppb) in the year 2020 for various scenarios:
B1 = 1920
B2 = 1980
A1F1 = 2000
A2 = 2010
A1T = 2010
A1B = 2020
Those (ridiculous) projections could be replaced by realistic probabilistic predictions, e.g.
5% probability methane concentration will be less than 1700 ppb,
50% probability methane concentration will be less than 1800 ppb, and
95% probability methane concentration will be less than 1900 ppb.
The same thing could be done for each climate forcing (warming and cooling) agent, e.g., CO2, black carbon, sulfur dioxide, organic carbon, etc.
I think this would probably be too much real science for Nature. But you the man! Maybe you can get it published. :-)
Mark
Posted by: Mark Bahner at April 2, 2008 07:08 PM
Hi Roger,
Oops. The comment I made above was supposed to be for your Nature Geoscience letter. You can delete the one above.
Sorry about the double post.
Mark
Posted by: Mark Bahner at April 2, 2008 07:20 PM
It appears Joe Romm's beef is that he thinks you (Dr. Pielke) are advocating more R&D at the expense of rapid deployment of existing low/no carbon technologies rather than advocating both. It doesn't sound that way to me. But I think it's an essential question. Which is it?
Posted by: Ricorun at April 3, 2008 02:47 PM
Ricorun-
Thanks for your comments.
I tell my students to watch out for either/or questions in their comprehensive exams. Academics love them, but in the world of policy the answer is invariably "yes" and so it is here as well.
But lets be honest, in the real world new technologies are going to be necessary if stabilization is to be achieved at levels anywhere close to levels currently deemed acceptable. This is just a fact. Some may not like it, but it doesn't make it any less true. See the papers by Hoffert and colleagues that we cite for ample support.
Posted by: Roger Pielke, Jr. at April 3, 2008 03:14 PM
I there is correspondence from Gwyn Prins in Nature:
Radical rethink is needed on climate-change policy
http://www.nature.com/nature/journal/v452/n7187/pdf/452530a.pdf
and he has an article in The Guardian today supporting the Pielke Jr et al commentary:
The road from Kyoto - The strategy has failed. The world must follow Japan in a radical rethink of climate change policy:
http://www.guardian.co.uk/commentisfree/2008/apr/04/climatechange.carbonemissions/print
Posted by: Paul Biggs at April 4, 2008 02:10 AM
Hello Roger,
Joe Romm tries to make a big deal of the alleged contradiction between Steve Hayward’s 2003 AEI paper, which argued that the IPCC’s emission scenarios are too “pessimistic” (Romm’s terminology), and your 2008 paper in Nature (Pielke et al.), which argues that the IPCC scenarios are too “optimistic.” To Romm, this supposed flip-flop shows how duplicitous “deniers/delayers/destroyers” are, making stuff up as we go, whenever this advances our nefarious purposes.
There are two problems with this supposed “gotcha.” First, neither you nor your co-authors (Tom Wigley and Christopher Green) are under any obligation to ensure that your paper squares with something Hayward wrote five years ago. To suggest otherwise, as Romm does, makes sense only on the assumption that Pielke et al. and Hayward are not independent scholars but mere mouthpieces paid by the same master (or masters) to spout a company line. I fear that for Romm, “denial machine” is no mere figure of speech but an actual conspiratorial enterprise.
The main problem, however, with Romm’s claimed “gotcha” is that there is no inherent contradiction between what Hayward said in 2003 and what Pielke et al. are saying today.
Hayward said that the IPCC’s emission scenarios are too pessimistic because, overestimating economic growth, they also overestimate emissions. Pielke et al. say that the scenarios are too optimistic because, overestimating technology change, they underestimate emissions. The two criticisms are not contradictory, because the same model can overestimate both economic growth and technology change. Indeed, since technology change tends to spur growth and vice versa, a model that overestimates growth is also likely to overestimate technology change.
As it happens, Ian Castles and David Henderson (C&H), the economists whose analysis of the IPCC emission scenarios Hayward quoted in the AEI paper, subsequently retracted part of their criticism [Henderson, SRES, IPCC and the Treatment of Economic Issues: What has emerged? Energy & Environment, Vol. 16, Nos. 3&4, 2005].
Although C&H correctly concluded that the IPCC dramatically overstated developing country GDP growth rates, they later learned from Norwegian scholars Bjart Holtsmark and Knut Alfsen (H&A) that the IPCC made a correspondingly large overestimate in the rates of energy-intensity decline in developing countries. Accordingly, C&H no longer maintain that the IPCC scenarios’ exaggerated economic growth rates necessarily lead to inflated emission projections (see p. 559 of Henderson’s paper).
It is thus doubly nonsensical to make an issue out of your seeming disagreement with Hayward. Not only are you not responsible for what Hayward wrote, but three years ago Hayward’s authorities publicly retracted their criticism that the IPCC overestimated emission growth rates.
C&H remain critical of the IPCC’s use of market exchange rates (MER) rather than purchasing power parity (PPP) to calculate developing country GDP. However, they learned from H&A that MER leads not only to an “overestimation of [developing country] economic growth,” but also to “an overestimation of the potential for energy efficiency improvements in the developing countries.” [H&A, PPP-correction of the IPCC emission scenarios: does it matter? Climatic Change, p. 3]
In short, the updated, corrected version of the analysis underpinning Hayward’s article is quite consistent with the main conclusion of Pielke et al., namely, that substantial “energy efficiency improvements and decarbonization” are “already built into the IPCC reference scenarios.”
Posted by: Marlo Lewis at April 4, 2008 01:38 PM
Hello Roger,
Joe Romm tries to make a big deal of the alleged contradiction between Steve Hayward’s 2003 AEI paper, which argued that the IPCC’s emission scenarios are too “pessimistic” (Romm’s terminology), and your 2008 paper in Nature (Pielke et al.), which argues that the IPCC scenarios are too “optimistic.” To Romm, this supposed flip-flop shows how duplicitous “deniers/delayers/destroyers” are, making stuff up as we go, whenever this advances our nefarious purposes.
There are two problems with this supposed “gotcha.” First, neither you nor your co-authors (Tom Wigley and Christopher Green) are under any obligation to ensure that your paper squares with something Hayward wrote five years ago. To suggest otherwise, as Romm does, makes sense only on the assumption that Pielke et al. and Hayward are not independent scholars but mere mouthpieces paid by the same master (or masters) to spout a company line. I fear that for Romm, “denial machine” is no mere figure of speech but an actual conspiratorial enterprise.
The main problem, however, with Romm’s claimed “gotcha” is that there is no inherent contradiction between what Hayward said in 2003 and what Pielke et al. are saying today.
Hayward said that the IPCC’s emission scenarios are too pessimistic because, overestimating economic growth, they also overestimate emissions. Pielke et al. say that the scenarios are too optimistic because, overestimating technology change, they underestimate emissions. The two criticisms are not contradictory, because the same model can overestimate both economic growth and technology change. Indeed, since technology change tends to spur growth and vice versa, a model that overestimates growth is also likely to overestimate technology change.
As it happens, Ian Castles and David Henderson (C&H), the economists whose analysis of the IPCC emission scenarios Hayward quoted in the AEI paper, subsequently retracted part of their criticism [Henderson, SRES, IPCC and the Treatment of Economic Issues: What has emerged? Energy & Environment, Vol. 16, Nos. 3&4, 2005].
Although C&H correctly concluded that the IPCC dramatically overstated developing country GDP growth rates, they later learned from Norwegian scholars Bjart Holtsmark and Knut Alfsen (H&A) that the IPCC made a correspondingly large overestimate in the rates of energy-intensity decline in developing countries. Accordingly, C&H no longer maintain that the IPCC scenarios’ exaggerated economic growth rates necessarily lead to inflated emission projections (see p. 559 of Henderson’s paper).
It is thus doubly nonsensical to make an issue out of your seeming disagreement with Hayward. Not only are you not responsible for what Hayward wrote, but three years ago Hayward’s authorities publicly retracted their criticism that the IPCC overestimated emission growth rates.
C&H remain critical of the IPCC’s use of market exchange rates (MER) rather than purchasing power parity (PPP) to calculate developing country GDP. However, they learned from H&A that MER leads not only to an “overestimation of [developing country] economic growth,” but also to “an overestimation of the potential for energy efficiency improvements in the developing countries.” [H&A, PPP-correction of the IPCC emission scenarios: does it matter? Climatic Change, p. 3]
In short, the updated, corrected version of the analysis underpinning Hayward’s article is quite consistent with the main conclusion of Pielke et al., namely, that substantial “energy efficiency improvements and decarbonization” are “already built into the IPCC reference scenarios.”
Posted by: Marlo Lewis at April 4, 2008 01:40 PM
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