17 May 2011

Socolow: Wedges Were a Mistake

[UPDATE: Socolow responds to Joe Romm, and undercuts many of Romm's arguments (e.g., that a wedge should be thought of over a "few decades", no says Socolow, they were 50 years; that we can reduce emissions by efficiency alone, no says Socolow; that the wedges suggest 450 ppm -- much less 350 ppm -- is a realistic target, Socolow says no. Apparently, Socolow does not read Romm's blog (I've updated the below to acknowledge this).  Romm says he is unfamiliar with my views on climate policy, so I'll send him a link to my book with an invitation to offer a substantive critique.]

National Geographic has a pretty remarkable story up on the so-called "stabilization wedges" approach to reducing emissions (thx DM). The article has a number of lengthy quotes from Robert Socolow (co-author with Stephen Pacala on the paper) in which he says that their paper was misunderstood and misused by the advocacy community.  Socolow's comments reinforce a number of arguments that I make about the wedges in Chapter 2 of The Climate Fix.

Here are a few choice excerpts from the National Geographic article:
When the torrent of predictions about global warming got too depressing, there were Robert Socolow's "wedges."

The Princeton physics and engineering professor, along with his colleague, ecologist Stephen Pacala, countered the gloom and doom of climate change with a theory that offered hope.  If we adopted a series of environmental steps, each taking a chunk out of the anticipated growth in greenhouse gases, we could flatline our emissions, he said. That would at least limit the global temperature rise, he said in a 2004 paper in the journal Science.

The Princeton colleagues even created a game out of it: choose your own strategies, saving a billion tons of emissions each, to compile at least seven "wedges," pie-shaped slices that could be stacked up in a graph to erase the predicted doubling of CO2 by 2050.

It was a mistake, he now says.

"With some help from wedges, the world decided that dealing with global warming wasn't impossible, so it must be easy," Socolow says.  "There was a whole lot of simplification, that this is no big deal."

He said his theory was intended to show the progress that could be made if people took steps such as halving our automobile travel, burying carbon emissions, or installing a million windmills. But instead of providing motivation, the wedges theory let people relax in the face of enormous challenges, he now says.
Socolow takes issue with how his work has been misused by advocates for action:
Socolow said he believes that well-intentioned groups misused the wedges theory. His theory called for efficiency, conservation, and energy alternatives that could keep greenhouse gas emissions at roughly today's levels, offsetting the growth of population and energy demands. Global temperatures would rise by 3°C.

"I said hundreds of times the world should be very pleased with itself if the amount of emissions was the same in 50 years as it is today," he said.

But those inspired by the theory took it farther.  If Socolow's wedges could stabilize emissions with a 3-degree rise, they said, even bigger wedges could actually bring greenhouse gases back down to a level resulting in only a 2-degree rise. (This is the goal that 140 nations have pledged to try to achieve in the Copenhagen Accord.)

"Our paper was outflanked by the left," Socolow said.  But he admits he did not protest enough: "I never aligned myself with the 2-degree statement, but I never said it was too much."

In holding out the prospect of success, adherents stressed the minimal goals, and overestimated what realistically could be achieved.

"The intensity of belief that renewables and conservation would do the job approached religious," Socolow said.
Of course, no one has abused the "wedges" analysis more than Joe Romm who did exactly what Socolow is critical of -- Romm super-sized each one of the wedges, doubled the number needed, and then claimed based on his perversion of the Socolow/Pacala analysis that we have (or soon will have) all the technology needed to stabilize concentrations of carbon dioxide at 450 (or even 350) ppm. It is hard to imagine that Socolow's comments can be in reference to anyone other than Romm, who has probably done more to confuse issues of mitigation policy than anyone [UPDATE: Socolow says he is unfamiliar with Romm's views.].  Back in 2008 I pointed out Romm's egregious misuse of the wedges analysis to imply that achieving deep emissions cuts would be technologically and economically possible with technologies currently (or soon to be) available. The exchange with Romm was precipitated by a paper with Chris Green and Tom Wigley in which we explained how the IPCC had made a similar error in its analysis (here in PDF).

Socolow's strong rebuke of the misuse of his work is a welcome contribution and, perhaps optimistically, marks a positive step forward in the climate debate.


  1. In an argument between Chicken Little and Turkey Lurkey, who is more wrong? And in the argument over how many angels can fit on the head of a pin, does the answer depend on whether the angels are dancing?

    Romm certainly deserves a "wedgie", but the whole conversation would be advanced substantially if the players were more humble by recognizing their ignorance and a lot less hubristic about their understanding of the present state of the climate and their predictions for the future.

  2. Most of the proposed wedges in the original article were highly optimistic at best. Many of them appeared to be completely unfeasible. The idea that they could be expanded to actually reduce emissions should have been ludicrous to any rational observer.

  3. Looks like you shouldn't get so excited; Socolow clarified his statements to Revkin and Romm, undercutting your conceit: http://bit.ly/kslS1t

  4. -3-Erik

    Thanks for the link, but Socolow's comments undercut Romm's arguments pretty comprehensively ... Socolow says he is unfamiliar with Romm's work. Romm says that he is unaware of my views on climate policy. I'll send him a link to my book ;-)

  5. I just sent this invitation to Joe Romm:

    "Hi Joe-

    I see on your blog that you have expressed unfamiliarity with my views on climate policy. I wrote a book called The Climate Fix in which I discuss mitigation, adaptation, geoengineering and other subjects. In it my views on climate policy are expressed.

    If you are interested in actually knowing what my views are, please do have a look. And if you do so, I'd be happy to hear and publish your substantive critique.

    All best,


  6. Roger,

    Socolow's email as reproduced by Joe Romm makes the following relevant points:

    A. Socolow does not agreee with the National Geographic article (from which you extensively quoted) about him, saying "What is not in quotes is just enough “off” in several places to result in my messages being misconstrued."

    In particular, he writes:
    1. “It was a mistake, he now says.” Steve Pacala’s and my wedges paper was not a mistake.
    2. “The wedges paper made people relax.” I do not recognize this thought.
    3. “Well-intentioned groups misused the wedges theory.” I don’t recognize this thought.

    This seems to direcly undercut the main premise of your post, eg your last sentence is in direct contradiction to Socolow's third point. It think it would be good if you updated your post to reflect this.

    B. Socolow: "I did say “The job went from impossible to easy" and "Every wedge was and is a monumental undertaking." That part is in line with your views.

    C is also important, but not directly relevant to the disagreement between you and Joe as I see it.

    In response to your piece he writes: "It is distressing to see so much animus among people who have common goals. The message of Steve’s and my wedges paper was, above all, ecumenical." Of course, this message is equally valid and important to both you and Joe.


  7. -6-Bart

    Thanks. I put a link to Romm's post updating this post right at the top so that people can go read Socolow's elaboration in full, which I certainly encourage them to do. Even after I read those comments I am not as comfortable as you expressing what Socolow actually means, as he takes issue with the NG article, but apparently not his direct quotes, and certainly not the ones highlighted above.

  8. -8-Bart

    Also ... while I appreciate your concern for how Socolow's views are being represented, I do note that you haven't expressed any concern at all about Romm's continuing misrepresentations of my views in that same post.

  9. Your update helpfully point out that Socolow has rebutted Romm's claim that "we can reduce emissions by efficiency alone."

    Can you provide a link to that statement? (In the Socolow response posted on climateprogress, he says, "I did say that there was and still is a widely held belief that the entire job of dealing with climate change over the next 50 years can be accomplished with energy efficiency and renewables." That seems to be the only reference to efficiency in Socolow's comments there, so I presume Socolow has said what you report in another response.)

    Also, I think your link that substantiates Romm's point of view is inadvertently wrong. Romm doesn't make the claim about energy efficiency reducing emissions alone in that blogpost. Can you please help me find where Joe Romm says that?

  10. -9-John

    Thanks, the links are there for a reason ... if you want further info, go to Romm's and search "mckinsey" and you'll find many of his posts on the role of efficiency as a "the core climate solution". On Socolow just read the NG article.