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.