Climate Stabilization Wedges

by Richard T. Stuebi

The most useful framework for considering solutions to the climate change problem was developed by Professor Robert Socolow of Princeton University.

In a pathbreaking August 2004 Science paper, Socolow (with fellow Princeton co-author Stephen Pacala) coined the concept of “stabilization wedges” to illustrate the types and magnitude of actions that would be required by society to stabilize the climate. Each “wedge” corresponds to one gigaton per year of worldwide carbon reductions by 2050; seven wedges are estimated to be required to cap CO2 concentrations to less than 500 ppm and thereby achieve climate stabilization. (Incidentally, this translates to a global emission reduction of about 1/3 relative to projected business-as-usual levels.)

It is then fairly straightforward mathematics to postulate actions that can achieve one wedge. For instance, an increase in fuel economy from 30 mpg to 60 mpg for 2 billion cars achieves one wedge. The authors then imagine several hypothetical mutually-exclusive wedges, to demonstrate that climate stabilization can be achieved just by using the palette of technologies that are already commercially available (wind, nuclear, solar, efficient lighting, land-use practices, etc.).

At last July’s annual conference of the American Solar Energy Society held in Denver, the plenary discussions were framed around designing relevant climate stabilization wedges for the U.S.: what it would take for the U.S. to achieve its necessary contribution to climate stabilization — a more severe challenge, requiring about a 60-80% emission reduction by mid-century. These plenary discussions, and the resultant calculations, have been aggregated into a new report that presents wedges of emission reduction strategies that the U.S. could undertake.

The results suggest that the U.S. can achieve the required emission reductions through a mix of energy efficiency and renewable energy options alone — without requiring a mass-shift to nuclear. In other words, a robust move to the rich mix of available renewable resources in the U.S. — wind, geothermal, solar and biomass — along with a dedicated focus to capturing the vast efficiency improvement opportunities that can be found in our relatively wasteful energy system can alone produce an aggressive emission reduction to get us to climate stabilization.

Technology advancements can only make it more economic, but the point is: we absolutely can achieve climate stabilization, if we have the will to employ the technologies we already have at hand.

Richard Stuebi is the BP Fellow for Energy and Environmental Advancement at The Cleveland Foundation, and is also Founder and President of NextWave Energy.

1 reply
  1. Bill Barney
    Bill Barney says:

    Thanks for this great posting. I will have to go dig up the Science article and read it. I will also link to your article from Our Task Blog ( so the folks over there can read it. OT Blog is part of an intergenerational dialogue in support of the generation(s) that will have to clean up this mess. Last week Chemical and Engineering News had a great article about the Cherokee Investment Partners' offer to clean up the Bhopal site, and its cool to angry reception from the Indian government and local activists. The article is here for subscribers : fact that a free cleanup offer for one of the world's most notorious sites would result in so much hostility and foot-dragging is an example of why some problems are persistent: the resources and political will are there, but some of the stakeholders have an interest in perpetuating the situation. (I am not specifically criticizing the local activists who object to anyone but Dow paying for the cleanup–but I wonder if they are chasing a lost hope at the expense of the kids who live near and play on the contaminated site today.)Best regards,Bill

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