Carbon Mitigation Initiative

Stabilization Wedges Introduction

Building the Stabilization Triangle

We already have the technology we need to take the world off the path toward dramatic climate change.

Carbon emissions from fossil fuel burning are projected to double in the next 50 years (Figure 1), keeping the world on course to more than triple the atmosphere's carbon dioxide (CO2) concentration from its pre-industrial level. This path (black line) is predicted to lead to significant global warming by the end of this century, along with decreased crop yields, increased threats to human health, and more frequent extreme weather events.

Figure 1

In contrast, if emissions can be kept flat over the next 50 years (orange line), we can steer a safer course. The flat path, followed by emissions reductions later in the century, is predicted to limit CO2 rise to less than a doubling and skirt the worst predicted consequences of climate change.

Keeping emissions flat for 50 years will require trimming projected carbon output by roughly 8 billion tons per year by 2060, keeping a total of 200 billion tons of carbon from entering the atmosphere (yellow triangle). We refer to this carbon savings as the stabilization triangle.

Figure 2

To keep pace with global energy needs at the same time, the world must find energy technologies that emit little to no carbon, plus develop the capacity for carbon storage. Many strategies available today can be scaled up to reduce emissions by at least 1 billion tons of carbon per year by 2060. We call this reduction a wedge of the triangle (Figure 2). By embarking on several of these wedge strategies now, the world can take a big bite out of the carbon problem instead of passing the whole job on to future generations.

We Have the Technology

Each of the 15 strategies below has the potential to reduce global carbon emissions by at least 1 billion tons per year by 2060, or 1 wedge. A combination of strategies will be needed to build the eight wedges of the stabilization triangle.


efficiency bulb
  1. Double fuel efficiency of 2 billion cars from 30 to 60 mpg.
  2. Decrease the number of car miles traveled by half.
  3. Use best efficiency practices in all residential and commercial buildings.
  4. Produce current coal-based electricity with twice todays efficiency.


  1. Increase wind electricity capacity by 10 times relative to today, for a total of 2 million large windmills.

Fuel Switching

fuel switching
  1. Replace 1400 coal electric plants with natural gas-powered facilities.


solar panel
  1. Install 100 times the current capacity of solar electricity.
  2. Use 40,000 square kilometers of solar panels (or 4 million windmills) to produce hydrogen for fuel cell cars.

Carbon Capture and Storage

carbon capture and storage
  1. Capture AND store emissions from 800 coal electric plants.
  2. Produce hydrogen from coal at six times today's rate AND store the captured CO2.
  3. Capture carbon from 180 coal-to-synfuels plants AND store the CO2.

Biomass Fuels

biomass fuels
  1. Increase ethanol production 12 times by creating biomass plantations with area equal to 1/6th of world cropland.


  1. Add double the current global nuclear capacity to replace coal-based electricity.

Natural Sinks

natural sinks
  1. Eliminate tropical deforestation.
  2. Adopt conservation tillage in all agricultural soils worldwide.

No one strategy will suffice to build the entire stabilization triangle.

New strategies will be needed to address both fuel and electricity needs, and some wedge strategies compete with others to replace emissions from the same source. Still, there is a more than adequate portfolio of tools already available to build the stabilization triangle and control carbon emissions for the next 50 years.

About CMI

The Carbon Mitigation Initiative (CMI) is a 15-year program supported by BP (Ford Motor Company 2000-2009) to find solutions to the greenhouse gas problem. Over 60 CMI researchers in science, engineering, and policy are developing strategies to reduce global carbon emissions safely, effectively, and affordably. CMI is a part of the Princeton Environmental Institute at Princeton University.

Last update: July 27 2011
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CMI is sponsored by BP.