The ''Climate Stabilization Wedges'' are an approach produced by
Princeton University
Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the n ...
researchers,
Stephen Pacala and
Robert H. Socolow
Robert Harry Socolow (born December 27, 1937) is an American theoretical physicist and professor emeritus of Mechanical and Aerospace Engineering at Princeton University.
Education
Robert Socolow has stated his parents and teachers imbued him wi ...
, looking at
climate change mitigation scenarios
Climate change scenarios or socioeconomic scenarios are projections of future greenhouse gas (GHG) emissions used by analysts to assess future vulnerability to climate change. Scenarios and pathways are created by scientists to survey any long ...
. The project was funded by
Ford Motor Company
Ford Motor Company (commonly known as Ford) is an American multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. The company sells automobiles ...
between 2000 and 2009 and has been receiving funding from
BP since 2000. The goal of the approach is to demonstrate that global warming is a problem which can be attacked using today's commercially available technologies to reduce . The objective is to stabilize concentrations under 500
ppm for the next fifty years, using wedges from a variety of different strategies which fit into the stabilization triangle. A newer estimate by the original authors indicated that by 2011, the number of necessary wedges had increased from seven to nine. This was due to the continuing increase in emissions since the original 2004 paper which determined the number of wedges that would have been necessary, if serious action to mitigate climate change had begun then.
Concept
Scenario
Emissions of
and other
greenhouse gases
A greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor (), carbon dioxide (), meth ...
have been increasing ever since the
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. If the trend continues to hold, emissions will double by 2055. To prevent the worst consequences of
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes ...
, scientists recommend freezing and reducing net global emissions immediately.
Stabilization triangle
If global emissions of are graphed for the next 50 years, the difference between the business as usual scenario and the flat path forms a triangle. This triangle is known as the
stabilization triangle
Stabilizer, stabiliser, stabilisation or stabilization may refer to:
Chemistry and food processing
* Stabilizer (chemistry), a substance added to prevent unwanted change in state of another substance
** Polymer stabilizers are stabilizers use ...
. Pacala and Socolow divided this hypothetical triangle into seven stabilization wedges, which represent different measures that must be taken to reduce emissions. When speaking of different strategies to reduce emissions, the language "to reduce one wedge's worth," is often employed, and by reducing the stabilization wedge of fourteen gigatons of into seven wedges, the task is much easier to conceptualize.
Wedge strategies
As Pacala and Socolow originally presented the wedges concept in ''
Science
Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earli ...
'', there are fifteen different wedge strategies.
Regarding the specific number, Socolow says that he and Pacala didn't include all of the possibilities, but that "It was a matter of rhetoric to stop at 15. And exhaustion. There was nothing magic about 15."
On the CMI website, the same strategies are presented and expanded upon in detail, and are re-organized into nine categories (as of 2020):
#Efficiency
#Fuel switching
#Carbon capture and storage
#Forest and agricultural soils
#Nuclear
#Wind
#Solar
#Biomass fuels
#Natural sinks
Uses
Because of the simplicity of the wedge game, it has become popular as a communication tool for
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes ...
mitigation. It is used in a variety of arenas and by a variety of players including businessmen, politicians, teachers, and students. David Hawkins, climate director at the
Natural Resources Defense Council
The Natural Resources Defense Council (NRDC) is a United States-based 501(c)(3) non-profit international environmental advocacy group, with its headquarters in New York City and offices in Washington D.C., San Francisco, Los Angeles, Chicago, ...
, puts the ease of use of the Wedge Game this way:
Education
The Carbon Mitigation Initiative (CMI) permits anyone to use the game and make use of their materials, provided that they share the results with CMI. Because it is so widely accessible, it has become included in certain high school curricula. The Keystone Center has deemed the ''Stabilization Wedge Game'' to fulfill the following
National Education Standards: S1, S6, LA4, LA5, C4, C5, E1, G1, G5, and WH9.
The
American Association for the Advancement of Science
The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsi ...
hosted a conference for educators at the
Hilton in
San Francisco
San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the List of Ca ...
2007-02-18. Collaborating with AAAS were the
National Science Teachers Association
The National Science Teaching Association (NSTA), founded in 1944 (as the National Science Teachers Association) and headquartered in Arlington, Virginia, is an association of science teachers in the United States and is the largest organization ...
and the
United Educators of San Francisco (representing the
National Education Association
The National Education Association (NEA) is the largest labor union in the United States. It represents public school teachers and other support personnel, faculty and staffers at colleges and universities, retired educators, and college stud ...
and the
American Federation of Teachers
The American Federation of Teachers (AFT) is the second largest teacher's labor union in America (the largest being the National Education Association). The union was founded in Chicago. John Dewey and Margaret Haley were founders.
About 60 p ...
). Socolow and Hotinski personally presented the Stabilization Wedge concept at the event.
Business
The ''Stabilization Wedge Game'' is also used as a centerpiece for business seminars. Business executives played the game at as seminar held by the
Sustainable Enterprise Academy at
York University
York University (french: Université York), also known as YorkU or simply YU, is a public research university in Toronto, Ontario, Canada. It is Canada's fourth-largest university, and it has approximately 55,700 students, 7,000 faculty and staf ...
in
Toronto
Toronto ( ; or ) is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the List of the largest municipalities in Canada by population, most pop ...
.
Criticism
The primary critique of the Wedge Game is that it is too simple, especially regarding the economic aspect of
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes ...
mitigation. The materials provided by CMI only attach one, two, or three dollar signs to each wedge as a broad estimate of the expense of each option.
James L. Connaughton, former chairman of the White House Council on Environmental Quality in the Bush Administration, is a critic of the Wedge Game for its oversimplicity, and he has even said that some of the numbers used by Socolow and Pacala, such as 550 ppm as a maximum allowable target for , lack a scientific basis.
Richard G. Richels
Richard "Rich" Gayle Richels directs global climate change research at the Electric Power Research Institute. Richels received a BS degree in physics from the College of William & Mary. He was awarded MS and PhD degrees in decision science from Ha ...
, a senior engineer at the
Electric Power Research Institute
EPRI, is an American independent, nonprofit organization that conducts research and development related to the generation, delivery, and use of electricity to help address challenges in the energy industry, including reliability, efficiency, affo ...
, says that the lack of economic precision in the game could create misconceptions:
Another criticism of the game is that one of the premises, i.e. that humanity already has the tools and technologies to halt climate change, is misleading. Marty Hoffert of the
New York University
New York University (NYU) is a private research university in New York City. Chartered in 1831 by the New York State Legislature, NYU was founded by a group of New Yorkers led by then- Secretary of the Treasury Albert Gallatin.
In 1832, ...
Physics Department claims that while the technologies are available in a technical sense, they are not available in an operational sense, and it will take a massive mobilization to make progress. Hoffert explains:
In a 2010 Science article, Hoffert also suggested that 18-25 wedges may be necessary to achieve the goal, given the higher rates of emission growth that have occurred since the original study, even if no new sources were added beginning in 2010.
In June 2008,
Joseph Romm argued in ''Nature'' magazine that "If we are to have confidence in our ability to stabilize carbon dioxide levels below 450 p.p.m. emissions must average less than 5 GtC per year over the century. This means accelerating the deployment of the... wedges so they begin to take effect in 2015 and are completely operational in much less time than originally modelled by Socolow and Pacala."
A final criticism is that the Wedge Game focuses on
technological fix
A technological fix, technical fix, technological shortcut or (techno-)solutionism refers to attempts to use engineering or technology to solve a problem (often created by earlier technological interventions).
Some references define technolo ...
es rather than fundamentally challenging the endless growth economy that is at the heart of global climate change. The 2007 IPCC reports state clearly that economic and demographic growth are the fundamental drivers of global climate change. Yet of the fifteen wedges developed by Pacala and Socolow, only one—halving the number of miles driven by the world's automobile fleet—might be considered a "demand reduction" wedge. None of their wedges treat population reduction.
References
{{Reflist
Environmental education video games