1. Stabilization Wedges: Mitigation Tools for the Next Half-Century Robert Socolow Princeton University socolow@princeton.edu World Bank Washington, DC March 6, 2006 This talk is based on a paper by Stephen Pacala and Robert Socolow, published in the August 13, 2004, issue of Science, 305 (5686), pp. 968-972, and its Supporting Online Material, available at www.princeton.edu/~cmi socolow@princeton.eduwww.princeton.edu/~cmi

2. What if the fossil fuel future is robust, but the Greenhouse problem is severe? Will the fossil fuel system wither away? YESNO Will the case for Greenhouse damage wither away? YESA nuclear or renewables world unmotivated by climate. Most people in the fuel industries and most of the public have been here. NOEnvironmentalists, nuclear advocates are often here. OUR WORKING ASSUMPTIONS

3. Outline of Talk 1.The Wedges Model: A simple quantification of carbon mitigation as the need for seven wedges 2.Some specific wedges 3.The challenge of meeting Basic Human Needs is at most 0.2 wedges. 4. Parting thoughts.

4. 20552005 14 7 1955 0 1.9  2105 Past Emissions Historical emissions Billion of Tons of Carbon Emitted per Year

5. 20552005 14 7 1955 0 1.9  2105 The Stabilization Triangle O Interim Goal Billion of Tons of Carbon Emitted per Year Currently projected path = “ramp” Historical emissions Flat path Stabilization Triangle

6. 20552005 14 7 Billion of Tons of Carbon Emitted per Year 1955 0 Stabilization Triangle Currently projected path = “ramp” Flat path Historical emissions 1.9  2105 Easier CO 2 target ~850 ppm Tougher CO 2 target ~500 ppm Beat doubling or accept tripling O Interim Goal

7. The Interim Goal is Within Reach Reasons for optimism that global emissions in 2055 need not exceed today’s emissions: The world today has a terribly inefficient energy system. Carbon emissions have just begun to be priced. Most of the 2055 physical plant is not yet built

8. 20552005 14 7 Billion of Tons of Carbon Emitted per Year 1955 0 Currently projected path Flat path Historical emissions 1.9  2105 14 GtC/y 7 GtC/y Seven “wedges” Wedges O

9. What is a “Wedge”? A “wedge” is a strategy to reduce carbon emissions that grows in 50 years from zero to 1.0 GtC/yr. The strategy has already been commercialized at scale somewhere. 1 GtC/yr 50 years Total = 25 Gigatons carbon Cumulatively, a wedge redirects the flow of 25 GtC in its first 50 years. This is 2.5 trillion dollars at $100/tC. A “solution” to the CO 2 problem should provide at least one wedge.

10. Energy Efficiency Decarbonized Electricity Fuel Displacement by Low-Carbon Electricity Forests & Soils Decarbonized Fuels Stabilization Triangle 20042054 7 GtC/y 14 GtC/y Fill the Stabilization Triangle with Seven Wedges Methane Management

11. Humanity Already Has The Tools READINESS: All wedge technologies are already deployed somewhere at commercial scale. PORTFOLIO: No single wedge technology can do the whole job, or even half the job. CHOICE: Not every wedge technology is needed.

12. Outline of Talk 1.The Wedges Model: A simple quantification of carbon mitigation as the need for seven wedges 2.Some specific wedges 3.The challenge of meeting Basic Human Needs is at most 0.2 wedges. 4. Parting thoughts.

13. Electricity Transportation Heating Allocation of 6.2 GtC/yr includes coal for heating and cooking

14. Efficient Use of Fuel transport lifestyle Effort needed by 2055 for 1 wedge: 2 billion cars at 60 mpg instead of 30 mpg.

15. Efficient Use of Electricity buildings industrypower Effort needed by 2055 for 1 wedge:. 25% - 50% reduction in expected 2055 electricity use in commercial and residential buildings

16. Wind Electricity Effort needed by 2055 for 1 wedge: One million 2-MW windmills displacing coal power. Today: 50,000 MW (1/40) Prototype of 80 m tall Nordex 2,5 MW wind turbine located in Grevenbroich, Germany (Danish Wind Industry Association)

17. Electricity Effort needed by 2055 for 1 wedge: 700 GW (twice current capacity) displacing coal power. Nuclear Graphic courtesy of NRC Phase out of nuclear power creates the need for another half wedge.

18. Power with Carbon Capture and Storage Graphics courtesy of DOE Office of Fossil Energy Effort needed by 2055 for 1 wedge: Carbon capture and storage at 800 GW coal power plants.

19. Graphics courtesy of DOE Office of Fossil Energy Steam plant by river Gasifier Oxygen plant Coal feeder ramp Gas turbine powered by CO + H 2 IGCC plants are nearly coal CCS plants BP will use petcoke and add at Carson refinery, California, USA: 1)CO 2 capture [CO + H 2 O  CO 2 + H 2, CO 2 - H 2 separation, CO 2 absorption ]; 2)H 2 to turbine for power; 3) CO 2 pressurization and export off site for EOR.

20. Carbon Storage Effort needed by 2055 for 1 wedge: 3500 Sleipners @1 MtCO 2 /yr 100 x U.S. CO 2 injection rate for EOR A flow of CO 2 into the Earth equal to the flow of oil out of the Earth today Graphic courtesy of Statoil ASA Graphic courtesy of David Hawkins Sleipner project, offshore Norway

21. Already, in the middle of the Sahara! At In Salah, Algeria, natural gas purification by CO 2 removal plus CO 2 pressurization for nearby injection Separation at amine contactor towers

22. The Future Fossil Fuel Power Plant Shown here: After 10 years of operation of a 1000 MW coal plant, 60 Mt (90 Mm 3 ) of CO 2 have been injected, filling a horizontal area of 40 km 2 in each of two formations. Assumptions: 10% porosity 1/3 of pore space accessed 60 m total vertical height for the two formations. Note: Plant is still young.

23. Biofuels Effort needed by 2055 for 1 wedge: Two billion 60 mpg cars running on biofuels 250 million hectares of high-yield crops (one sixth of world cropland) Usina Santa Elisa mill in Sertaozinho, Brazil (http://www.nrel.gov/data/pix/searchpix.cgi?getrec=5691971&display_type=verbose&search_reverse=1_

24. Coal-based Synfuels with CCS* *Carbon capture and storage Coal-based Synfuels with CCS* *Carbon capture and storage Effort needed for 1 wedge by 2055 Capture and storage of the CO 2 byproduct at plants producing 25 million barrels per day of coal-based synfuels Assumption: half of C originally in the coal is captured, half goes into synfuels. Graphics courtesy of DOE Office of Fossil Energy Result: Coal-based synfuels have no worse CO 2 emissions than petroleum fuels, instead of doubled emissions.

25. Total: 14 GtC/y Possible 14 GtC/y and 7 GtC/y worlds in 2055 Total: 7 GtC/y You can play too!

26. Summary: What’s appealing about stabilization wedges? The stabilization triangle: Does not concede doubling is inevitable. Shortens the time frame to within business horizons. The wedge: Decomposes a heroic challenge (the Stabilization Triangle) into a limited set of monumental tasks. Establishes a unit of action that permits quantitative discussion of cost, pace, risk. Establishes a unit of action that facilitates quantitative comparisons and trade-offs.

27. Outline of Talk 1.The Wedges Model: A simple quantification of carbon mitigation as the need for seven wedges 2.Some specific wedges 3.The challenge of meeting Basic Human Needs is at most 0.2 wedges. 4. Parting thoughts.

28. Basic Human Needs and Fossil Energy The challenge of meeting Basic Human Needs for electricity and clean cooking fuels is widely understood to be political, not technical: Power can be brought to all villages. The indoor air quality catastrophe related to cooking fuels in rural and urban areas can be solved with modern fuels. The diesel fuel for village-scale engines and the LPG (propane) or DME (dimethyl ether) fuel for clean cooking can be produced from biomass, natural gas, crude oil, or coal. The following four slides explain that meeting these needs for all humanity has a negligible effect on global carbon emissions.

29. Basic Human Needs and Carbon Basic Human Need People without access (billions) Sufficiency (per capita-year) Carbon required (GtC/yr) Electricity1.650W0.15* Clean cooking fuel 2.635 kg propane0.07 Total0.22 † * using global average C-intensity of power in 2002: 160 kgC/kWh Instantly meeting Basic Human Needs for electricity and clean cooking fuel would produce only a three percent increase in global CO 2 emissions. Including coal and kerosene not burned, estimates would be still less. † current global carbon emissions: 7 GtC/yr

30. -0.15 wedges: Faster provision of electricity for 1.6 billion people Business As Usual Accelerated Access 2005 ‘ ‘ ‘ 2030 2055 0.15 GtC/yr 3.75 GtC 1.6 Billion people get access to 600 kWh/yr of electricity by 2030 in AA, but only by 2055 in BAU. Electricity is provided at the current world average carbon intensity: 160 gC/kWh. With linear ramps, AA adds 3.75 GtC of CO 2 emissions to the atmosphere. One “stabilization wedge” is 25 GtC of avoided emissions, so following AA instead of BAU is -0.15 wedges.

31. -0.07 wedges: Faster provision of clean cooking fuels for 2.6 billion people Business As Usual Accelerated Access 2005 ‘ ‘ ‘ 2030 2055 0.07 GtC/yr 1.75 GtC 2.6 Billion people get access to 35 kg/yr of LPG (propane) or equivalent clean cooking fuel by 2030 in AA, but only by 2055 in BAU. With linear ramps, AA adds 1.75 GtC of CO 2 emissions to the atmosphere. One “stabilization wedge” is 25 GtC of avoided emissions, so following AA instead of BAU is -0.07 wedges.

32. 20552005 14 7 Billion of Tons of Carbon Emitted per Year 1955 0 projected path Flat path Historical emissions 1.9  2105 14 GtC/y 7 GtC/y Seven “wedges” Wedges O Basic Human Needs for cooking and electricity

33. Problems of Poverty, Problems of Modernity Distinguish problems of poverty from problems of modernity. 1.Problems of poverty are largely a matter of political will. They are solved when governments are sufficiently motivated to give priority to equity and public health. 2.Problems of modernity require more than political will. Examples are the growing scarcity of low-cost hydrocarbons and the build-up of CO 2. No country can solve such problems on its own. Still, there is an immense amount that every country can do. Both kinds of problems are daunting and urgent. But they almost do not overlap.

34. Outline of Talk 1.The Wedges Model: A simple quantification of carbon mitigation as the need for seven wedges 2.Some specific wedges 3.The challenge of meeting Basic Human Needs is at most 0.2 wedges. 4. Parting thoughts.

35. Emission Commitments from Capital Investments Historic emissions, all uses 2003-2030 power-plant lifetime CO 2 commitments WEO-2004 Reference Scenario. Lifetime in years: coal 60, gas 40, oil 20. Policy priority: Deter investments in new long-lived high-carbon stock: not only new power plants, but also new buildings. Needed: “Commitment accounting.” Credit for comparison: David Hawkins, NRDC

36. New Coal Build by Decade Source: IEA,WEO 2004; Reference Scenario 221 500 670 Total: 1391 GW

37. Mitigate in developing countries now! Some argue that developing countries should not be burdened with carbon mitigation until significant steps have been taken in industrialized countries. This formulation is seriously misguided. Much of the world’s construction of long-lived capital stock is in developing countries. Unless energy efficiency and carbon efficiency are incorporated into new buildings and power plants now, wherever they are built, these facilities will become a liability when a price is later put on CO 2 emissions. Instead, call for “leapfrogging”: The introduction of advanced technology in developing countries first, or at least no later than in industrialized countries. The world learns faster, reducing everyone’s costs. Leapfrogging is a path to globally coordinated mitigation. How to compensate those who move first is a separable challenge.

38. Consensus Building via Wedges? Advocates of particular wedges agree: 1.It is already time to act. 2.It is too soon to pick “winners.” 3.Subsidy of early stages is often desirable. 4.At later stages, markets help to choose the best wedges. 5.The best wedges for one country may not be the best for another. 6.The environmental and social costs of scale-up need attention. Can a consensus for early action be built on stabilization wedges?

39. National subsidies have elicited wedge technologies at large scale Wedges TechnologySubsidy CO 2 transportEOR (U.S.) CO 2 geological storageEOR (U.S.), Sleipner (Norway) WindWind electricity (Germany, Denmark, U.K.) Nuclear powerNuclear power (U.S., Russia, France) Coal-to-H 2 Fertilizer (China) BiofuelsSugarcane ethanol (Brazil), wood waste (Sweden) Coal-to-liquids (negative wedges)Synfuels (South Africa) All of the wedge technologies have already been commercialized at scale, but generally in only a few countries. Most subsidies have been motivated by energy security, not climate. The whole world has learned from these national experiences.

40. $100/tC Form of EnergyEquivalent to $100/tC Natural gas$1.50/1000 scf Crude oil$12/barrel Coal$65/U.S. ton Gasoline25¢/gallon (ethanol subsidy: 50¢/gallon) Electricity from coal2.2¢/kWh (wind and nuclear subsidies: 1.8 ¢/kWh) Electricity from natural gas1.0¢/kWh Today’s global energy system$700 billion/year (2% of GWP) Carbon emission charges in the neighborhood of $100/tC can enable scale-up of most of the wedges. (PV is an exception.) $100/tC is approximately the EU trading price for the past six months.

41. A world transformed by deliberate attention to carbon A world with the same total CO 2 emissions in 2055 as in 2005 will also have: 1.Institutions for carbon management that reliably communicate the price of carbon. 2.If wedges of nuclear power are achieved, strong international enforcement mechanisms to control nuclear proliferation. 3.If wedges of CO2 capture and storage are achieved, widespread permitting of geological storage. 4.If wedges of renewable energy and enhanced storage in forests and soils are achieved, extensive land reclamation and rural development. 5.A planetary consciousness. Not an unhappy prospect!

42. Can We Do It? People are becoming increasingly anxious about our limited understanding of the experiments we are performing on the only Earth we have… …and are learning that there are ways to live more cautiously. We should anticipate a discontinuity: What has seemed too hard becomes what simply must be done. Precedents include abolishing child labor, addressing the needs of the disabled, and mitigating air pollution.

43. Two Messages for the World Bank audience 1.Meeting Basic Human Needs has a negligible impact on the climate problem 2.Mitigation must begin now in developing countries.