1. Climate Change Mitigation Strategies— Potentials and Problems Edward S. Rubin Department of Engineering and Public Policy Department of Mechanical Engineering Carnegie Mellon University Pittsburgh, Pennsylvania Presentation to the Workshop on Climate Change, Engineered Systems and Society The National Academies Irvine, California June 7, 2011

2. E.S. Rubin, Carnegie Mellon The Recent National Academies Study: America’s Climate Choices In this talk I will: Focus mainly on the U.S. situation Draw heavily on results of the 2010 ACC panel report on, Limiting the Magnitude of Future Climate Change, supplemented by other materials

3. E.S. Rubin, Carnegie Mellon The Congressional Request The National Academies should … “…investigate and study the serious and sweeping issues relating to global climate change and make recommendations regarding what steps must be taken and what strategies must be adopted in response to global climate change...” (2008) Focus on actions to reduce domestic greenhouse gas emissions and other human drivers of climate change (such as changes in land use), but also consider the international dimensions of climate stabilization

4. Setting goals E.S. Rubin, Carnegie Mellon

5. The Goal of Stabilization 1992 U.N. Framework Convention on Climate Change called for “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system” *192 countries are parties to the convention

6. E.S. Rubin, Carnegie Mellon Dangers of climate change increase with higher global temperature Source: IPCC, 2007

7. E.S. Rubin, Carnegie Mellon Target: limit global mean temperature increase What is a “safe” amount of climate change? What “limits” should be adopted as goals? How do limits on global mean temperature change or other key impacts translate into limits on atmospheric GHG concentrations? Target: limit atmospheric GHG concentrations How do atmospheric GHG concentration limits translate into limits on global GHG emissions? Target: limit global GHG emissions Target Target: limit U.S. GHG emissions What is a reasonable share of U.S. emission reductions relative to the global targets? What is the implied emissions “budget”? Setting GHG Mitigation Goals

8. E.S. Rubin, Carnegie Mellon We suggest that the U.S. establish a “budget” for cumulative GHG emissions over a set period of time We offer a representative range of: 170–200 gigatons (Gt) of CO 2-eq for the period 2012–2050 (corresponds to reductions to ~50% to 80% below 1990 emission levels)* Set an Emissions Budget Business-as-usual emissions would consume these budgets well before 2050; thus, there is a need for URGENCY * Based on results from, Energy Modeling Forum -22 (EMF, 2009) and America’s Energy Future (NAS, 2009)

9. Mitigation options E.S. Rubin, Carnegie Mellon

10. Focus on CO 2 from Energy Use — the Dominant Greenhouse Gas U.S. Greenhouse Gas Emissions weighted by 100-yr Global Warming Potential (GWP) Source: USEPA, 2007 Total in 2005 = 7.26 Gt CO 2 equiv.

11. E.S. Rubin, Carnegie Mellon How Human Activities Generate CO 2 Emissions The blue rectangles are intervention points for mitigation

12. E.S. Rubin, Carnegie Mellon Reduce demand for energy-intensive goods & services Improve the efficiency of energy use (at all stages) Expand use of low- and zero-carbon energy sources Capture and sequester CO 2 directly from ambient air Ways to Reduce CO 2 Emissions All of these options are currently available (to varying degrees)

13. E.S. Rubin, Carnegie Mellon Electricity and Transportation are the Major Sources of U.S. CO 2 Emissions Electricity + Vehicles emit ≈ 75% of all CO 2 Source: Based on USDOE, 2008 U.S. CO 2 Emissions 39.8% Fossil fuels provide 70% of U.S. electricity and emit 40% of CO 2

14. E.S. Rubin, Carnegie Mellon INCREASED ENERGY EFFICIENCY  Building design and systems  Industrial processes  Transportation systems  Electric power systems LOW-CARBON ELECTRICITY  Renewables: wind, hydro, geothermal, solar  Nuclear power  Coal and gas with CCS  Natural gas DECARBONIZED FUELS  Biofuels (based on LCA emissions)  Hydrogen: from renewables, nuclear, natural gas and coal w/CCS  Synthetic fuels from coal, natural gas, biomass, oil sands w/CCS REPLACE FUELS w/ LOW-CARBON ELECTRICITY  Grid-charged batteries for ground transportation  Heat pumps for building furnaces and boilers Technical Options Available

15. E.S. Rubin, Carnegie Mellon Policy Options Available Source: NAS, 2010

16. Mitigation: The Potential (the elegance of analytical solutions) E.S. Rubin, Carnegie Mellon

17. Strategies to Reach GHG Goals Least-cost U.S. energy mix in 2050 for a GHG budget of ~170 Gt CO 2-eq (80% below 1990) Results from energy models show that major changes are needed in the U.S. energy system (similar findings for global analyses) 80% GHG reduction case Source: EMF22, 2009

18. E.S. Rubin, Carnegie Mellon An emissions budget in the range of 170–200 Gt CO 2-eq is technically possible, but could be very difficult to achieve No single solution; different models project different mixes of energy sources and technologies Within the electric power and transportation sectors, essentially all available options would have to be deployed, often at levels close to estimates of what is technically possible Feasible But Not Easy

19. E.S. Rubin, Carnegie Mellon All models project that GDP continues to grow, but at a somewhat lower rate than reference case The magnitude of estimated impact on GDP is especially sensitive to the:  Timing of emission reductions  Availability of advanced technology  Availability and price of international offsets Economic Impact Source: NAS, 2010

20. E.S. Rubin, Carnegie Mellon Projected price of CO 2 emissions under two technology scenarios:  REFERENCE: Continue historical rates of technology improvement  ADVANCED: Strong R&D with more rapid technological change Value of Sustained R&D An early start and a strong R&D program could reduce total costs significantly Source: Kyle et al. 2009

21. E.S. Rubin, Carnegie Mellon 1. Adopt a mechanism for setting an economy-wide carbon pricing system 2. Complement the carbon price with other policies to:  Realize the potential for energy efficiency and low-carbon energy sources for electricity and transport  Accelerate the retirement, retrofitting or replacement of GHG emission-intensive infrastructure  Establish the feasibility of large-scale carbon capture and storage and new nuclear technologies 3. Create new technology choices by investing heavily in research and crafting policies to stimulate innovation Core Policy Recommendations Source: NAS, 2010

22. E.S. Rubin, Carnegie Mellon 4. Consider potential equity implications when designing and implementing climate change-limiting policies, with special attention to disadvantaged populations 5. Establish the United States as a leader to stimulate other countries to adopt GHG reduction targets 6. Enable flexibility and experimentation with policies to reduce GHGs at the regional, state and local levels 7. Design policies that balance durability and consistency with flexibility and capacity for modification as we learn from experience Core Recommendations (con’t.) Source: NAS, 2010

23. Mitigation: The Problems (the messiness of real-world solutions) E.S. Rubin, Carnegie Mellon

24. Still No Political Consensus on Key Issues Importance and urgency of addressing climate change Role of developed vs. developing nations Cost of mitigation Best or preferred policy measure(s) Distribution of costs across society and regions Availability of some mitigation options (at scale) Acceptability of some mitigation options

25. E.S. Rubin, Carnegie Mellon Still No Global or National Mitigation Program COP 15 (Copenhagen) failed to produce an international accord on GHG reductions The 111 th U.S. Congress failed to enact a climate bill (after adoption by the House)

26. E.S. Rubin, Carnegie Mellon Even Here in California … Source: HuffPost, 2011 Source: KDKA Climate Watch, 2011

27. E.S. Rubin, Carnegie Mellon But Many Regional, State, Local and Private Initiatives Underway Source: Pew Climate Center, 2011

28. E.S. Rubin, Carnegie Mellon New Educational Initiatives Would be Extremely Valuable Source: L. Fleishman, 2011 At Carnegie Mellon we also have a long history of educational activities related to climate change, technology and society. Here are a just a few examples.

29. E.S. Rubin, Carnegie Mellon What Will the Future Bring ? Education can make a difference The climate problem is not going away !

30. E.S. Rubin, Carnegie Mellon Thank You rubin@cmu.edu