Executive Summary

8.1 Introduction

8.1.1 Summary of Mitigation Cost Analysis in the Second Assessment Report
8.1.2 Progress since the Second Assessment Report
8.1.3 Coverage

8.2 Impacts of Domestic Policies

8.2.1 Gross Aggregated Expenditures in Greenhouse Gas Abatements in Technology-rich Models

8.2.1.1 National and Regional Cost Studies Assuming Large Potentials for Efficiency Gains (the Impact of No Regrets or Non-price Policies)
8.2.1.2 Bottom-up Costs Resulting from Carbon Pricing (Developed Countries)

8.2.1.2.1 Cost Discrepancies that Result from Specific Country Conditions
8.2.1.2.2 Discrepancies in Results Due to Modelling and Scenario Assumptions

8.2.1.3 Country Studies for Developing Countries
8.2.1.4 Common Messages from Bottom-up Results

8.2.2 Domestic Policy Instruments and Net Mitigation Costs

8.2.2.1 Aggregate Assessment of Revenue-raising Instruments

8.2.2.1.1 Net Economic Costs under Lump-sum Recycling
8.2.2.1.2 Carbon Taxes and Reducing Payroll Taxes
8.2.2.1.3 Other Forms of Taxes Reduction
8.2.2.1.4 Conclusions: Interest and Limits of Aggregate Analysis

8.2.2.2 Mitigating Sectoral Implications:

8.2.2.2.1 Tax Exemption
8.2.2.2.2 Tax Differentiation
8.2.2.2.3 Compensating or Subsidizing Mitigation Measures
8.2.2.2.4 Free Allocation of Emissions Permits
8.2.2.2.5 Conclusions

8.2.2.3 The Distributional Effects of Mitigation

8.2.3 The Impact of Considering Multiple Gases and Carbon Sinks
8.2.4 Ancillary Benefits

8.2.4.1 The Evaluation of the Ancillary Public Health Impacts
8.2.4.2 Summarizing the Ancillary Benefit Estimates

8.2.4.2.1 Presentation of the Studies
8.2.4.2.2 Evaluation of the Studies

8.2.4.3 Why Do Studies for the Same Country Differ?
8.2.4.4 Conclusions

8.3 Interface between Domestic Policies and International Regimes

8.3.1 International Emissions Quota Trading Regimes

8.3.1.1 “Where Flexibility”
8.3.1.2 Impacts of Caps on the Use of Trading
8.3.1.3 The Double Bubble

8.3.2 Spillover Effects: Economic Effects of Measures in Countries on Other Countries

8.3.2.1 Impact of Emissions Trading
8.3.2.2 Effects of Emission Leakage on Global Emissions Pathways
8.3.2.3 Effects of Possible Organization of Petroleum Exporting Countries Response
8.3.2.4 Technological Transfers and Positive Spillovers

8.4 Social, Environmental, and Economic Impacts of Alternative Pathways for Meeting a Range of Concentration Stabilization Pathways

8.4.1 Alternative Pathways for Stabilization Concentrations
8.4.2 Studies of the Costs of Alternative Pathways for Stabilizing Concentrations at a Given Level
8.4.3 Economywide Impact of CO₂ Stabilization in the Post-SRES Scenarios
8.4.4 Reasons Why Energy-economy Models Tend to Favour Gradual Departure from Baseline in the Near-term
8.4.5 Critical Factors Affecting the Timing of Emissions Reductions: The Role of Technological Change

8.4.5.1 ITC through Dedicated R&D
8.4.5.2 Learning by Doing (LBD)
8.4.5.3 The Distinction Between Action and Abatement

References

Co-ordinating Lead Authors:
JEAN-CHARLES HOURCADE (FRANCE), PRIYADARSHI SHUKLA (INDIA)

Lead Authors:
Luis Cifuentes (Chile), Devra Davis (USA), Jae Edmonds (USA), Brian Fisher (Australia), Emeric Fortin (France), Alexander Golub (Russian Federation), Olav Hohmeyer (Germany), Alan Krupnick (USA), Snorre Kverndokk (Norway), Richard Loulou (Canada), Richard Richels (USA), Hector Segenovic (Argentina), Kenji Yamaji (Japan)

Contributing Authors:
Christoph Boehringer (Germany), Knut Einar Rosendahl (Norway), John Reilly (USA), Kirsten Halsnæs (Denmark), Ferenc Toth (Germany), ZhongXiang Zhang (Netherlands)

Review Editors:
Lorents Lorentsen (Norway), Oyvind Christopherson (Norway), Mordechai Shechter (Israel)

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