计算产品中的碳分子：解开不断增长的碳强度方法网（英）

Milan Elkerbout, Katarina Nehrkorn, and Brandon Holmes About the Authors Milan Elkerboutis a fellow and director of the International Climate Policy Initiativeat Resources for the Future (RFF), working on international climate policy and on the Katarina Nehrkornis a research associate at RFF whose research spans acrossinternational climate policy and industrial decarbonization. Nehrkorn earned her BAin economics from the University of Michigan, afterwards working at Deloitte’s Riskand Financial Advisory division for two years. In 2023, she completed her MSc in Brandon Holmesis a research analyst at RFF. Holmes earned his MSc in Environmentaland Natural Resource Economics at Durham University in the United Kingdom. About RFF Resources for the Future (RFF) is an independent, nonprofit research institution inWashington, DC. Its mission is to improve environmental, energy, and natural resourcedecisions through impartial economic research and policy engagement. RFF is Working papers are research materials circulated by their authors for purposes ofinformation and discussion. They have not necessarily undergone formal peer review.The views expressed here are those of the individual authors and may differ from those Sharing Our Work Our work is available for sharing and adaptation under an Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license. Youcan copy and redistribute our material in any medium or format; you must giveappropriate credit, provide a link to the license, and indicate if changes were made,and you may not apply additional restrictions. You may do so in any reasonablemanner, but not in any way that suggests the licensor endorses you or your use.You may not use the material for commercial purposes. If you remix, transform, or Abstract This is the second Resources for the Future (RFF) working paper on interoperabilityof carbon intensity quantification methods.1This paper connects the ongoing debateon carbon accounting methods with existing practices in lifecycle accountingand environmental product declarations. A case study compares carbon intensityquantification methods across the EU carbon border adjustment mechanisms, theUS Environmental Protection Agency’s labeling program, and an International Trade Contents 1. Introduction and Policy Context 2. From Counting to Accounting2.1. International vs Corporate Accounting 3. Relevant Policies We Consider 4. What Is Product-Level Accounting?4.1. What Is a Product?4.2. When Are Products Substitutes? 7 5. Allocating Emissions from Facilities to Products 5.1. Is Allocation Always Necessary?105.2. Definitions115.3. Four Forms of Allocation115.4. Other Allocation Challenges12Box 1. Recycling: How to Treat It – Module D Implications13 6. Case Study: Comparing the EU CBAM, EPA Labeling Program,and US ITC Study 15 6.1. Program Goals6.2. Emission Types6.3. System Boundaries6.4. Facility-Level Quantification Methodologies6.5. Allocation 7. Key Takeaways and Discussion 20 References Appendix 1. Life-Cycle Stages in EPDs A2.1. ISO 14067: Greenhouse gases — Carbon footprint of products — A2.4. ISO 14044: Environmental management – life cycle assessment –Requirements and guidelines A2.5. ISO 14040: Environmental Management—Life Cycle Assessment—Principles and Framework A2.6. ISO 21930: Sustainability in Buildings and Civil Engineering Works—Core Rules for Environmental Product Declarations of ConstructionProducts and Services 32 A2.7. ISO/TR 14069: Greenhouse Gases—Quantification and Reportingof Greenhouse Gas Emissions for Organizations—Guidance for theApplication of ISO 14064-1 A2.8. ISO 14064-1: ISO 14064-1:2018, Greenhouse Gases—Part 1: Specificationwith Guidance at the Organization Level for Quantification and Reporting of A2.9. ISO 14064-2: Greenhouse Gases—Part 2: Specification with Guidance atthe Project Level for Quantification, Monitoring and Reporting of Greenhouse A2.10. ISO 14064-3: Greenhouse Gases—Part 3: Specification with Guidancefor the Verification and Validation of Greenhouse Gas Statements34 1. Introduction and Policy Context Counting carbon—including how and why to do it—is garnering more attention inclimate policy. New policies that intersect climate, trade, sustainable finance, anddomestic manufacturing require carbon intensity metrics. Even as some countriesreappraise the pace at which climate policy should evolve, knowing how manymetric tons of greenhouse gases are associated with a product, service, company, In a working paper last year, we discussed this concept of interoperability (Elkerboutand Nehrkorn 2024). The Organisation for Economic Co-operation and Development’sInclusive Forum on Carbon Mitigation Approaches has also done significant workto identify challenges and potential solutions to calculating product-level carbonintensity metrics, including recent work comparing available datasets on carbonintensity (OECD 2024, 2025). In this second paper, we extend the analys