世界经济论坛-增加气候雄心：国际碳价格下限分析（英）-2021.11-38页_6mb

Summary of the World Economic Forum and PwC Insight Report on the International Carbon Price Floor (ICPF)

Core Content

This report analyzes the potential impact of an International Carbon Price Floor (ICPF) as a mechanism to accelerate global emissions reductions and support a just transition to a net-zero world. It explores how an ICPF could be implemented across different economies and sectors, and evaluates its economic and environmental implications in the context of the COP26 negotiations.

Main Questions Addressed

The report seeks to answer three key questions:

1. Can the ICPF significantly reduce emissions?
   Yes. The ICPF is projected to reduce global GHG emissions by 9.5% to 12.3% by 2030, depending on the scope of implementation.

2. Can it be done without severe economic damage?
   Yes. The economic impact of the ICPF is estimated to be less than 1% of global GDP, which could be offset by the redistribution of revenues.

3. Can it prevent the shift of emissions to other countries (carbon leakage)?
   Yes. The ICPF is designed to limit carbon leakage by providing a minimum carbon price, reducing the incentive for industries to relocate to countries with lower emission costs.

Key Findings

• The ICPF is a minimum carbon price that would be set at $75/mtCO₂e for high-income countries, $50/mtCO₂e for middle-income countries, and $25/mtCO₂e for low-income countries (in 2018 dollars).
• Emissions reductions would be most significant in major emitting countries such as:
  • India: 7.7% reduction in emissions.
  • United States: 11.1% reduction.
  • China: 16.8% reduction.
• The global GDP contraction due to the ICPF is estimated to be 0.1% to 0.6%, depending on the scope of implementation.
• The costs avoided by reducing emissions, such as damage from climate change, could offset or even eliminate the economic losses from the ICPF.
• Revenue generation from the ICPF could be as high as 3% of GDP in some regions and could be used to support households and industries through carbon dividends or tax reforms.

Advantages of the ICPF

• Flexibility: The ICPF can be implemented through existing carbon pricing mechanisms such as carbon taxes or ETSs.
• Transparency: Carbon prices are publicly observable, making it easier to monitor and enforce compliance.
• Mitigation of carbon leakage: Unlike tariffs, the ICPF encourages emission reductions without shifting economic activity.
• Global linkage of ETSs: Countries with ETSs could expand their systems to allow cross-border trading, creating a more unified carbon pricing approach.
• Simpler implementation: A minimum carbon tax is a straightforward method, though it may face political resistance.
• Carbon club: A complementary approach using tariffs to discourage non-participation, though it is less flexible than the ICPF.

Economic Models and Scenarios

• The analysis includes 10 scenarios that vary in the number of regions, sectors, and gases included.
• The CGE (Computable General Equilibrium) model is used to simulate the economic impacts of the ICPF, taking into account how changes in carbon pricing might influence prices, households, and businesses.
• EE MRIO (Environmentally Extended Multi-Regional Input-Output) model is used to assess the impact of the ICPF on high-emitting manufacturing industries (HEIs), particularly those at risk of carbon leakage such as cement, steel, and aluminium.

Challenges and Considerations

• The ICPF would require phased implementation between 2022 and 2030 to allow for adaptation.
• Low-income countries may need financial and technical support to participate effectively.
• The just transition is a central concern, with the report emphasizing the need for revenue redistribution to protect vulnerable populations.
• The core scenario includes all territories and major GHGs but is limited to HEI+ industries, which account for 51% of global emissions.

Conclusion

The ICPF represents a promising approach to increase global climate ambition, reduce emissions, and support a fair transition. While it has the potential to limit carbon leakage and stimulate economic growth, its success depends on international cooperation, policy design, and revenue distribution mechanisms. The findings aim to inform discussions at COP26 and provide a baseline for future policy development.

Glossary and Further Information

• HEI+: High-emitting manufacturing industries plus power generation and fossil fuel extraction/refining.
• CGE Model: A tool used to simulate the economic effects of policy changes.
• EE MRIO Model: A model that accounts for environmental and regional impacts of emissions policies.
• Carbon Dividend: A mechanism to redistribute ICPF revenues to households.
• NDCs: Nationally Determined Contributions under the Paris Agreement.
• CBAM: Carbon Border Adjustment Mechanism proposed by the EU to prevent carbon leakage.

The report is based on economic models and scenario analysis, with further technical details provided in the Technical Addendum.