2025-09-01-世界银行-碳边界调整机制（CBAM）暴露指数方法说明（英）页_26页_1mb

CBAM Exposure Indices: Methodology and Findings

The EU Carbon Border Adjustment Mechanism (CBAM) aims to mitigate carbon leakage by applying a carbon price to imports, aligned with the EU Emissions Trading System (EU ETS). This methodological note explains the index for assessing developing economies' exposure to CBAM through excess carbon payments relative to EU producers.

Methodology:

1. Emission Intensity & Trade Data: Uses GTAP-CE database for global analysis. Emission intensity (CO2e per unit value) is combined with CBAM sector coverage (aluminum, cement, iron & steel, fertilizers). Trade data (WITS/BACI) provides EU trade dependence.
2. Exposure Indices:
   • Trade Exposure Index (TEI): Excess carbon payments relative to EU producers as a share of a country's exports in a specific sector.
   • Aggregate Trade Exposure Index (ATEI): Sum of sectoral TEIs, representing excess payments across all sectors relative to total exports.
   • Output Exposure Index (OEI): Excess carbon payments relative to sectoral gross output.
   • Economic Exposure Index (EEI): Excess carbon payments relative to national GDP.
3. Calculation: Based on average carbon prices (USD 100/tonne CO2e), sector-specific emission differences, and trade characteristics. Reports assume costs fall on exporters.

Key Findings:

• High exposure countries/sectors identified: Mozambique (aluminum, ~7%); Egypt (iron/steel ~16%, fertilizers ~19%); Belarus (cement ~27%).
• Countries with relatively low excess payments: Ghana, Jordan, Morocco, and some EU peers.
• Overall aggregate (ATEI) trade exposure is low (<2% of exports for most), except Egypt (~16%).
• Macroeconomic impacts are small, though some countries experience competitiveness challenges (e.g., Mozambique's EEI is 0.6%). Cleaner exporters benefit, emission-intensive ones lose competitiveness.

Limitations:

• Data granularity, assumptions on cost allocation (exporter vs importer), methodology variations, dynamic emissions, and the exclusion of compliance costs.

**Source:** World Bank Methodological Note, 2025