可持续发展与国际关系研究所-大型新兴经济体深度脱碳的政策教训（英）-2021.11-86页_2mb

Summary of Policy Lessons on Deep Decarbonization in Large Emerging Economies

Core Content

This report presents an analysis of deep decarbonization pathways (DDPs) for Brazil, India, Indonesia, and South Africa. It outlines the key policy lessons and scenario results for each country, focusing on the feasibility and implications of achieving carbon neutrality by 2050 in line with the Paris Agreement. The report emphasizes the importance of integrating climate goals with broader sustainable development objectives and highlights the need for effective policy design and international cooperation to enable large-scale transitions.

Main Features of the Report

• Scenario Analysis: The report uses two main scenarios, the Current Policies Scenario (CPS) and the Deep Decarbonization Scenario (DDS), to evaluate emission trajectories and policy effectiveness.
• Country-Specific Insights: Brazil is the focus of this section, with detailed analysis of emission profiles, mitigation actions, and macroeconomic and social implications.
• Integrated Modelling Approach: A combination of six sectoral models and a Computable General Equilibrium (CGE) model (IMACLIM-BR) is used to simulate the impact of different policies and actions on GHG emissions and socio-economic outcomes.
• Policy Synergies and Trade-offs: The report highlights how decarbonization efforts can align with and sometimes conflict with national non-climate objectives, such as economic growth and poverty reduction.

Key Policy Lessons for Brazil

1. Combining Command-and-Control with Market Mechanisms

• Command-and-control policies, such as restricting access to public credits for non-compliant land use, are effective in reducing deforestation.
• These policies can achieve up to 59% of total cumulative GHG emission reductions by 2050.
• Carbon pricing complements these measures, with a significant contribution to mitigation efforts in various sectors.

2. Carbon Pricing as a Key Tool

• A carbon pricing mechanism, including a cap-and-trade system in industry and a carbon tax on fossil fuel combustion in other sectors, is crucial for achieving net-zero emissions.
• Carbon prices are expected to increase linearly, reaching 25 USD/tCO₂eq in 2030 and 65 USD/tCO₂eq in 2050.
• Revenues from carbon pricing are recycled back into the economy, with 100% of the funds used to reduce labor charges and support households, which helps in fostering employment and compensating low-income groups.

3. Sectoral Mitigation Actions

• AFOLU (Agriculture, Forestry and Land Use) is the most significant contributor to GHG emission reductions, with 179% of cumulative avoided emissions in the period 2021–2030 and 1042 MtCO₂eq in 2050.
• Land use change and forestry are central to achieving the emission reduction targets, with a 93% reduction in deforestation emissions in the DDS compared to CPS.
• Native vegetation restoration in public areas is more cost-effective and contributes significantly to cumulative avoided emissions.

4. Cost-Effectiveness of Mitigation Actions

• A large portion of emission reductions can be achieved at negative or low costs, particularly in sectors like modal shift in transport, energy efficiency in industry, and sustainable agricultural practices.
• The marginal returns of mitigation actions decline after a carbon price of 35 USD/tCO₂eq, indicating the need for more cost-effective pricing strategies.
• A carbon price trajectory of 25, 30, and 35 USD/tCO₂eq in each decade can achieve 87% to 94% of the DDS cumulative avoided emissions.

5. Macroeconomic and Social Implications

• The DDS leads to slightly better economic and social outcomes than the CPS, including higher GDP and GDP per capita, lower unemployment, and higher disposable income for the poorest households.
• The carbon pricing scheme increases domestic price levels, which affects the trade balance negatively but is mitigated by revenue recycling.
• The recycling of carbon revenues is socially progressive, as it increases disposable income for low-income households and supports job creation in labor-intensive sectors.

Key Findings

• The DDS results in 1.0 GtCO₂eq of emissions in 2030 and 17 MtCO₂eq in 2050, compared to 1.65 GtCO₂eq and 1889 MtCO₂eq under the CPS.
• Population growth is projected to increase from 210 million in 2019 to 233 million in 2050, with 86% of the population living in urban areas by 2050.
• GDP growth is expected to be 3.5% in 2021, 2.5% from 2021–2030, 2.25% from 2031–2040, and 2% from 2041–2050.
• Gini index decreases after the economic downturn, but at a slower pace than before.
• Disposable income for the poorest households increases significantly in the DDS, reflecting the benefits of revenue recycling and labor charge reductions.

Conclusion

The report underscores the need for a whole-of-society approach to decarbonization, emphasizing the role of policy coherence, sectoral integration, and international cooperation. It concludes that while technological advancements are essential, the political economy of implementation must be carefully managed to ensure equitable and effective transitions. The DDS demonstrates that deep decarbonization is not only feasible but also beneficial to economic and social development when supported by well-designed policies and revenue recycling mechanisms.