2015年-CEPS欧洲政策研究中心_An_Assessment_of_US_Progress_towards_its_Pledge_on_Climate_Change_Mitigation_16页_586kb

Summary of US Progress towards Climate Change Mitigation Pledge

Core Content

This document assesses the United States' progress towards its 2020 pledge to reduce greenhouse gas (GHG) emissions by 17% from 2005 levels, made by President Obama at the Copenhagen climate meeting in 2009. Despite the failure of Congress to pass comprehensive climate legislation, the report concludes that the U.S. is on track to achieve a reduction of 16.3% by 2020 under the current policy regime, which it refers to as the "Clean Air Act regime." This outcome is attributed to three key factors: greenhouse gas regulations under the Clean Air Act, secular trends in natural gas supply and energy efficiency, and sub-national policy efforts.

Main Points

1. Greenhouse Gas Regulation under the Clean Air Act

• The Clean Air Act grants the EPA authority to regulate GHGs, which was affirmed by the Supreme Court in 2007.
• The EPA has implemented regulations for mobile sources (e.g., vehicle fuel economy standards) and preconstruction permitting for stationary sources.
• The most significant uncertainty lies in the operating performance standards for existing stationary sources, which could mandate efficiency improvements or coal-to-natural gas substitution.
• These regulations are expected to reduce GHG emissions by 10.5% by 2020 compared to 2005 levels.

2. Secular Trends in Natural Gas Supply and Energy Efficiency

• Natural gas supply has increased, and prices have decreased, leading to a shift from coal to natural gas in electricity generation.
• Energy efficiency improvements have reduced the energy intensity of economic activity.
• These trends are expected to reduce CO₂ emissions in the electricity sector by 240 million tonnes by 2020, contributing to a 3.3% reduction in emissions from 2005 levels.

3. Sub-National Policy Efforts

• California and nine northeastern states have implemented cap-and-trade programs.
• Renewable Portfolio Standards (RPS) are in place in 29 states and the District of Columbia.
• Energy Efficiency Resource Standards (EERS) are implemented in 24 states.
• These sub-national policies are expected to contribute 2.5% of emissions reductions below 2005 levels.

Key Information

• The Clean Air Act regime is projected to result in 16.3% emissions reductions by 2020, which is close to the 17% pledged by President Obama.
• The Waxman-Markey cap-and-trade proposal, if enacted, would have led to 33.6% emissions reductions by 2020, but only 13.6% would have been domestic reductions, with the majority coming from offsets.
• The domestic emissions under the Clean Air Act regime are likely lower than under Waxman-Markey, due to the crowding out effect of the cap-and-trade system, which would have limited the effectiveness of other emissions reduction measures.
• The United States is expected to fail its financing commitments under the Copenhagen Accord, as the public contribution is insufficient and international offsets are not part of the Clean Air Act regime.

Uncertainties and Considerations

• The stringency and structure of EPA regulations, especially for existing stationary sources, remain the major source of uncertainty.
• The economic recession and energy efficiency investments have contributed to emissions reductions, but their impact is expected to diminish by 2020.
• Sub-national policies are increasingly important, but their effectiveness is limited under a national cap-and-trade system, as they may become non-binding or crowded out.

Conclusion

While the U.S. is close to meeting its domestic emissions reduction pledge, it is unlikely to meet its international financing commitments. The current policy mix, including the Clean Air Act, secular trends, and sub-national efforts, is more effective in reducing emissions than the cap-and-trade system that was proposed in 2010. This suggests that the status quo is achieving greater emissions reductions than the original legislative proposal.