【摘要】 根据《巴黎协定》共同时间框架，2025年前各缔约方要提交面向2035年的新一轮国家自主贡献（NDC）。2035年的减排雄心将是连接当前NDC与长期碳中和承诺的重要纽带，对全球能否最终实现2℃/1.5℃温升控制目标具有重要意义。该研究聚焦美国、欧盟这两个碳排放量最大的发达经济体和中国、印度这两个碳排放量最大的新兴经济体，从衔接NDC与碳中和承诺的角度预估四大排放体2035年潜在的碳减排力度，并利用碳配额分配体系和可计算一般均衡模型探究对2℃/1.5℃支持情况以及减排经济代价。结果显示：(1)从NDC迈向碳中和，2035年中国单位GDP二氧化碳排放可能比2005年下降73%～77%，美国碳排放可能比2005年下降61%～67%，欧盟碳排放可能比1990年下降65%～70%，印度单位GDP二氧化碳排放可能比2005年下降51%～58%。(2)上述碳减排力度有可能支持全球2035年走上2℃温控目标碳排放路径，但若要支持走上1.5℃路径，美国和欧盟2035年要达到零碳乃至负碳排放，中国碳排放要降至50亿t左右。(3)在不合作情景下，2035年中国实现上述碳减排力度面临的GDP损失为0.36%～0.58%，与美国（0.36%～0.52%）相当，略低于欧盟（0.49%～0.80%），印度所处发展阶段相对滞后，GDP损失更易受碳减排力度影响（0.26%～0.81%）；增强合作有助于以更低的经济代价实现碳减排，2035年四大排放体整体GDP损失有望从0.39%～0.65%下降至0.21%～0.41%。建议尽快深化面向2035年减排目标和实施路径的研究，进一步推动国家间应对气候变化合作交流，以助力全球实现巴黎气候目标。更多还原

【Abstract】 According to the common time frame of the Paris Agreement, all parties are expected to submit a new round of Nationally Determined Contributions(NDCs) for 2035 by 2025. Their carbon reduction efforts for 2035 will be a crucial link between the current NDCs and long-term commitments to carbon neutrality and will be of great significance to whether the world can ultimately achieve the temperature-control goal of 2 °C/1.5 °C. This study examines the United States(U.S.) and the European Union(EU), the two largest carbon-emitting developed economies, along with China and India, the two largest carbon-emitting emerging economies. The aim is to infer their potential carbon reduction efforts in 2035 from the perspective of bridging NDCs and carbon neutrality pledges. This study also explores the support for the 2 °C/1.5 °C goal and the economic costs of such efforts using a carbon allowance allocation framework and a computable general equilibrium model. The results show that:(1) Moving from the NDCs toward carbon neutrality, China′s carbon emissions per unit of GDP in 2035 could decline by 73%～77% from 2005, the U.S. carbon emissions could decline by 61%～67% from 2005, the EU carbon emissions could decline by 65%～70% from 1990, and India′s carbon emissions per unit of GDP could decline by 51%～58% from 2005.(2) These carbon reduction efforts may support a 2 °C-consistent global carbon emissions pathway in 2035. However, to support a 1.5 °C-consistent global pathway, the U.S. and the EU would have to achieve zero or even negative carbon emissions in 2035, and China would have to reduce its carbon emissions to about 5 Gt CO2.(3) In a non-cooperation scenario, China would face a GDP loss of 0.36%～0.58% in 2035 to achieve the above carbon reduction efforts, which is comparable to that of the U.S.(0.36%～0.52%) and slightly lower than that of the EU(0.49%～0.80%). Being at a relatively lagging stage of development, India would have a GDP loss(0.26%～0.81%) more susceptible to carbon reduction efforts. Enhancing cooperation can help achieve carbon reductions at lower economic costs, and the overall GDP loss of the four emitters is expected to decrease from 0.39%～0.65% in a non-cooperation scenario to 0.21%～0.41% in a cooperation scenario. It is suggested that China promptly deepens research on emission reduction efforts and implementation pathways for 2035 and further promotes transnational cooperation and exchanges in addressing climate change, thereby supporting the globle achievement of the Paris climate goals.更多还原