Zhao Alicia, O'Keefe Kowan T V, Binsted Matthew, McJeon Haewon, Bryant Adriana, Squire Claire, Zhang Mengqi, Smith Steven J, Cui Ryna, Ou Yang, Iyer Gokul, Kennedy Shannon, Hultman Nate
Center for Global Sustainability, University of Maryland, College Park, MD USA.
Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD USA.
NPJ Clim Action. 2024;3(1):63. doi: 10.1038/s44168-024-00145-x. Epub 2024 Jul 24.
Under the next cycle of target setting under the Paris Agreement, countries will be updating and submitting new nationally determined contributions (NDCs) over the coming year. To this end, there is a growing need for the United States to assess potential pathways toward a new, maximally ambitious 2035 NDC. In this study, we use an integrated assessment model with state-level detail to model existing policies from both federal and non-federal actors, including the Inflation Reduction Act, Bipartisan Infrastructure Law, and key state policies, across all sectors and gases. Additionally, we develop a high-ambition scenario, which includes new and enhanced policies from these actors. We find that existing policies can reduce net greenhouse gas (GHG) emissions by 44% (with a range of 37% to 52%) by 2035, relative to 2005 levels. The high-ambition scenario can deliver net GHG reductions up to 65% (with a range of 59% to 71%) by 2035 under accelerated implementation of federal regulations and investments, as well as state policies such as renewable portfolio standards, EV sales targets, and zero-emission appliance standards. This level of reductions would provide a basis for continued progress toward the country's 2050 net-zero emissions goal.
在《巴黎协定》下一个目标设定周期内,各国将在未来一年更新并提交新的国家自主贡献(NDC)。为此,美国越来越有必要评估实现新的、雄心勃勃的2035年国家自主贡献的潜在途径。在本研究中,我们使用一个具有州级细节的综合评估模型,对联邦和非联邦行为体的现有政策进行建模,包括《降低通胀法案》、《两党基础设施法》以及关键的州政策,涵盖所有部门和气体。此外,我们制定了一个高雄心情景,其中包括这些行为体的新政策和强化政策。我们发现,到2035年,相对于2005年的水平,现有政策可将温室气体净排放量减少44%(范围为37%至52%)。在加速实施联邦法规和投资以及州政策(如可再生能源组合标准、电动汽车销售目标和零排放电器标准)的情况下,高雄心情景到2035年可实现高达65%(范围为59%至71%)的温室气体净减排。这种减排水平将为该国实现2050年净零排放目标的持续进展提供基础。