States have historically been the primary drivers of climate change policy in the US, particularly with regard to emissions from power plants. States have implemented policies designed either to directly curb greenhouse gas (GHG) emissions from power plants, or to encourage energy efficiency and renewable energy growth. With the federal government withdrawing from the global climate agreement, understanding which state-level policies have successfully mitigated power-plant emissions is urgent. Past research has assessed policy effectiveness using data for periods before the adoption of many policies. We assess 17 policies using the latest data on state-level power-sector CO₂ emissions. We find that policies with mandatory compliance are reducing power-plant emissions, while voluntary policies are not. Electric decoupling, mandatory GHG registry/reporting and public benefit funds are associated with the largest reduction in emissions. Mandatory GHG registry/reporting and public benefit funds are also associated with a large reduction in emissions intensity.

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国家气候和能源政策在减少电力部门CO ₂排放方面的有效性

历史上，各州一直是美国气候变化政策的主要推动者，尤其是在发电厂的排放方面。各国已实施旨在直接抑制发电厂的温室气体（GHG）排放或鼓励能源效率和可再生能源增长的政策。随着联邦政府退出全球气候协议，了解哪些州级政策已成功减轻电厂排放量已成为当务之急。过去的研究使用许多政策通过之前的时期的数据来评估政策的有效性。我们使用有关国家级电力行业CO ₂的最新数据评估了17项政策排放。我们发现，具有强制性合规性的政策正在减少发电厂的排放，而自愿性政策却没有。电脱钩，强制性GHG注册/报告和公共利益资金与减少排放量最大有关。强制性的温室气体登记/报告和公益基金也与排放强度的大幅度降低有关。