隨著全球氣候變遷問題日益嚴重，企業的碳排放引起了投資者的廣泛關注，自從巴黎協定簽署後，各國政府加強了對企業碳排放的監管力度，也連帶影響了企業的資金成本。因此，本研究旨在探討碳排放對美國上市公司資金成本的影響。本研究使用2005年至2022年的美國上市公司碳排放數據，分析其對權益資金成本、債務資金成本以及加權平均資金成本的影響。實證結果顯示，範疇一和範疇二碳排放以及範疇一碳密度均顯著增加企業的資金成本。此外，本研究利用傾向分數配對和雙重差分法，分析巴黎協定後高碳排放企業之資金成本是否與低碳排放於統計上有顯著差異。部分實證結果顯示，在巴黎協定實施後，高碳排放企業的資金成本相較於低碳排企業有顯著差異。

As global climate change issues become increasingly severe, corporate carbon emissions have drawn widespread attention from investors, particularly affecting the performance of high-carbon-emitting companies in the capital market. Since the signing of the Paris Agreement, governments worldwide have strengthened regulations on corporate carbon emissions, subsequently influencing companies' cost of capital. This study aims to explore the impact of carbon emissions on the cost of capital for U.S. listed companies. Using company data on carbon emissions from 2005 to 2022, the study analyzes the effects on the cost of equity, cost of debt, and weighted average cost of capital (WACC). The empirical results indicate that both Scope 1 and Scope 2 carbon emissions, as well as Scope 1 carbon intensity, significantly increase the cost of capital for companies. Additionally, utilizing propensity score matching and difference-in-differences methods, the study examines whether the cost of capital for high-carbon-emitting companies differs significantly from that of low-carbon-emitting companies after the Paris Agreement. Some empirical results suggest that, following the implementation of the Paris Agreement, there is a significant difference in the cost of capital between high-carbon-emitting and low-carbon-emitting companies.

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