碳排放風險對企業信用風險與資本結構之影響研究

Abstract

在全球氣候變遷與碳中和政策推動下，碳排放風險（以下或稱碳風險）已成為企業面臨的重要議題，並對企業之信用風險與資本結構決策產生深遠影響。過往研究多聚焦於碳風險對市場評價與股價波動之影響，對企業財務策略與槓桿行為的系統性探討仍較為稀缺。因此，本研究嘗試填補此一研究缺口，從信用風險與資本結構的雙重視角切入，探討碳風險對企業財務決策之影響機制。本研究旨在分析碳排放密度對企業信用風險指標與負債槓桿比率之影響，並進一步探討企業運用綠色金融工具是否具有調節碳風險影響之效果。本研究以2019至2023年期間，台灣上市櫃（去除金融業）企業為樣本，採信用風險指標及多項槓桿比率作為應變數，將碳排放密度作為主要自變數，並納入碳排放密度與發行綠債及永續債佔資產比之交乘項作為調節變數，實證方法採用OLS、固定效果與隨機效果模型，並進一步將樣本依制度導向、實務應用與數值型三種分組邏輯進行迴歸分析，以提升研究穩健性及交叉驗證整體完整性。實證結果顯示，碳排放密度與企業信用風險呈顯著正相關，意即碳風險越高的企業，其違約風險也會隨之上升。此外，碳排放密度與高碳排企業之整體負債比呈現顯著負相關，反映這類企業為降低財務風險與融資成本，傾向採取較為保守的槓桿策略。另一方面，企業若能有效運用綠色金融工具，提升其綠債與永續債發行比率，則可有效弱化碳風險對資本結構之負面影響，此一調節效果在整體槓桿比率與長期負債比率等多項財務指標中均具統計顯著性。分組實證則進一步發現，不同碳排產業之財務決策行為存在顯著差異性，其中高碳排產業對碳風險反應最為敏感。

In response to global climate change and carbon neutrality policies, carbon emission risk (hereafter known as carbon risk) has become a critical issue for firms, significantly influencing credit risk and capital structure decisions. While prior studies have mostly focused on market valuation and stock volatility, fewer have explored how carbon risk affects corporate financial strategies and leverage behavior. This study addresses this gap by adopting a dual perspective—credit risk and capital structure—to explore the mechanisms through which carbon risk influences firms’ financial decision-making.This research examines the impact of carbon intensity on corporate credit risk and leverage ratio, and whether green financial instruments moderate this relationship. Using data from Taiwan’s listed (non-financial) companies from 2019 to 2023, this study adopts OLS, fixed effects, and random effects models. The main explanatory variable is carbon intensity, with credit risk indicators and multiple leverage ratios as dependent variables. An interaction term between carbon intensity and the ratio of green and sustainable bonds to total assets is included to test for moderating effects. Subgroup regressions based on institutional, practical, and numerical criteria are conducted to enhance robustness.Empirical results show that carbon intensity is positively associated with credit risk and negatively related to total leverage ratio in high-emission firms, suggesting more conservative financing strategies. The moderating effect of green finance is significant, especially in reducing the negative impact of carbon risk on total and long-term leverage. Further analysis reveals that financial decision-making varies across industries, with high-emission sectors responding more sensitively to carbon risk.