Reducing the vulnerability of the energy system can help safeguard the normal functioning of the economy and society and promote the transition to a green, low-carbon system, which in turn has a potential impact on the global greenhouse effect. To explore the causal relationship between energy vulnerability and CO₂ emissions, this study first constructs a composite energy vulnerability index (EVI) for empirical analysis based on a balanced panel dataset of 119 countries from 2000 to 2019. The study then examines the potential heterogeneity. Further, to investigate the impact mechanism, this study decomposes the total effect into scale effect, structural effect, and technology effect for detailed discussion. The main findings are: (1) decreased energy vulnerability can help curb CO₂ emissions, leading to a “win-win” situation; (2) significant heterogeneity exists in the relationship between EVI and CO₂ emissions; (3) decreased energy vulnerability can not only reduce CO₂ emissions directly, but also indirectly by lowering the total primary energy supply, promoting renewable energy use, and enhancing energy efficiency. In light of these findings, we offer specific recommendations for reducing energy vulnerability and limiting the greenhouse effect.

降低能源系统的脆弱性，有助于保障经济社会的正常运转，促进向绿色低碳系统转型，进而对全球温室效应产生潜在影响。_{为了探讨能源脆弱性与CO 2}排放之间的因果关系，本研究首先基于2000年至2019年119个国家的平衡面板数据集构建了一个综合能源脆弱性指数（EVI）进行实证分析，然后研究了潜在的异质性。此外，为了探讨影响机制，本研究将总效应分解为规模效应、结构效应和技术效应进行详细讨论。主要发现是：(1) 降低能源脆弱性有助于抑制 CO ₂排放，导致“双赢”局面；_{(2) EVI与CO 2}排放之间的关系存在显着异质性；(3)降低能源脆弱性不仅可以直接减少CO ₂排放，还可以通过降低一次能源供应总量、促进可再生能源利用、提高能源效率等方式间接减少CO 2 排放。根据这些发现，我们提出了降低能源脆弱性和限制温室效应的具体建议。