This study investigates the impact of the CEO's origin, whether recruited internally or externally, on corporate carbon performance. The new corporate market trend has drawn attention to the board, as firms face growing pressure from environmental and governance bodies. This study, using a panel dataset of 10,252 firm-year observations from 1990 to 2023, found that internally appointed CEOs exhibit significantly lower carbon emissions than externally recruited CEOs. Our findings indicate that insider CEOs are associated with a 5.00% reduction in carbon emissions, which increases to 5.1% with stronger internal governance support and to 5.3% with greater external governance support, relative to outsider CEOs. This exchange is further strengthened in firms after accounting for firm-specific heterogeneity and correcting for endogeneity. Our study makes a significant contribution to corporate governance and firm-specific environmental strategy by showing that CEOs' origins, in conjunction with governance structures, play a significant role in shaping firms' carbon policies. In this regard, this study demonstrates not only that firms can make substantial improvements to reduce carbon pollution but also gain a competitive advantage for their long-term sustainability. By associating leadership with carbon performance, we highlight a novel aspect to debate on sustainability and executive decision-making. In positions of increasing regulatory and stakeholder scrutiny over corporate sustainability, the results aim to provide a practical understanding for boards of directors, whether firms recruit CEOs from insider or outsider sources. Recruiting experienced CEOs internally will strengthen the firm's capacity to achieve long-term carbon-reduction targets and sustain its practices.