As global environmental concerns intensify, identifying the key drivers of CO emissions (COe) becomes vital, particularly for high-energy-consuming nations. The present study delves into the impacts of green trade (GT), energy efficiency (EF), research and development (R&D), economic growth (EG), financial expansion (FE), and population density (PD) on COe across the top 20 energy-consuming countries from 2000 to 2022. We introduce three key innovations: (i) a novel environmental governance index (EGI), constructed using a distance-based and time-sensitive method, capturing governance progress under best- and worst-case trajectories; (ii) GT as a direct mitigation pathway, shifting the focus from aid-driven environmental finance to market-linked, credit-based green investment; and (iii) a refined approach to EF, highlighting reductions in carbon intensity per unit of economic output. Using the cross-sectionally augmented autoregressive distributed lags model, our findings highlight that GT and EF consistently mitigate COe in both the short and long run, while EG positively impacts COe. R&D and EGI effectively curb COe only in the long run, whereas FE and PD increase emissions. Notably, EGI moderates these relationships-dampening the adverse effects of EG, FE, and PD, while amplifying the mitigating impact of GT, EF, and R&D. These results are further validated through the common correlated effects mean group and augmented mean group methodologies, reinforcing the consistent influence of these factors on COe. The findings offer targeted, institution-sensitive policy recommendations for achieving environmental sustainability.