<p>Previous research has largely overlooked whether government intervention hinders or encourages environmentally sustainable practices in the pursuit of high economic growth. This study aims to close this gap by examining the potential effects of government fiscal tools, such as revenue collection management and green initiative funding, on the connection between CO₂ emissions and financial inclusion. Trade accessibility and other important characteristics are incorporated into the analysis of data collected from N-11 developing nations from 1990 to 2022. Furthermore, this research uses the Quantile Autoregressive Distributed Lag (QARDL) method technique to examine the dynamic both short and longterm correlations among different factors. The direction of causation is investigated using the panel of variables Quantile causality test, which verifies that changes in one variable influence changes in another. The empirical findings demonstrate that fiscal policy effectively reduces CO₂ emissions at higher quantiles (0.70–0.90). Fiscal policy’s impact on reducing emissions is greatest at these higher quantile levels and becomes negligible at the lower and middle quantiles (0.10–0.60). On the other hand, the findings show that environmental sustainability is hampered by rapid urban population increase, economic expansion, and trade openness. According to the quantile causality test, CO₂ emissions can both affect and be affected by shifts in fiscal policy, economic progress, and population size. These findings provide crucial insights for the Next-11 emerging economies, which are facing the triple challenges of economic stagnation, financial instability, and environmental degradation.</p>