<p>This study investigates the asymmetric linkages between climate finance, renewable energy consumption, economic and demographic growth, trade openness, and ecological footprint across ten developing Mediterranean economies from 2002 to 2021. Unlike prior work largely centered on carbon emissions, this paper uses the ecological footprint as a multidimensional sustainability metric, offering more reliable and comprehensive view of environmental pressures. Methodologically, the analysis applies the NARDL/PMG estimations, enabling the identification of both short- and long-run asymmetries while accounting for existing cross-country heterogeneities. Our findings reveal that climate finance is a significant mitigating factor, as 1% increase reduces ecological footprint by 1.6%. Renewable energy consumption exhibits asymmetric effects: sustained increases lower ecological footprint, while decreases exacerbate environmental degradation. In contrast, trade openness generates mixed impacts, with expansionary shocks intensifying ecological pressures and contractionary shocks reducing them. Country-specific short-run estimates further highlight heterogeneous responses across the region. Policy implications call for: (i) scaling up climate finance flows to support sustainable transitions, (ii) ensuring the stability of renewable energy development, and (iii) embedding environmental safeguards in trade frameworks. By combining an asymmetric econometric approach with a holistic sustainability indicator, this research contributes novel insights into the finance–energy–environment nexus in the Mediterranean context.</p> Graphical Abstract <p></p>