AUTHOR=Rhouma Ali , Daher Bassel , Vrachioli Maria , Mohtar Rabi , Gil José M. TITLE=Financing the Water-Energy-Food-Ecosystem Nexus project: challenges, opportunities, and pathways for sustainable investment JOURNAL=Frontiers in Sustainable Resource Management VOLUME=Volume 4 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/sustainable-resource-management/articles/10.3389/fsrma.2025.1590161 DOI=10.3389/fsrma.2025.1590161 ISSN=2813-3005 ABSTRACT=The Water-Energy-Food-Ecosystem (WEFE) Nexus framework provides a holistic approach to sustainable resource management, addressing the interdependencies between these sectors to enhance resilience against climate change and resource scarcity. Despite its potential, financing WEFE projects remains a significant challenge due to complex investment structures, long-term payback periods, and difficulties in demonstrating economic returns. This paper explores innovative financing mechanisms, including climate finance, blended finance, and public-private partnerships (PPPs), which are essential for overcoming these financial barriers. It highlights the need for de-risking investment, ensuring regulatory clarity, and integrating standardized financial metrics to attract private-sector engagement. Several successful WEFE financing case studies illustrate the effectiveness of different investment approaches. The Climate Investor Two model, which combines public, private, and donor capital, has successfully supported renewable energy for irrigation, desalination, and water infrastructure projects in climate-vulnerable regions. Similarly, the Noor Ouarzazate Solar Complex in Morocco, a PPP-funded renewable energy and water efficiency project, demonstrates how government-backed risk-sharing mechanisms can mobilize large-scale private investment. Nature-based financial instruments, such as green bonds, resilience bonds, and Payment for Ecosystem Services (PES), have proven effective in promoting sustainable land management and watershed conservation. Despite these advancements, challenges such as fragmented governance, lack of standardized investment criteria, and perceived financial risks continue to hinder widespread WEFE financing. Addressing these gaps requires clear regulatory frameworks, performance-based financial incentives, and integrated risk mitigation mechanisms. This article underscores the critical role of blended finance, insurance-backed risk-sharing, and policy-driven financial incentives in ensuring long-term sustainability and scalability of WEFE projects. By strengthening financial instruments and aligning them with climate resilience and sustainability goals, WEFE investments can drive socioeconomic development while safeguarding essential ecosystem services.