Modeling the Risks of Green Financing Water-Energy-Food Nexus Projects in BRICS Countries

The conceptual foundation of this study is that a country’s exposure to risk when using green bonds as a mechanism for financing sustainable development is shaped by a combination of macroeconomic, market, and social factors. This paper develops and empirically validates a fuzzy-set model to assess national-level risks associated with green financing projects within the Water–Energy–Food (WEF) Nexus in BRICS countries. Building on established theoretical frameworks and empirical evidence, the study conceptualises risk as a function of economic development, the scale of the domestic green bond market, institutional trust, and performance on the Multidimensional Poverty Index (MPI). The study employs fuzzy-set modelling to integrate these heterogeneous indicators into a unified quantitative risk score. This approach enables cross-country comparison and captures the non-linear nature of relationships between socio-economic and institutional factors. The country sample includes Brazil, Russia, India, and China, which have successively chaired the BRICS association between 2021 and 2025, thereby ensuring methodological consistency and representativeness. The empirical results reveal a clear stratification of green-finance risk levels across the four economies: China demonstrates the lowest risk (Y = 0.243), followed by Russia with a below-average risk (Y ≈ 0.41), while India (Y = 0.53) and Brazil (Y = 0.51) exhibit the highest relative risks. These outcomes highlight the critical role of institutional trust and market maturity in reducing financing uncertainty within the WEF nexus. The study contributes to the literature by integrating macroeconomic, social, and institutional indicators into a unified fuzzy-logic model of green-finance risk; offering a transparent methodology for country-level comparison; and providing policy insights for improving the enabling environment for green bond markets in emerging economies.