Impact of Technology Innovation, Renewable Energy and Foreign Direct Investment on Environment in BRICS Economies

Purpose: This study scrutinizes the effects of technological innovation, foreign direct investment (FDI), renewable energy, and economic growth on CO₂ emissions in the BRICS economies over the period 2000–2024.Design/Methodology/Approach: Unlike conventional mean-based approaches, the study employs the Method of Moments Quantile Regression (MMQR) to capture heterogeneous effects across different levels of carbon emissions.Findings: The MMQR estimates reveal that technological innovation significantly reduces CO₂ across all quantiles, although its mitigating effect weakens toward higher emission levels. Similarly, FDI exerts an adverse effect on CO₂ throughout the conditional distribution, supporting the pollution-halo hypothesis, while its environmental benefits diminish at higher emission levels. Renewable energy has a progressively stronger negative effect as the CO₂ distribution moves toward higher quantiles, highlighting its increasing importance for high-emission economies. In contrast, economic growth generally increases CO₂ emissions, although its marginal effect declines across higher quantiles. The Dumitrescu–Hurlin causality results indicate unidirectional causality from CO₂ emissions to technological innovation, while FDI and renewable energy causally affect CO₂ emissions. Furthermore, bidirectional causality exists amid GDP and CO₂ emissions.Implications/Originality/Value: The findings underscore the importance of green technological innovation, environmentally oriented FDI, renewable-energy expansion, and low-carbon growth strategies for achieving sustainable development in BRICS countries.