The growing complications and inconsistencies in sustainable development evaluations require refined decision-making approaches that analyze vagueness in expert opinions. This research focuses on potential strategies to promote proactive environmental behaviours. This study introduces the algebraic operational laws for interval-valued complex spherical fuzzy soft sets (IVCSFSS) by incorporating membership, neutral membership, and non-membership grades. Also, we extend these laws to the interval-valued complex spherical fuzzy soft weighted average (IVCSFSWA) and interval-valued complex spherical fuzzy soft weighted geometric (IVCSFSWG) operators, along with their properties. A novel multi-criteria group decision-making (MCGDM) technique is developed using the proposed operators. The proposed model facilitates the evaluation of alternatives across various environmental sustainability components, including air quality, biodiversity, land and agriculture, and renewable energy resources. The comparative analysis demonstrates that the IVCSFSS-based methodology outperforms traditional fuzzy and soft set approaches, offering greater flexibility and accuracy in handling environmental sustainability decision problems. The results highlight the applicability of this approach for business, government, and policy decision-makers seeking to address environmental challenges.
Ali et al. (Wed,) studied this question.