This article describes a multi-echelon supply chain model with three supply chain players under neutrosophic fuzzy demand. By accurately forecasting customer demand and aligning inventory levels accordingly, companies can minimize excess inventory and reduce the need for additional production, transportation, and storage. This optimization helps to prevent unnecessary carbon emissions associated with the production, transportation, and warehousing of excess inventory. In order to maintain sustainability, carbon emission is controlled under each stage of the player. The production rate of the semi-finished as well as finished product is considered variable to maintain the flexibility of the manufacturing process. In addition, quality control is incorporated to improve the quality of the product manufactured and, furthermore, ensure that the products meet customer expectations and specifications. By reducing product failures and defects, customer satisfaction is improved, which leads to fewer returns, exchanges, and customer complaints. This reduces the environmental impact of reverse logistics and disposal of returned or defective goods. Also, the solution technique is carried over using the analytical methodology to prove the convexity of the objective function. The numerical verification is done to suit the proposed model with realistic cases. The sensitivity analysis is performed to show the effects of constant parameters. At last, managerial insights and some conclusions are given to address the exact outcome and identify measures to make better decisions.