The Belt and Road Initiative (BRI) is a central policy within China's regional development and foreign trade strategy. Traditional trade has typically depended on economic valuation of resources, while the embedded environmental value is rarely considered. This situation exists in most BRI trade evaluations. To address BRI environmental sustainability issues, we consider the role of pivotal Chinese provinces and their key trade partners (ASEAN countries) as an illustration for the environmental value of resource exchanges. Emergy accounting is used as the valuation tool for a sample period of seventeen years. Key results include: (1) Emergy valuations show sustainability of sample provinces decreased over time; (2) ASEAN countries such as Indonesia, Malaysia, Singapore, Thailand, and Vietnam play significant resource roles for provincial economic systems; (3) Diverse trends in trade between pivotal provinces and ASEAN countries resulted in an unbalanced trade structure from trade. Policy implications are proposed to promote a more globally sustainable and fair trade using BRI as an established trade policy.