Life Cycle Assessment is the primary approach to quantify the environmental impacts of plastics. However, it encounters challenges in allocating the impacts of respective stages to stakeholders, especially for systems involving multi-cycles and end-of-life stages. This study proposes a framework integrating Cooperative Game Theory to assess and allocate the greenhouse gas footprint among stakeholders. The applied concepts are the Shapley Value, Nucleolus and Core. The applicability is demonstrated by a case study of polyethylene terephthalate (PET) with four recycling and landfill scenarios. The Shapley Value, which highlights fair allocation, suggests ∼ 792–1164 kg of unburdening CO₂eq/t PET (∼ 47 % net recycling credits) assigned to material producers, 844.5–1216.5 kgCO₂eq/t PET to product manufacturers, and the remaining ∼ 2–3 % to users. The Nucleolus stresses satisfactory results in 1531.5–2275.5 kgCO₂eq/t PET to material producers, constituting ∼ 90 % of the total credits. The allocation does not change the total footprints; however, it is essential for the stakeholders’ cooperation in environmental initiatives.

生命周期评估是量化塑料环境影响的主要方法。然而，在将各个阶段的影响分配给利益相关者时遇到了挑战，特别是对于涉及多周期和生命周期结束阶段的系统。本研究提出了一个整合合作博弈论的框架，以评估和分配利益相关者之间的温室气体足迹。应用的概念是 Shapley 值、核仁和核心。通过聚对苯二甲酸乙二醇酯 (PET) 四种回收和填埋场景的案例研究证明了其适用性。强调公平分配的沙普利值建议将约 792–1164 kg 的 CO ₂ eq/t PET（约 47% 净回收信用额）分配给材料生产商，将 844.5–1216.5 kgCO ₂ eq/t PET 分配给产品制造商，以及剩余的 ∼ 2-3% 给用户。Nucleolus 向材料生产商强调 1531.5–2275.5 kgCO ₂ eq/t PET 的令人满意的结果，占总信用额的 ∼ 90%。分配不会改变总占用空间；然而，利益相关者在环境倡议中的合作至关重要。