Although there are many articles on carbon emission reduction of sustainable supply chain, most of them study the carbon emission reduction efficiency of supply chain in the case of single carbon policy or demand determination. Based on previous studies, this paper considered a supply chain consisting of a single manufacturer and a single retailer in an uncertain demand market. The effects of demand randomness and different carbon policies on carbon emission reduction level and optimal decision in supply chain were studied by constructing mean-variance utility function and Stackelberg game. Due to the difficulty of data acquisition, this paper verified the equalization results by numerical simulation. The results show that: (1) cap-and-trade policy, government subsidy policy and carbon tax policy can promote the carbon emission reduction investment of supply chain, while carbon tax policy will lead to the decline of the overall profit of supply chain; (2) For the manufacturer and the retailer, adopting a strategy with a low degree of risk avoidance will increase its own profits; (3) For the supply chain as a whole, it is more advantageous for manufacturers to adopt higher risk avoidance strategies, while retailers to adopt lower risk avoidance strategies. In addition, in the conclusion, this paper puts forward management implications related to stakeholders, thus providing help for the development of sustainable supply chain.

This paper discusses the impact of government intervention (greenness threshold limit) and cap-and-trade policy on green investment, stakeholder profits and social welfare under different power structure scenarios in the green supply chain. First, a two-level green supply chain system is constructed: a manufacturer that produces green products and complies with cap-and-trade policies and a retailer that sells green products. Based on the Stackelberg game and Cournot game, we compare the optimal solutions under the government intervention mechanism and cap-and-trade mechanism with manufacturer leadership, retailer leadership and equal power. The results are as follows: (1) both government intervention and the cap-and-trade mechanism are conducive to an increase in green technology innovation and profit, but excessive control will lead to a decline in social welfare. (2) The results in the concentrated scenario were better than those in the dispersed scenario. In the decentralized state, the result of equal power is the best, the result of retailer leadership is next, and the result of manufacturer leadership is the worst. (3) The lower cost of green investment will cause enterprises to give up purchasing carbon emission permits from the carbon market.

While carbon emissions reduction brings about environmental benefits, it can also create financial pressure on many manufacturing enterprises. Many manufacturing enterprises have begun to pledge their own carbon emissions right quotas for financing and the funds from this financing are being used to implement energy savings and emissions reduction strategies. To investigate the impact of carbon emissions right pledge financing on supply chains, this study constructed a two-echelon low-carbon supply chain, which consisted of a capital-constrained manufacturer and a retailer. The manufacturer invested in carbon reduction technologies using carbon emissions right pledge financing. On this basis, we analyzed the carbon emissions reduction levels and profits of the supply chain in three different power structures. The results showed that the manufacturer pledged the most carbon emissions rights to finance emissions reduction in the Nash model and, in this case, the carbon emissions reduction levels and profits of the supply chain were always the highest. In the manufacturer-led Stackelberg model, the overall economic and environmental benefits of the supply chain were the lowest. In addition, we analyzed the sensitivity of the important parameters of the model and revealed some management implications.