How to build an efficient blue carbon trading market in China? - A study based on evolutionary game theory

Carbon sequestration of blue carbon ecosystems worldwide is as high as 237.6 Tg C/a. China is one of the countries with the most resources of blue carbon, with carbon sequestration of 0.835 Tg C/a. To develop blue economy and facilitate the fulfillment of carbon neutrality, it is of great significance for China to build the blue carbon trading market (BCTM). This paper aimed to improve the participation probability of stakeholders to construct an effective BCTM through evolutionary game theory. First, we constructed a tripartite evolutionary game model including the governments, the suppliers of blue carbon (SBC) and the demanders of blue carbon (DBC), based on the corresponding cost and benefit in BCTM. To further reveal the factors affecting the cooperation of above parties, we analyzed the sensitivity of the stakeholders through five parameters, i.e., proportion of subsidies, unit carbon tax, blue carbon credits, unit price of blue carbon credits, and the cost of carbon emission reduction unit. To verify the game model, a case study of blue carbon credits of mangrove trading was performed. The main conclusions are as follows. In the initial stage of BCTM, the governments need to play a leading role in regulating and incentivizing motivation of the SBC and DBC. Subsidies and carbon taxes are conducive to promoting BCTM to develop into the middle stage. In the middle stage, price and quota of BC credits are two primary parameters to affect the evolutionary results of above three groups. Thus, it's necessary for the governments to adjust these parameters in time. When the trading scale and operation mode of BCTM approaching stable, the market will enter into the mature stage. Then, the governments can reduce subsidies to save fiscal expenditure and lessen the intervention, so as to gradually withdraw from the market. The above conclusions can provide a theoretical basis and reference for the construction of efficient BCTM and promote the integration of blue carbon into the carbon market in China.