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Plastic pollution is currently one of the environmental pollution issues of global concern, and microplastics (plastics with a size ≤ 5 mm) have also attracted much attention due to their large specific area, higher pollutant adsorption capacity, and higher migration performance. As the population increases and more chemical products are manufactured, the level of microplastic pollution continues to increase. Microplastics discharged from sewage treatment systems will enter the ocean and rivers, so estuary ecosystems are vital to controlling marine microplastics. As the estuary of China's most significant river entering the East China Sea, the Changjiang River Estuary has become one of the typical areas for microplastic research in estuaries. This paper systematically reviews the sources, hazards, and impacts of microplastics in the Changjiang Estuary. Firstly, the research on microplastics in the Changjiang Estuary was analyzed, and we found that the bioaccumulation, removal, and interaction with microorganisms of microplastics have become a new research hotspot. At the same time, the current abundance of microplastics in the surface water of the Changjiang River Estuary is 1.71 ± 3.12 MP/L, which is lower than that of the Changjiang River area and the river farmland in Shanghai, but still higher than the 0.22 ± 0.27 MP/L in the area adjacent to the East China Sea. Microplastics smaller than 1000 μm accounted for 68% of the total, while transparent, white, blue, and black were the primary colors of microplastics in the Changjiang Estuary. In addition, polyethylene and polypropylene are the primary materials of microplastics in the central Changjiang River Estuary and related water bodies, and fibers are the main shape of microplastics. Industry, agriculture, domestic sewage, and air deposition may be the primary sources of microplastics in the Changjiang Estuary. The numerous lakes and water conservancy facilities in the Changjiang River Basin can reduce the number of microplastics reaching the Changjiang Estuary to a certain extent. At the same time, seasonal rainfall and ocean currents will affect the abundance of microplastics in the surface waters of the Changjiang River Estuary. Finally, this paper puts forward relevant suggestions based on the actual situation of the Changjiang River Estuary and the developed microplastic treatment technologies. This article will provide a structured reference for future research on microplastics in the Changjiang Estuary and assist in assessing microplastics' impact on the ecological environment. The Fate of Microplastic Pollution in the Changjiang River Estuary. [Display omitted] • Microplastics' sources, hazards, and impacts in the Yangtze Estuary were reviewed. • Bioaccumulation, removal, and interaction with microorganisms are the hotspots. • The microplastics in the water of the Changjiang mainly exists in the form of fibers. • Source control and establishment of MPs barriers will help to solve MPs pollution. [ABSTRACT FROM AUTHOR]

To achieve its carbon peak and neutrality targets, China is in need of balancing environmental and economic sustainability; In addition, whether environmental regulations can gain economic dividends while protecting the environment is particularly important. Based on the data of A-share listed companies in Shanghai and Shenzhen from 2012 to 2021, this study takes China's environmental fee-to-tax as a quasi-natural experiment, and adopts the difference-in-difference-in-differences model to evaluate the impact of environmental tax on enterprises' total factor productivity (ETFP). The results show that the environmental fee-to-tax significantly hinders the growth of ETFP. Further, this negative impact mainly stems from the fact that the reform prompts enterprises to choose strategic innovation and conduct greenwashing behavior. Furthermore, when considering enterprises' heterogeneity, we find that enterprises with large scale, high investment efficiency, state ownership, high market competitiveness and located in western regions are more resistant to policy shocks. This paper provides reliable empirical evidence and useful policy implications for further formulating environmental tax policies to accomplish the "win-win" goal for both the environment and the economy. [ABSTRACT FROM AUTHOR]

Nationwide unification of carbon emission right market in China has long been proposed yet not achieved. Launching of the nationwide trading center at Shanghai was a recent great step towards this target but the regional pilots covering respective zones are still in operation. With all trading data in those markets from their inceptions, this paper investigates the development status and trend of each submarket, based on which, it is revealed that sudden replacement of regional markets by the unified nationwide trading center is infeasible at the present stage, furthermore, feasibility of market merging is analyzed and optimized route for essential unification is designed. This paper contributes to deconstruct the value of carbon emission right and interprets its properties of option value, the equivalence of which value from the perspective of financial investment and enterprise operations is explored and formally established. Applying the geometric Brownian motion and optimal stopping time to model the carbon asset operation, option value of carbon emission right is estimated and marginal return-ability of its consumption is calculated for each region. Based on the analysis regionally, market merging is simulated and optimized route for nationwide market unification is proposed with policy suggestions. [ABSTRACT FROM AUTHOR]