Scientific measurement and analysis of the spatial and temporal distribution characteristics of agricultural carbon emissions (ACEs) and the influencing factors are important prerequisites for the formulation of reasonable ACEs reduction policies. Compared with previous studies, this paper fully considers the heterogeneity of rice carbon emission coefficients, measures and analyzes the spatial and temporal characteristics of ACEs in Jiangsu Province from three carbon sources, including agricultural land use, rice cultivation, and livestock and poultry breeding, and explores spatial clustering patterns and driving factors, which can provide a reference for agricultural low-carbon production. The results indicate that from 2005 to 2020, Jiangsu’s ACEs showed a decreasing trend, with an average annual decrease of 0.32%, while agricultural carbon emission density (ACED) showed an increasing trend, with an average annual increase of 0.16%. The area with the highest values for ACEs is concentrated in the northern region of Jiangsu, while the areas with the highest values for ACED are distributed in the southern region. The spatial clustering characteristics of ACEs have been strengthening. The “H-H” agglomeration is mainly concentrated in Lianyungang and Suqian, while the “L-L” agglomeration is concentrated in Zhenjiang, Changzhou, and Wuxi. Each 1% change in rural population, economic development level, agricultural technology factors, agricultural industry structure, urbanization level, rural investment, and per capita disposable income of farmers causes changes of 0.112%, −0.127%, −0.116%, 0.192%, −0.110%, −0.114%, and −0.123% in Jiangsu’s ACEs, respectively. To promote carbon emission reduction in agriculture in Jiangsu Province, we should actively promote the development of regional synergistic carbon reduction, accelerate the construction of new urbanization, and guide the coordinated development of agriculture, forestry, animal husbandry, and fisheries industries.

The construction and development of China’s forest cities revolves around the goal of building an environmentally friendly society and achieving harmonious development between human beings and nature, which is essentially the implementation of the concept of green development and helps promote the sustainable development of sustainable cities. Based on the panel data of 263 prefecture-level cities in China from 2001 to 2020, the National Forest City Policy (NFCP) is used as a quasi-natural experiment to assess the effect of NFCP on haze pollution management and their heterogeneity using a time-varying DID (difference-in-differences) model, and a mediating effect model is used to analyze the mechanism of the effect of NFCP on haze pollution. The research found that (1) the NFCP can reduce urban haze pollution, and this finding remained robust after placebo tests and the replacement of explanatory variables; (2) the NFCP is more conducive to reducing haze pollution in the Pearl River Delta urban agglomeration, Type II large cities, cities in the eastern region, and cities east of the Hu Huanyong line; (3) the NFCP will improve urban green space coverage, raise residents’ awareness of environmental protection, and promote the development of tertiary industries, thereby promoting urban haze reduction.

This paper measures and analyzes the characteristics of changes in agricultural carbon emissions, structure and intensity from 2005 to 2020 based on agricultural input-output data, explores the drivers of agricultural carbon emissions using the LMDI model, and uses the TAPIO decoupling model to explore the relationship between agricultural economic development and agricultural carbon emissions in Jiangsu province. The research indicate that: (1) From 2005 to 2020, the agricultural carbon emissions in Jiangsu Province showed a three-stage change of "decline - rise - decline", with an average annual decrease of 0.34%; Carbon emissions per 10,000 yuan of total agricultural output value decreased from 701.43 kg in 2005 to 215.96 kg in 2020, with an average annual decrease of 7.55%. (2) The factors of agricultural production efficiency, agricultural production structure and agricultural labor scale all contribute to agricultural carbon emission reduction to different degrees, while the factors of agricultural economic level and total population contribute to agricultural carbon emission reduction to different degrees. (3) The decoupling elasticity index of agricultural carbon emissions and agricultural economic level in Jiangsu Province lies between -3.3217 and 3.6546, and the decoupling types are mainly weak and strong decoupling. According to our research results, agricultural production efficiency should be improved, the structure of the plantation industry should be optimized, and the transfer of agricultural labor to secondary and tertiary industries should be promoted in order to promote high-quality development of agriculture.