Spatial pattern and responsibility sharing of carbon transfer in China's inter-provincial grain trade

Abstract: The spatial pattern of carbon transfer is of practical significance for the responsibility sharing of carbon emission reduction. It is a high demand to explore the inter-provincial collaborative strategies of carbon emission reduction for food security. In this study, the inter-provincial grain trade and the carbon emission were calculated to determine the spatial transfer using the linear programming model of carbon emission in the grain trade. The cross-sectional data was selected from 31 provincial administrative regions in China in 2020. The distribution characteristics were analyzed for the carbon emission responsibility sharing of the grain trade in each province. The results were as follows: 1) In the carbon emission pattern of inter-provincial grain trade, the export areas were mainly distributed in the northeast, north, northwest, and central China, whereas, the import areas were mainly in the southwest, south, and east China. The total amount of grain trade was 1.53×108 t in China in 2020. Among the grain export areas, northeast, north, northwest, and central China transported 71.265 4, 26.173 8, 4.555 1, and 50.697 1 million tons, accounting for 46.7%, 17.1%, 3.0%, and 33.2% of the total trade volume, respectively. 2) The carbon emission of grain trade showed the flow pattern of "North carbon to South and China carbon to the west" in space, indicating the small flow from the south to the north and the east to the west. The national export areas of grain carbon emission included the Hebei, Shanxi, Inner Mongolia, Jilin, Heilongjiang, Anhui, Jiangxi, Henan, Hubei, Hunan, Gansu, Ningxia, and Xinjiang regions. The carbon emission flows of the grain trade in the north-south and east-west directions were 9 119.82×104, and 2 229.49×104 t, respectively. 3) The input area was needed to pay greater responsibility for the carbon emission reduction than the output area in the process of carbon emission transfer of grain trade. Economically developed provinces presented a relatively large share of responsibility, while those with smaller economies were relatively small responsibilities. There were 29.5% and 70.5% average proportions of carbon emission reduction shared by the output and the input area, respectively. 4) In the principle of shared responsibility, there was a low share proportion in Anhui, Heilongjiang, Jilin, Jiangxi, Inner Mongolia, Shanxi, and Xinjiang in the export areas, and the high share proportion was in Gansu, Hebei, Henan, Hubei, Hunan, and Ningxia. Influenced by the assistance effect, economically developed provinces provide more assistance to economically underdeveloped provinces and will assume more responsibility for emission reduction. In general, based on the principle of shared responsibility, it is not only conducive to controlling carbon emissions in export and import areas, but also plays a positive role in stabilizing the output of major grain producing areas. Therefore, the study puts forward targeted strategies to ensure regional food security and fair and reasonable distribution of carbon emission reduction responsibilities among regions, so as to achieve the win-win goal of "carbon neutral, carbon peak" strategy and food security.