Spatiotemporal pattern and coordinating development characteristics of carbon emission performance and land use intensity in the Yangtze River Delta Urban Agglomeration

Urban areas contribute about 75% of global carbon emissions in only about 2% of the world's total land area. A significant contributor of urban areas accounts for global climate change. It is necessary to scientifically explore the coordinating development characteristics between urban carbon emission and land use in recent years. An important way is seeking to determine the parallel path between rational land resource use and low carbon & emission reduction in cities, in order to promote the carbon neutrality goals at the basic level. Taking the Yangtze River Delta Urban Agglomeration as the study area, this study aims to analyze the coordinating development mechanism between carbon emission performance and land use intensity. The super-efficient slacks-based measure (SBM) model was also used to measure the carbon emission performance of each city from 2003 to 2018. The land use intensity of each city was then assessed to determine the spatial-temporal evolution pattern using continuous data on land use. The coordination model was utilized to reveal the coordinating development characteristics and dynamic evolution trend of carbon emission performance and land use intensity. The results showed that: 1) There was a two-stage change in the carbon emission performance in both space and time. The average value of carbon emission performance gradually increased from 0.63 to 0.77 from 2003 to 2013. Specifically, the high-value regions were concentrated in the coastal areas of Zhejiang and Jiangsu Province, whereas, the low-value regions were scattered in Huai'an, Lianyungang, and Huainan Province. By contrast, the average value of the carbon emission performance decreased slightly to 0.68 from 2013 to 2018, where there was a decreasing number of cities in the high-value regions. It infers that the regional energy saving and emission reduction fell into a short-lived bottleneck. 2) The average value of the regional land use intensity gradually increased from 349.74 to 356.63, with a clustered distribution pattern of the higher value in the north than in the south part of space. The low-value areas were mainly concentrated in some cities of Zhejiang Province in the south of the study area, while the high ones were located in the north, represented by Xuzhou in Jiangsu, Huaibei and Haozhou in Anhui Province. 3) A fluctuating upward trend was found in the coordination degree between carbon emission performance and land use intensity from 2003 to 2018. Among them, the low-value regions were mainly distributed in some cities of Zhejiang and Anhui Province in the southwestern part of the study area, whereas, the high ones were concentrated in Shanghai and coastal cities in Jiangsu Province, such as Yancheng and Nantong. There were also a higher average annual growth rate and an ever-increasing proportion of cities in the coordinating development, even in the transitional stage from 2003 to 2007. A plateau period was observed during low-carbon adjustment in the regional land use, particularly in the coordinating development stage from 2008 to 2018, but the growth rate gradually slowed down. In conclusion, the coordinating development between land use intensity and carbon emission performance can be expected as the land use planning for the low-carbon urban development in each city.