Assessing the Impact of Spatiotemporal Evolution of Urbanization on Carbon Storage in the Mega-Urban Agglomeration Area: Case Study of Yangtze River Delta Urban Agglomeration, China

A comprehensive understanding of the relationship between urbanization evolution and carbon storage is crucial for regional low-carbon development and the mitigation of global warming. In this study, we took a typical mega-urban agglomeration (Yangtze River Delta region) in China from 2000 to 2020 as an example, introduced an improved urbanization index to evaluate its urbanization level, and analyzed the impact of urbanization on carbon storage. The results show that in the past 20 years, the urbanization level of the Yangtze River Delta has increased by 3.25 times, during which, carbon storage has always shown a downward trend and decreased by 6.56 x 107 t. Furthermore, there was a gradually increasing negative correlation between urbanization and carbon storage. Lastly, the spatial loss of carbon storage is as follows: urban-rural fringes > rural area > developed urban area. From the perspective of stage characteristics, urban development periods that focus on outward expansion suffer faster losses. The results point out that we should focus on urban-rural fringes and control the urbanization development model in order to achieve carbon storage protection in rapidly urbanizing areas. This study provides a unique perspective on how to coordinate the relationship between regional urbanization and carbon storage services and achieve sustainability, especially for mega-urban agglomeration regions.