Towards sustainability: The impact of the multidimensional morphological evolution of urban land on carbon emissions

Abstract

The examination of explicit and implicit urban land forms and their impact on carbon emissions (CEs) can effectively balance economic development with environmental sustainability. Prior studies have only considered individual factors, such as the scale and structure of urban land use (ULU), without accounting for its multidimensional evolution. To address this limitation, we analyzed data from 44 cities around the Bohai Sea between 2000 and 2020, developing a land-use index system that includes urban land quality. Our results present a nuanced view of the urban land use patterns (ULUPs) in the Bohai Rim region over the 20-year period. We found that all indices of ULUPs demonstrated a trend of improvement. Specifically, the structural pattern index (TS) was typically high, with values ranging between 0.65 and 0.80. The quality pattern index (TQ) witnessed the most significant growth. In contrast, the scale pattern index (TA) and the layout pattern index (TP) registered a relatively lower and slower-paced growth. Simultaneously, we observed an intriguing pattern in the CEs in the Bohai Rim region - an initial surge was followed by a considerable slowdown, as the growth rate plummeted from 88% to a mere 3%. There were noticeable regional variances, with the Beijing-Tianjin-Hebei region registering a lesser increase compared to the Liaodong Peninsula. As our study progressed, we uncovered distinctive and evolving influences of the land use morphology factors on the Bohai Rim region's CEs. A progressively rising number of factors emerged as significantly influential, with their suppressive impact on CEs becoming increasingly potent. Notably, land allocated to public service facilities, green spaces, and squares was found to be associated with reduced CEs. Moreover, our study reveals a clear link between quality optimization of ULU and effective restraint on CEs, whereas larger scales of urban land result in increased CEs. Our findings also show that a continuous and stable optimization of the multidimensional pattern of urban land, accompanied by a relatively stable optimization path, can favorably suppress CEs. This confirms the critical role of strategic land use management in controlling CEs. Our paper provides policy guidance for creating low-carbon, sustainable cities through efficient leveraging of land resources.