Spatial effects and influence mechanisms of urban land use green transition on urban carbon emissions

• Introduction of a pioneering analysis framework for the Urban Land Use Green Transition (ULUGT). • Exploration of the urban carbon reduction (UCE) effects stemming from ULUGT. • Identification of significant spatial spillover effects of ULUGT on UCE. • Emphasis on investigating the mediating mechanisms driving the impact of ULUGT on UCE. Reducing carbon emissions is essential for achieving the “dual carbon” targets. This study investigates the impact of Urban Land Use Green Transition (ULUGT) on Urban Carbon Emissions (UCE) and explores the underlying mediation mechanisms. Utilizing panel data from 107 cities in the Yangtze River Economic Belt (YREB) covering the period 2003–2021, we apply the Spatial Durbin Model and Mediation Effect Model to analyze the direct effects, spatial spillover effects, and mediation mechanisms of ULUGT on UCE. Our findings reveal that: (1) UCE in the YREB increased from 13.32 to 28.94 million tons, with an annual growth rate of 4.17 % between 2003 and 2021. Although UCE overall increased, significant spatial imbalances were observed, although these disparities have diminished over time. (2) ULUGT significantly reduces local UCE but generates positive spatial spillover effects on UCE in neighboring cities. (3) The impact of ULUGT on UCE varies according to resource endowment and geographic location. (4) Environmental regulations, industrial agglomeration, and green technological innovations act as mediation mechanisms, partially mediating the effect of ULUGT on UCE. This study highlights the need for enhanced regional cooperation, timely implementation of green technological innovations, and coordinated interventions to effectively mitigate UCE.