Spatiotemporal differences of population spatial equilibrium in urban agglomeration and its carbon emission reduction effect: A case study in China

Seeking a scientific and reasonable population structure is the key to realizing low-carbon and green development of urban agglomerations. Based on the coupled coordination degree model and exploratory spatial data analysis (ESDA), this paper studied the spatiotemporal differences of population spatial equilibrium in Changsha-Zhuzhou-Xiangtan urban agglomeration, and constructed a nonlinear dynamic panel econometric model and quantile regression model to empirically test the carbon emission reduction effect and its heterogeneity of the population spatial equilibrium. The research conclusions are as follows: First, the population spatial equilibrium index of Changsha-Zhuzhou-Xiangtan urban agglomeration shows an upward trend in time, but the overall level is not high and the internal gap is obvious. In space, it presents a situation of concentration in the central urban area of Changsha. Second, the carbon emissions of Changsha-Zhuzhou-Xiangtan urban agglomeration have obvious dynamic inertia and path-dependent characteristics. That is, the carbon emissions of the previous period will significantly promote the carbon emissions of the current period. Third, the carbon emission reduction effect of population spatial equilibrium has the characteristics of an inverted “U” shape, and the population spatial equilibrium index in most areas is too low to achieve carbon emission reduction. Fourth, the legal environment helps to promote the spatial balance of population, thereby reducing the regional total carbon emissions, per capita carbon emissions and carbon emissions per unit area. Last, Changsha-Zhuzhou-Xiangtan urban agglomeration needs to improve the level of economic development and government expenditure to realize the carbon emission reduction effect. In general, Changsha-Zhuzhou-Xiangtan urban agglomeration should take into account the development of economy and environment in the process of improving the level of population space balance, so as to achieve a win-win situation for economy and environment.