Population density regulation may mitigate the imbalance between anthropogenic carbon emissions and vegetation carbon sequestration

Abstract

The growing imbalance between anthropogenic carbon emissions and vegetation carbon sequestration is impeding cities’ sustainability. However, previous research has not reached a consensus on whether population density regulation can mitigate this growing imbalance. In this study, we first used the carbon footprint pressure (CFP) indicator to examine the temporal and spatial characteristics of the imbalance in 370 Chinese cities over the last 20 years. Second, we demonstrated the favorable but limited effect of existing technology on CFP mitigation using the IPAT equation, the Logarithmic Mean Divisia Index decomposition approach, and the Kaya identity. Further, we emphasized the dominant effect of the population on CFP in urban agglomerations and provincial capital cities through Maxwell's triangle. Finally, using a built panel data model, we identified an inverted U-curve relationship between CFP and population density at the middle and low quartiles, whereas population clustering promoted CFP mitigation at the upper quartiles. Given the limited effectiveness of current climate actions, as well as the coexistence of urban diseases and unoccupied buildings, we provided differentiated policy implications in city-scale for population density regulation. This study provides some inspiration for authorities to formulate city-scale population policies to mitigate climate change and achieve sustainable development.