Projecting spatial interactions between global population and land use changes in the 21st century

Previous research on global urban land expansion has primarily focused on accommodating the growing population without adequately considering the trade-offs between urban land and ecological services. Consequently, it is important to investigate the effect of this expansion on the ecological service system, while also examining the potential trade-offs between population growth and available urban land. Here, we quantify how different global land expansion options contribute to reconciling global population changes and to compliance with the UN Sustainable Development Goal 11 on sustainable cities and human settlements. Using an integrated framework for projecting global land consumption with the trade-off strategy between global land expansion and population under shared socioeconomic pathways (SSPs), we aim to bridge the knowledge gap in this area. The results of our study suggest that implementing a trade-off strategy between global land expansion and population growth can successfully reduce the levels of global land consumption in the future. Under the SSP1 scenario, for instance, our findings indicate that implementing trade-off policies can significantly reduce land consumption while increasing carbon sinks and protecting the global ecological service system. Specifically, converting land to forest or grassland can help decrease land consumption by 8.07% by the end of the 21st century. These insights can be valuable in designing land use policies that incorporate data-based solutions and address the challenges of sustainable urban development while also accommodating population growth.