Global projections of future urban land expansion under shared socioeconomic pathways

TLDR

Urban land, though covering a small area, has profound global environmental impacts. The study projects global urban land expansion scenarios under the shared socioeconomic pathways framework. The projections are generated at a 1‑km spatial resolution to preserve spatial detail. The projections show rapid urban expansion until the 2040s, with China and other Asian countries facing urban population decline after the 2050s, 50–63 % of new urban land on croplands, a 1–4 % decline in global crop production affecting 122–1389 million people, underscoring the need to govern urban land development to mitigate food production impacts.

Abstract

Abstract Despite its small land coverage, urban land and its expansion have exhibited profound impacts on global environments. Here, we present the scenario projections of global urban land expansion under the framework of the shared socioeconomic pathways (SSPs). Our projections feature a fine spatial resolution of 1 km to preserve spatial details. The projections reveal that although global urban land continues to expand rapidly before the 2040s, China and many other Asian countries are expected to encounter substantial pressure from urban population decline after the 2050s. Approximately 50–63% of the newly expanded urban land is expected to occur on current croplands. Global crop production will decline by approximately 1–4%, corresponding to the annual food needs for a certain crop of 122–1389 million people. These findings stress the importance of governing urban land development as a key measure to mitigate its negative impacts on food production.