Urban land-change futures: current understanding, challenges, and implications

Urban land-change forecasts can facilitate understanding causes and consequences of land changes due to urbanization. Yet, we do not know why these forecasts are generated, how reliable they are, and what they collectively tell us about future urbanization. Through a systematic review, we identified 601 papers reporting urban land-change forecasts: 518 papers for 322 case-study locations in 73 countries, 71 for large regions, and 12 for global analysis. In 44% of these, the motivation is simply forecasting future urban land. Accuracy and uncertainty assessments continue to be neglected. An ensemble of global forecasts suggests urban land may range from about 0.9(1) to over 2.5(5) million km2 by 2050(2100). Forecasts from the Global South are increasing but understanding of future urban land expansion remains uneven across city sizes and geographies. Progress on real-world relevance, reliability, and representativeness of urban land-change forecasts will greatly advance their potential to inform policies.