Alternative SSPs urbanization projections based on the Degree of Urbanization data

LEIWEN JIANG, Shanghai University and Population Council
Lewis Dijkstra, European Commission
Alessandra Carioli, European Commission

As a core component of new climate change scenarios, the SSPs urbanization projections have been widely used to guide long-term global strategies across climate, infrastructure, environmental protection, and social policies. However, the data used for the existing projections was from the UN WUP. It is based on national administrative definitions that vary across countries and change over time. To make the projections more spatially compatible and temporarily consistent, this paper uses a newly developed Degree of Urbanization (DOU) data to generate an alternative set of SSPs urbanization projections for the climate change research communities. Adopting an improved urbanization projection model, we project urbanization trends for all countries and regions till the end of the century. The projection results are more robust and reflect a larger range of uncertainties in urbanization trends, embodied in the DOU data compared to the WUP dataset. While it does not aim to replace projections based on national definitions, the output provides an alternative set of projections that are more useful for comparative analysis. Moreover, DOU data is geocoded. It can provide spatial data across geographical scales, and produce consistent urbanization projections for territories at global, continental, national, and subnational levels.

Keywords: Internal Migration and Urbanization, Population, Environment, and Climate Change, Population projections, forecasts, and estimations, Population and Development

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