Meta-analysis to provide first estimate of how fast urban areas grow

Researchers from IHDP’s core project UGEC just co-published a meta-analysis in the scientific journal PLoS ONE, revealing the risks that the explosive growth of cities poses to people and the environment.

The paper predicts that by 2030 urban areas will expand by 590,000 square miles to accommodate the needs of 1.47 billion more people living in urban areas. According to Karen Seto, the study’s lead author and UGEC co-chair, these cities will likely be developing and expanding into most biologically diverse, sensitive areas, such as forests, savannas and coastlines – the latter being the most vulnerable, exposing people and infrastructure to environmental disasters such as flooding or tsunamis.

The meta-analysis provides the first estimates of how fast global urban areas are currently growing, and how that growth may develop in the future. It is drawn from peer-reviewed studies that used satellite data to map urban expansion, and found that from 1970 to 2000 the world's urban footprint had grown by at least 22,400 square miles.

The authors also discovered that fewer than half of the world’s largest 100 urban areas have been studied in-depth, with findings published in peer reviewed journals. Furthermore, the analysis found that coastal cities have higher rates of urban land expansion than non-coastal urban areas. The projected four-fold increase in global urban extent by 2030, with urban extent growth rates surpassing the rate of urban population growth consistently across regions for the next two decades, poses significant global environment risks. image

Click here to view the full paper, “A Meta-analysis of Global Urban Expansion”.