Urbanization may hurt environment

A study recently published in the journal Proceedings of the National Academy of Sciences suggests that urbanization will proceed rapidly within the next twenty years, which may threaten natural life.

The study, co-written by Karen Seto of the Yale School of Forestry & Environmental Studies, predicts that urban land cover by 2030 will be triple that of 2000 levels, and that most of this urban expansion will occur in developing nations. Researchers used projections of population and economic growth to come to their conclusions, which call attention to the need for environmentally conscious urban planning. One important impact of the projected urban land growth is a decrease in biodiversity due to loss of habitat, the study shows.

Brown University sociology professor Michael White said researchers in the field are aware that urbanization is an ongoing process, so the results of Seto’s study are not surprising. White added, though, that this particular study is notable because it draws a link between anticipated urban expansion and its impact on natural habitats and biodiversity.

Texas A&M University professor Burak Güneralp, a co-author of this study, said urbanization leads to a loss in vegetation, adding that it disrupts areas like tropical forests that store carbon. Without these carbon pools, the potential of the area to store carbon is diminished, he said. As a result, this carbon is released into the atmosphere instead — which could have a lasting impact on climate change — Güneralp said.

To determine projections on growth and distribution of urban land cover, researchers used forecasts of population and gross domestic product from the United Nations and the Intergovernmental Panel on Climate Change, respectively, Güneralp said. The study predicts that most of this anticipated urbanization will occur in developing nations. Africa is expected to see the highest rate of increase in urbanized land. The paper’s authors said they foresee urban growth in China and India contributing to 55 percent of Asia’s urban development.

Güneralp said developing nations may face greater challenges dealing with impacts of urbanization because they have access to fewer financial and institutional resources. He said support for the developing worlds could help curb the potentially detrimental impacts of urban development.

“Biodiversity itself may be most concentrated in developing countries, but we don’t really know what the economic value of the biodiversity is,” Güneralp said.

Despite its potential environmental effects, White said urbanization is not altogether bad or good. This study predicts how much urban areas will grow in the next couple of decades, but Seto said the way in which these regions develop will ultimately determine urbanization’s impact on the environment.

“I would caution you to think about what kinds of urbanization we want to look for,” White said. “There are different kinds of cities and different ways of living in urban areas.”

Seto said that over time, policy makers will focus on determining what they can do to shape how cities will develop, and how different forms of urbanization impact human experience and well-being. One way this might be done is to plan for the effect of loss of carbon pools, and to design means of storing carbon in urban environments, Güneralp said.

Lucy Hutyra of Boston University’s Department of Geography and Environment also co-authored the study.

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