Southeast on Track to Develop ‘Megalopolis’ from Raleigh to Atlanta

Urban areas in the southeastern United States will double in size by 2060 unless there are changes to land development, according to a study by the Department of Interior’s Southeast Climate Science Center and North Carolina State University.

The predicted growth would come at the expense of agricultural and forest lands, creating an urban “megalopolis” stretching from Raleigh to Atlanta, which also raises a number of ecological concerns, the scientists say.

“If we continue to develop urban areas in the Southeast the way we have for the past 60 years, we can expect natural areas will become increasingly fragmented,” said Adam Terando, a research ecologist with the U.S. Geological Survey, adjunct assistant professor at N.C. State, and lead author of the study. “We could be looking at a seamless corridor of urban development running from Raleigh to Atlanta, and possibly as far as Birmingham, within the next 50 years.”

Expected Impacts

To understand how urban and natural environments could change, the researchers used N.C. State’s High Performance Computing services to simulate urban development between now and 2060 across the Southeastern United States.

Among the expected impacts of such expansive urban growth, the fragmentation of natural areas would significantly limit the mobility of wildlife, making it more difficult for them to find mates, raise young, find food and respond to environmental changes.

“This, in turn, increases the likelihood that we’ll see more conflicts between people and wildlife, such as the increasing interactions with bears we’re seeing in our suburban areas,” Terando said.

An increase in urbanization would also make urban heat islands – the warming of cities due to human activities and development – more common, favoring species that can take advantage of the hotter conditions in cities. For example, previous studies have found that insect pests – such as scale insects – thrive in urban environments.

“Unless we change course, over the next 50 years urbanization will have a more pronounced ecological impact in many non-coastal areas of the Southeast than climate change, said Jennifer Costanza, a research associate at N.C. State and a co-author of the study.

“It’s impossible to predict precisely what the specific ecological outcomes would be, but so far, the projections are not good in terms of biodiversity and ecosystem health.”

Decision makers involved in community planning will need a well-thought out strategy for future development.

“Given that urbanization poses significant challenges to this region, decision makers will need to begin serious, long-term discussions about economic development, ecological impacts and the value of non-urban spaces,” Costanza said.

The paper, “The southern megalopolis: using the past to predict the future of urban sprawl in the Southeast U.S.,” is published in PLOS ONE. The paper was co-authored by Adam Terando, Alexa McKerrow and Jaime A. Collazo of USGS; and Jennifer Costanza, Curtis Belyea and Rob Dunn of N.C. State.

The work was supported by the DOI Southeast Climate Science Center based at N.C. State.