Researchers from Yale, Texas A&M and Boston University say, in a new study, that urban areas will expand by 463,000 square miles if current population density trends remain constant. As cities spend trillions of dollars over the next two decades building new roads, buildings, and other infrastructure, the equivalent of 20,000 American football fields will be converted to urban land every day.
While living in urban areas can be a more efficient way to live, the researchers say that global urban development will have to get smarter in order to reap those benefits. If not, it could mean a major blow to biodiversity and carbon emissions.
“Urbanization is often considered a local issue, however our analysis shows that the direct impacts of future urban expansion on global biodiversity hotspots and carbon pools are significant,” said Karen Seto, the lead author of the study and an associate professor at Yale. "The world will experience an unprecedented era of urban expansion and city-building over the next few decades. The associated environmental and social challenges will be enormous, but so are the opportunities."
The study suggests that cities building new infrastructure should consider infrastructure projects that "avoid infrastructure 'lock-in,' be adaptable to unforeseen demands, and have low embodied and operating energy needs."
If not, the largest urban land expansion in "all of history" will negatively impact the habitat for hundreds of animal species already on critically endangered or endangered lists and increase carbon emissions through deforestation.
Most of the growth, about half, is expected to happen in Asia, mostly from China and India. Africa will see the fastest urban growth with a 590 percent increase from its urban land mass in 2000. In North America urban land area will double.
Read the study here.
Photo: Flickr/Image Zen