(MintPress) – A new study detailing the need of human beings to further reach into undeveloped areas as the population grows says that city populations across the world are expected to grow by 5 billion people by 2030. Because of the upward trend, more land will need to be consumed – more than 745,600 square miles, according to the study published in the Proceedings of the National Academy of Sciences. The report is a projection of urban sprawl, the term coined for urbanization that impacts vegetation, carbon dioxide output and native species of animals.
While urban sprawl is a multi-faceted issue, the Almanac of Policy Issues characterizes it as “low density, automobile dependent development beyond the edge of service and employment areas.” Homes and developments on the outskirts and beyond suburbs are the most common examples of urban sprawl in America, particularly the dependency on automobiles as a form of transportation.
On a global scale, projected growth can be devastating for ecosystems and biodiversity. The study classifies around three dozen biodiversity “hotspots” around the globe – or places that are native to animals not found anywhere else on the planet. Researchers estimated that the population trends would likely result in the urbanization of 3 percent of those hotspots, with more being indirectly affected by carbon emissions that result from paving over marshes, forests and grasslands.
To accommodate for the 5 billion more people estimate to populate the Earth by 2030, researches said that around 1.38 billion tons of carbon emissions would be required to build the necessary infrastructure and homes.
As it pertains to animals, the Alliance for Zero Extinction (AZE) says that 214 of the species that the group considers endangered or critically endangered would be impacted by the projected expansions.
“Africa and Europe are expected to have the highest percentages of AZE species to be affected by urban expansion, 30 percent and 33 percent, respectively,” the study’s authors wrote. “However, the Americas will have the largest number of species affected by urban expansion, 134, representing one-quarter of all AZE species in the region.”
Impacts of sprawl
The Clean Water Action Council (CWAC) has studied the land effects of sprawl for decades. The organization says the drastic decrease in arable farmland is one of the most detrimental effects of sprawl seen in the United States. Between 1950 and 2002, the number of acres of farmland in Wisconsin has decreased by 32.6 percent, the group noted.
Nationwide, more than 13.7 million acres of farmland was converted to non-farm use between 1992 and 1997. Its correlation to population growth becomes more evident, as the previous figure is 51 percent higher than the time between 1982 and 1992.
“We’re chewing up farms at an alarming rate across the U.S., to create new highways, fringe industrial parks and sprawled housing developments. This loss reduces our ability to grow food, fiber and timber. In many areas, urban development pressure and increased property taxes are forcing farmers out of business. They often sell their farms for housing developments, to provide financial security for their retirement.”
Other studies suggest that sprawl may be bad for the very people causing it. In 2003, the American Journal of Public Health and the American Journal of Health Promotion argued that obesity rates in America have gone up as urban sprawl has become more of a trend because nothing is within walking distance for those who rely on commuting.
Sprawl has resulted in twice as many miles traveled by Americans since 1963 – and they’re not going by foot. And a study published in the American Journal of Health Promotion found that people in more sprawling suburban areas weigh as much as six pounds more on average than those in more densely populated cities.
In a study to demonstrate how automobiles become an exclusive form of transportation for those on the fringe and beyond suburbs, departments at the University of Virginia compared the driving habits of teenagers in sprawled areas to those in suburbs and populated cities. The report noted that teens in sprawling counties were twice as likely to drive more than 20 miles per day compared to teens in compact counties.
National Household Transportation Survey (NHTS) cites that trend as a risk because teens are far more likely to be involved in auto accidents involving a fatality than adults when compared to per-mile rates.
“Given the stark relationship between driving exposure and fatality risk among teens, increased efforts to understand and modify the effects of sprawl on adolescent driving behavior are necessary,” the study concluded.
The effects of sprawl have been long documented, as the Center of Disease Control and Prevention (CDC) cites increased water pollution (urban runoff), air pollution and energy consumption as public health threats that it attributes to urban sprawl.
“As we address sprawl on a variety of levels, from personal transportation decisions to local zoning ordinances, from regional mass transit and land use decisions to federal regulations, it is essential to incorporate health considerations into policy making,” the CDC argued in a study of sprawl and health effects. “Because the health effects of sprawl are unevenly distributed across the population, it is equally essential to incorporate considerations of social justice and equity.”
Influence of a recession
While urban sprawl showed remarkable upward trends over the span of decades, there is information suggesting that the role of the recession and collapse of the housing market may be playing a role in the halt of sprawl. Census estimates and a USA Today analysis show that developments on the fringe of suburbs have had trouble filling empty homes and that population growth in fringe counties has halted from year-to-year comparisons.
The analysis showed that central metro counties accounted for 94 percent of U.S. growth after the recession set in during 2008, compared to 85 percent in the years prior to the recession. Experts cite aging Baby Boomers and Millennials – two of the most populous demographics – as preferring to live in urban areas rather than fringe properties.
John McIlwain, senior fellow for housing at the Urban Land Institute, said the stagnant recession will likely quash most efforts to sprawl because the infrastructure is expensive for cities and most are less likely to risk a failed housing development at this point in the economic downturn.
“I’m not sure we’re going to see outward sprawl even if the urge to sprawl continues,” McIlwain said. “Counties are getting to the point that they don’t have the money to maintain the roads, water, sewer. … This is a century of urbanization.”