Most Americans could be fed entirely by food grown or raised within 100 miles of their homes, according to a new UC Merced study published Monday.
The two-year study, led by environmental engineering professor Elliott Campbell, maps the potential of every American city to obtain food locally.
Using data from a farmland-mapping project funded by the National Science Foundation and information from the U.S. Department of Agriculture, Campbell also found that most areas of the country could feed between 80 and 100 percent of their population with food grown or raised within 50 miles, the university announced.
The study, “The Large Potential of Local Croplands to Meet Food Demand in the United States,” was published Monday in the newest edition of the science journal Frontiers in Ecology and the Environment.
Campbell and UC Merced graduate student Andrew Zumkehr took a look at farms near every major population center in the country. By comparing the potential calorie production to the city’s population, researchers found the percentage of the population that could be supported by locally grown food.
Campbell said the idea of the “farm to table” idea is growing by leaps. People have become more interested in supporting local farmers and getting fresher foods, he said.
“It’s still a niche market, but it has taken off quickly,” Campbell said. “It’s no longer just farmers markets, but restaurants and even stores like Walmart are getting into the mix.”
Through the research, the group found that despite limited resources and growing populations, many major coastal cities still have the potential to sustain their populations.
New York City, for example, could feed only 5 percent of its population within 50 miles, but as much as 30 percent within 100 miles.
The Los Angeles area could feed as much as 50 percent within 100 miles. Local agricultural areas, including Merced, Fresno and Sacramento, still have the farmland to feed 100 percent of their population, Campbell said.
The conversion of agricultural land to residential and commercial land has a significant impact on a city’s potential to feed its residents, Campbell said. The researchers found that Atlanta has lost so much surrounding farmland that it could only support a very small percentage of its people.
The study’s findings, the professor explained, allow for longtime development of land preservation so that food production stays intact. Policies and careful planning are needed to protect farmland suburbanization and to encourage local farming, the professor said.
Researchers also found that diet can make a difference in the results. For example, local food around San Diego can support 35 percent of the people based on the U.S. diet. This jumps to 51 percent of the population if people switched to plant-based diets, the study showed.
UC Berkeley professor and author Michael Pollan said Campbell’s research is contributing to the discussion of local food systems.
“That conversation has been hobbled by too much wishful thinking and not enough hard data – exactly what Campbell is bringing to the table,” Pollan said in a news release.
Researchers also said that a big part of food sustainability is recycling nutrients, water and energy. Zumkehr, the graduate student who contributed to the research, explained that when cities produce waste material, a lot of it ends up in landfills, but local waste can be repurposed as compost.
Zumkehr said he and Campbell looked at data from 1850 to 2000. Zumkehr does not expect much change between 2000 to 2015. “We’re thinking not much has changed because agricultural areas have stabilized, meaning we’re not losing or gaining farmland,” he said. “We also don’t have trends of large migration.”