We Americans worry constantly about how our appetites affect our waistlines, but we spend almost no time wondering how our food consumption affects our waste streams. In the United States, 40 percent of the food grown each year is discarded uneaten. That’s a significantly higher amount of waste than the global average, which runs around one bite of food thrown away for every two bites eaten.
As a result, food waste is the single largest source of refuse heading for American landfills. Once buried in a landfill, discarded food decomposes anaerobically and creates methane, a greenhouse gas 21 times more potent than carbon dioxide.
And of course, growing all that food just to throw it out wastes water. According to the U.N.’s Food and Agriculture Organization, the U.S. wastes 50 cubic kilometers of irrigation water each year growing food that’s never eaten. That’s about one-fifth the total output of the Ohio River where it flows into the Mississippi. And growing that uneaten food also means wasted fossil fuel and pesticides: About 300 million barrels of oil globally go into growing, transporting, and preparing discarded food each year.
“Agriculture in the U.S. accounts for 80 percent of our water use, and it uses more than half of our land area,” said Dana Gunders, a staff scientist with the Natural Resources Defense Council. “If we ultimately aren’t eating 40 percent of the food we grow here, that’s a terrible use of our resources.
In the United States, around 35 percent of food is wasted by consumers: the diner who leaves a half plate of food, or the householder who lets leftovers go bad.
With most of that food going right to already bulging landfills, it’s no surprise that local governments are flocking to food waste collection and composting as an alternative. The number of communities offering at least some curbside food waste collection has grown like sprouts on a neglected potato, from just a handful in 2002 to more than 150 in 2012.
Most of those programs send their collected food scraps, often mixed with garden waste, to composting facilities. Some, like the Humboldt Waste Management Authority in Humboldt County, Calif., are working to build digesters that can turn food waste into fuel for transportation and power generation. Programs vary in size from tiny pilots serving a handful of residences to citywide mandatory programs, like the one San Francisco created in 2009.
But as a recent Wall Street Journal article pointed out, most cities don’t have the infrastructure to turn food waste into biofuel, and composting operations must contend with opposition from neighbors over potential smells. Besides, taking on food waste after it’s wasted doesn’t do anything to reduce the growing amount of resources that go into growing discarded food. The better path, say experts, is “source reduction,” or preventing the food from being wasted in the first place.
“Quite a few municipalities are interested in collection,” said Gunders. “They don’t all quite make the connection with source reduction. For instance, if food is being wasted due to spoilage, maybe it would be better to spend a few of the dollars being put into waste collection and spend it on coolers for food banks.”
“Composting gets a lot of the attention because it’s visible,” said Janet Haugan of LeanPath, a firm working to help commercial kitchens reduce the amount of food they waste. “Prevention is a lot less tangible.”
LeanPath offers kitchens gadgets that allow workers to weigh and catalog the food they throw out. That lets its clients reduce their food waste by up to 80 percent, often saving six percent or more on their total food costs.
“You can’t really understand how to reduce your waste unless you measure it,” said Haugan.
There’s another problem with all the perfectly good food we throw out: some of us could really use more to eat. Affluent countries waste 222 million tons of food a year, according to the FAO; if that food were more equitably distributed, it could help augment the 230 million tons that’s the total annual food harvest in Sub-Saharan Africa.
Hunger is a problem in those rich countries as well, affecting one in six Americans and one in four American children.
That fact isn’t lost on either NRDC or LeanPath. Along with groups such as the Northern California Recycling Association and a range of local recycling firms, they’re sponsoring the first-ever Zero Food Waste Forum in October in Berkeley, Calif.
Participants at the three-day forum will discuss common solutions to hunger and food waste. Experts and entrepreneurs will offer presentations on topics ranging from salvaging food from industrial kitchens to mobile phone apps that facilitate neighbors sharing their excess garden produce.
Gunders said the public response to the event has been startling, and she concludes that linking the two issues is an idea whose time has come. “We thought the Forum would be a very local Northern California event, but we’ve really been floored by the amount of interest nationwide.
“It seems there’s definitely a hunger for this kind of thinking,” Gunders added. “No pun intended.”