Waste Not
How Your Leftovers Can Destroy the World – or Save It

Food waste is probably the least sexy of all sustainability subjects. After all, it has to do with what we eat — after we’ve already eaten it. As long as we scarf down grass-fed beef, sustainable seafood and organic fruits and vegetables, we are good to go, right?

Unfortunately, it doesn’t work that way. The NRDC estimates that 40%, or over 30 million tons, of food in the United States is wasted, costing us a whopping $165 billion a year. The second largest category of municipal solid waste sent to landfills in the U.S., food waste accounts for approximately 18 percent of the total municipal waste stream, according to the Environmental Protection Agency (EPA). Of the less than 3 percent of food waste currently being diverted from landfills, most of it is being composted to produce fertilizer.

But fruits, vegetables, meats and grains — heck, the entire food pyramid — is naturally broken down by bacteria, right?

Well, yeah, but it’s not so simple. When bacteria break down organic material (your food), it produces methane, which packs 21 times the global warming punch of carbon dioxide. In other words, methane is no gas.

By putting food waste into landfills, we are not only contributing to climate change but also wasting a valuable resource. When properly processed, food scraps can generate clean, renewable energy, enhance the soil as a fertilizer and feed animals to boot.

According to the EPA:

“Composting food waste produces a natural fertilizer, which can create healthier soil and reduce the need for synthetic fertilizers. Through anaerobic digestion, bacteria can digest the food waste to produce methane, a valuable energy source when captured.”

Recognizing the opportunity to turn a problem into a profit, several governments in the United States and abroad are taking steps to close the loop on food waste. Last week, Massachusetts officials proposed a commercial food waste ban, along with $4 million in grants and low-interest loans to support facilities that can successfully convert such waste into renewable energy through anaerobic digestion. Sadly, residential food waste is not included in the proposed ban. But it's a start.

“Anaerobic digestion is yet another proven clean energy technology that supports the Patrick Administration’s energy goals,” said Mark Sylvia, Commissioner of the Massachusetts Department of Energy Resources. “By working together and leading by example, we are building the infrastructure to support clean, renewable energy generation and address a challenging organic waste issue with a solution that meets multiple economic and environmental goals.”

In the San Francisco Bay Area, the City of Petaluma has begun exploring ways to convert the wastewater generated by its industrial users into energy. Five months after several local food processors said they could no longer afford Petaluma's wastewater costs, the city is looking into ways to retrofit its sewer facility to accept high-density waste from industrial users and turn it into electricity that the city can use to offset energy costs. This is expected to result in a proposal to create a methane digester that turns waste into energy.

In May, The Kroger Company unveiled a clean energy production system to convert food that cannot be sold or donated into energy to help power its Compton, California, Ralphs/Food 4 Less distribution center. The Kroger Recovery System utilizes anaerobic digestion to convert more than 55,000 tons of organic food waste into renewable energy annually and provide power for the over 650,000 square foot distribution center.

Across the pond in London, the Westminster City Council has joined with Sturgis Carbon Profiling to apply for funding from the Government's Technology Strategy Board to explore the possibility of turning food waste from Soho restaurants into energy through anaerobic digestion. If the technology proves feasible and a way is found to limit negative side effects such as excess noise and odor, the Council says it will consider opportunities for implementation. This could include installing a compact underground generator in the heart of Soho.

“This could have multiple benefits for the council, including helping us to further increase our own waste management options, a reduction in waste transport movements, and contributing towards a reduction in fuel poverty and carbon emissions,” said Ed Argar, Westminster City Council cabinet member for city management.

Earlier in the year, UK grocer Waitrose achieved zero food waste to landfill in all 280 of its national branches through both anaerobic digestion and in-vessel composting.

To the north, Norway has so perfected the process of turning garbage into gold that it actually imports food waste, in addition to household trash, industrial waste and even toxic waste from hospitals and drug arrests. Nearly half of the Norwegian capital of Oslo and most of its schools are heated by burning garbage.

As cities around the world continue to face overflowing landfills and mounting climate concerns, more will look to methods such as anaerobic digestion to boost local economies and rejuvenate the environment. Reducing carbon dioxide will mean little in the long run if we do not also find a way to limit and eliminate methane.

According to the EPA, over 60 percent of methane emissions come from human activities.

But it wasn't me, I swear.