So Much Wasted Energy – Rethinking food waste
May 20, 2013
This is the final part of our serialization of Chapter 4 (Energy) from the latest Resilience guide, “Rebuilding the Foodshed: How to Create Local, Sustainable & Secure Food Systems“. This installment shows the big problem we have with waste, but also suggests that this is an area where we can all wade in.
Like everything else in the food system, food waste isn’t that simple. Unlike everything else in the food system, waste knows no bounds—that is, it cuts across all components of the food system. Food is lost and wasted in every sector, from production to consumption. However, the pervasiveness of food waste also means that it’s one of the biggest opportunities for rebuilding local food systems. Before making that argument, though, it is important to understand the issue of food waste in more detail.
Technically speaking, the term “food loss” is related to losses of quantity and quality of food in the initial production, processing, and distribution stages. “Food waste,” in contrast, tends to refer to the loss of food in the later stages of the food chain, ranging from storage spoilage to kitchen prep scraps to unconsumed prepared foods. The distinction between these terms can be helpful, but for the sake of simplicity, most discussions opt to avoid misconstrued nuances and simply use “food waste” as an allencompassing term.27
Regardless of terminology, one point is writ clear: the most technologically and economically advanced cultures in the world have the highest rates of food waste on the planet—and that’s even without including the astonishing amount of packaging and carry-out containers associated with our dietary habits. You would think that nations endowed with such economic and technological capacities would lead the way in reducing and recapturing food waste, but we are far from that reality, as evidenced in figure 4-8.
Every time food is lost or wasted, all of the embedded energy that went into producing that food is also wasted. In other words, the dilemma is not just about the loss of the calories and the nutrients in the food itself. Nor is it solely about the squandered opportunity to feed the increasing number of malnourished people in our country and beyond, although that injustice alone should be reason enough to move us to act. Food lost and wasted is energy wasted. It also represents the arguably unnecessary dispersal of pesticides, carbon, airborne particulates, and other pollutants associated with producing foods.
Waste is generally the first element examined and redressed in an audit of any kind of energy system. It may not be the sexiest consideration, but it’s the most important: minimizing waste is the best way to maximize efficiency. Consider a home energy-efficiency analysis. Perhaps the homeowner is particularly excited about installing a renewable energy system (such as solar panels) for her home. The first step is not to size, site, or install the new system; rather, it’s to determine current wasted energy. Until the sources of wasted energy are addressed, it makes little sense to invest in new sources of energy, no matter how “clean” or “renewable” they might be.
Other than being much more complex than a home energy audit—by several orders of magnitude—a farm-to-plate energy audit also should focus on conservation. Only after we determine causes and potential remedies of food loss and waste can we then turn our attention to the energy systems employed in transforming seed and breed into the food on our plates. One strong but typically ignored argument for local food systems is that we can more easily track energy use and food waste in localized food systems than in the highly dispersed and complex food systems at the national and global levels. Furthermore, when we have to contend with waste on a local level, we tend to be more cognizant of the levels and the impacts of that waste. The more distant and dispersed the waste, the less heightened our awareness and concern.
Most of us are likely unaware of how much food is wasted on a global scale: Approximately one-third of the edible foods produced worldwide are never consumed by humans. That amounts to a stunning 1.3 billion tons of food wasted annually. In the United States, the food waste percentage is closer to 40 percent. In wealthier industrialized countries, food is lost and wasted throughout the entire food chain, but a significant amount of perfectly edible food is wasted at the end of the food chain. In poorer countries, food losses tend to occur more at the earlier parts of the food chain, with minimal waste closer to the consumer end.28
Food loss and food waste in the United States are so enormous in terms of squandered nutrients, dollars, and energy that the overall impact is hard to fathom, in part because the results are relatively well hidden in Dumpsters and landfills relatively far removed from our daily orbits. Somehow, we Americans each account for approximately 600 to 650 pounds of lost and wasted food, most of which we barely see or consider.29 And seldom do we connect food waste to energy waste.
Describing such food waste is an exercise in inexplicable contrasts. The immediate image is, of course, a reeking mishmash of spoiled foods compressed into an enormous metal container, oozing liquids that might even repel most vermin. But then there are utterly irrational images: Dumpsters full of perfectly intact packaged items still within their expiration dates, baked goods not even twenty-four hours old, five-star entrées that somehow never made it to the dining room. Or entire truckloads of fruit turned away from their destinations because they were too ripe and therefore had too short a shelf-life for a grocery store to accept. Regardless whether it came from the next town over or from Mexico, the entire shipment was bound for disposal. Composting has its merits, but human consumption should be the first priority. If that isn’t possible, livestock certainly relish such meals.
Many people, myself included, have long congratulated ourselves for feeding our livestock and compost piles with food waste, assuming that we have closed an important ecological loop. In reality, though, we’ve only put lipstick on a pig (I swear that pig winked at me when I did it myself, though), since the food that we compost or feed to our livestock typically has higher energy invested in its entire “life cycle” than the physical energy it delivers to our livestock. The positive aspect is that we are at least utilizing an efficient biological process to dispose of food waste, enhance soil fertility, and perhaps even sequester carbon.
This biological approach is generally more efficient than an approach utilizing mechanization and large-scale infrastructure, but it is not a silver bullet. By incorporating food waste into our livestock systems, we are in some ways progressing toward a less energy-intensive food system. But we also need to be honest with ourselves and acknowledge that we are doing more to address waste disposal than to reduce the energy footprint of wasted foods in any significant way. The energy losses occurred long before our livestock ever smelled a good meal coming.
It’s only natural for a pig or a chicken to be attracted to food waste, but should the same really be the case for a local food systems advocate? Absolutely. Not only can local communities audit their waste streams with more precision and care than a state or federal entity, but municipalities and regional agencies are already heavily involved in the management of solid waste streams. Advocates for local food systems shouldn’t waste any opportunity to further their cause, and with the proper framing of the arguments, unexpected allies will flock to the cause like . . . well, like seagulls to a landfill. Careful and creative management of food waste at the local level significantly energizes the rationale for rebuilding local food systems, as a result of these economic and environmental benefits:
- Maximizing the diversion and appropriate consumption of discarded or unused foods that are still edible, particularly for food insecure populations
- Maximizing the energy recapture of food waste through anaerobic digestion
- Minimizing the transport of heavy, water-laden food waste
- Minimizing nutrient loss from the food system by transforming food waste into engineered soils, while also reducing the potential for the leaching of these nutrients into waterways
- Highlighting local eating establishments that can document their efforts to achieve zero waste of food, eating utensils, and carryout containers
Keeping food waste local—whether in the form of charitable donations or compostable material—is both cost effective and energy efficient. Transporting, processing, distributing, and even storing food waste is energy intensive. Due to its significant water content and its bulk, food waste is heavy and expensive to transport. Landfills are essentially inefficient storage vessels that create unwanted by-products through decomposition and leaching. In fact, food waste comprises an astonishing one-third of all material sent to landfills, and it is estimated that landfills in the United States produce approximately 20 percent of the nation’s methane emissions—energy lost and pollution unleashed.30
In contrast to this absurd use of landfills, good management of compostable materials can reduce leaching, build soil fertility, and capture clean-burning methane. Urban agricultural initiatives are especially well suited to reap the multiple benefits of processing food waste, often in combination with other organic wastes such as leaves and grass clippings. Enormous amounts of food and other organic wastes are exported out of many urban areas on a daily basis, at significant cost to businesses and municipalities. At the same time, urban gardens, lawns, and parks need significant soil amendments not only to rebuild fertility in existing green areas but also to remediate potential garden and park sites constrained by concrete, asphalt, and compromised soils.
Some metropolitan areas, however, are working hard both to capture those valuable natural resources and to reduce costs. The West Coast has been leading the push for diverting organics from the waste stream, in part because of high tipping fees at landfills (“tipping fees” are the charges assessed for dumping different types of waste, normally on a per ton basis). Portland, Oregon, has been demonstrating just how quickly a city can move in capturing organics by instituting a weekly pickup of household food scraps and moving to a biweekly garbage pickup, thereby encouraging good separation practices at the household level and boosting regional compost production.31 In addition, Portland is set to activate the country’s first grid-tied municipal biogas generator, a facility powered by recovered food waste.32
Of particular interest to urban areas is the ability to convert these compostable materials into “engineered soils” that can be designed for the special needs of rooftop gardening and farming. These soils can be engineered to be light, highly absorptive, and crop-specific in their nutrients. Just as is the case on a rural farm or in a suburban garden, optimal soils in a green roof project yield optimal results—for crops and the buildings themselves. Green roofs quickly translate into urban acres, and they hold significant agricultural potential, while also moderating summer temperatures and capturing CO2. Keeping food waste local can significantly enhance the potential for local food security and accessibility, while also reducing the energy and climate impacts of food that is already energy-intensive.
In order to get a sense of just how much energy is contained in food waste, we need only compare it to human excreta (urine and feces, also known as biosolids). The energy from food waste has obviously not been “biologically processed” and utilized by our bodies. As a result, decomposition of an average ton of food generates approximately 376m3 of biogas (primarily methane), more than three times the biogas produced from the same quantity of biosolids in our wastewater systems.33
Communities and businesses across the globe are constructing anaerobic digesters, airtight vessels that are fed organic wastes such as food, biosolids, and yard waste. As these organic wastes decompose, methane is captured and utilized as fuel for heat, electricity generation, and even clean-burning vehicle fuel. In this way, keeping food waste local expands a community’s energy self-reliance, while also mitigating pollutants in waterways and the atmosphere and reducing disposal costs. Other countries around the world—industrialized and developing—are leading the way in adopting anaerobic digestion technologies, realizing savings and a sense of energy independence. In the meantime, the United States lags far behind—but leads the way in demonstrating how to waste a good opportunity and pay more to do it.
A final takeaway lesson with regard to energy, food systems, and waste stems from carryout containers and other food packaging. Our fast-paced food choices in the United States result in the disposal of approximately two hundred billion disposable cups per year. Yes, you read that correctly: two hundred billion. Starbucks alone sends coffee on its way out the door in three billion cups annually (and, to the company’s credit, it’s worked more diligently on the disposable carryout container issue than just about any grab-and-go company in the United States).34 To be fair, this says more about our consumption habits than about any one corporation. After all, the average American chooses to eat fast food about 150 times per year, and we collectively dispose of approximately 1.8 million tons of fast-food packaging every year.35
Maybe it’s worth going into a café, greeting other locals, sitting still for a few moments, sipping tea out of a real cup, tipping the waitstaff, and then waving good-bye, fully energized and steeped in local tradition.
27. For an overview of the terms “food loss” and “food waste,” see Jenny Gustavsson et al., Global Food Losses & Food Waste: Extent, Causes, & Prevention (Rome: Food and Agriculture Organization of the United Nations, 2011), http://www.fao.org/fileadmin/user_upload/ags/publications/GFL_web.pdf.
28. Ibid., 2.
296 | Rebuilding the Foodshed
29. Ibid., 5.
30. “Basic Information about Food Waste,” U.S. Environmental Protection Agency, accessed November 26, 2011, http://www.epa.gov/osw/conserve/materials/organics/food/fd-basic.htm.
31. William Yardley, “Cities Get So Close to Recycling Ideal, They Can Smell It,” New York Times, June 27, 2012, http://www.nytimes.com/2012/06/28/us/a-recycling-ideal-so-close-cities-can-smell-it.html?_r=1&pagewanted=all.
32. “First Municipal Food Waste-to-Renewable Energy Facility to Connect to Power Grid in Urban Setting in U.S.,” press release, August 23, 2012, http://www.prweb.com/releases/prweb2012/8/prweb9831566.htm.
33. Stephanie Pruegel, “Pioneering Partnership Optimizes Power Production,” BioCycle, July 2010, 51.
34. Anya Kamanetz, “The Starbucks Cup Dilemma,” Fast Company online, October 20, 2010, http://www.fastcompany.com/magazine/150/a-story-of-starbucks-and-the-limits-of-corporate-sustainability.html.
35. 2008 Fast Food Industry Packaging Report (Asheville, N.C.: Dogwood Alliance, n.d.), http://www.nofreerefills.org/download-report/.