Food waste and the climate crisis

Introduction

The global climate crisis is accelerating and nowhere are the effects felt more acutely than at the local level. The resulting impacts are causing immediate and long-term damages to our society, public health, safety, and overall quality of life. In light of these realities, communities are adopting plans to quickly achieve carbon neutrality (e.g., a2zero.org). These plans are ambitious, but they are well aligned with emerging dynamic and social norms.

These plan usually include a focus on reducing food waste. In the United States, food waste is estimated at 31 percent of the US food supply at the retail and household levels. Wasted food isn’t just a social and humanitarian concern,  it is also an environmental one. When we waste food, we also (1) waste all the energy, water, and resources it takes to grow, harvest, transport, and prepare it, and (2) contribute the related greenhouse gas emissions. For instance:

• If food goes to the landfill and decomposes, it produces methane, a greenhouse gas that is over 85 times more powerful than carbon dioxide. About 11 percent of all the greenhouse gas emissions that come from the entire field-to-table food provisioning system could be reduced if we eliminate food waste.
• Household food behavior has serious implications for energy usage. A study by the consulting group McKinsey found that, on average, household food losses are responsible for eight times the energy waste of farm-level food losses.

Defining food waste

USDA’s Economic Research Service (ERS) defines food waste as the edible amount of food, post-harvest, that is available for human consumption but is not consumed for any reason. The USDA uses the general term “food loss and waste” to describe reductions in edible food mass anywhere along the field-to-table food chain.

Causes of food waste

Food waste occurs for many reasons, with some types of loss, such as food spoilage, occurring at every stage of the food provisioning system: 

• Between the farm gate and retail store, food waste can arise from problems during drying, milling, transporting, or processing that expose food to damage by insects, rodents, birds, molds, and bacteria. Food waste results as well as from equipment malfunction (such as faulty cold storage), over-ordering, and removal of blemished produce. 
• Households also contribute to food waste when buying or cooking more than needed, not using bruised fruits and vegetables, using “best-before” dates as instructions to throw out, and choosing to discard any leftovers. Each week, a mountain of food slips through our fingers and into the trash.

U.S. goal to reduce food waste

In 2015, the USDA joined with the U.S. Environmental Protection Agency (EPA) to set a goal to cut our nation’s food waste by 50 percent by the year 2030.

Ways to reduce food waste

The best approach to reducing food loss and waste is not to create it in the first place. Waste can be prevented by improving food storage, shopping, ordering, marketing, labeling, and cooking methods. If excess food is unavoidable, households can donate excess to food recovery organizations so that they can feed people in need. Inedible food can be recycled into other products such as animal feed, compost, and worm castings, and bioenergy. The USDA and EPA created the food recovery hierarchy to show the most effective ways to address food waste (see Figure 1). 

Figure 1 – Food Recovery Hierarchy (EPA 2021)

Household behavior change

Although not all levels of the EPA hierarchy are available to households, the most preferred—source reduction—starts at the household, and has positive food saving impacts throughout the entire food provisioning system. Major contributors to household food loss and waste—and therefore areas ripe for behavior change—include (FoodPrint 2021):

1. Food spoilage — Over two-thirds of food waste in the household is from food not being used before it spoils. Spoilage occurs due to improper storage, lack of visibility in cabinets, freezers, and refrigerators, partially used supplies, and mistakes estimating food needs.
2. Over-preparing — The remaining third of household food waste is the result of serving too much food. Food portions have increased dramatically over time, and meals often include more food than can be eaten at one sitting. The Cornell Food and Brand lab found that since 2006, serving sizes in the classic cookbook The Joy of Cooking have increased by over a third. In addition, we forget to eat leftovers, and end up throwing them away.
3. Overbuying — Sales on novel products and sales promotions that encourage impulse and bulk food purchases at stores can lead households to buy items that do not fit their normal food preferences and, therefore, spoil before they can be used.
4. Date label confusion — About 80 percent of Americans unnecessarily discard food due to confusion over the meaning of date labels (e.g., sell by, best if used by, expires on). In fact, the “sell by” and “use by” dates are not federally regulated and only serve as suggestions for peak flavor and quality.
5. Poor planning — Without a previously created meal plan and shopping list, households can make inaccurate estimates of what and how many ingredients they will need during the week. Unanticipated restaurant meals or food delivery also can lead to food at home spoiling before it can be used.

References

EPA (2021) Food recovery hierarchy. Retrieved from: https://www.epa.gov/sustainable-management-food/food-recovery-hierarchy

FoodPrint (2021) The problem of food waste. Retrieved from: https://foodprint.org/issues/the-problem-of-food-waste

Raymond De Young
School for Environment and Sustainability
University of Michigan, Ann Arbor, MI 48109

Updated: March 16, 2021

Copyright © 2021 Raymond De Young, All Rights Reserved.