Energy Impacts of Food Waste in the United States

Valarie Allman
January 29, 2018

Submitted as coursework for PH240, Stanford University, Fall 2017


Fig. 1: African Woman selling produce at market, showcasing supply chain process in low- income communities. (Source: Wikimedia Commons) RBL

It is estimated in 2020 that the worlds population is going to be 7.62 billion people. This means the population will increase by an estimated 54 million people in the next two years. [1] With there being an increasing pressure on already limited natural resources, we are living in a time where it is essential to understand the landscape of food waste in the world. With an estimated 1 billion individuals currently malnourished globally, how is it possible that one third of produced food (based on weight) that still has utility is lost within the food supply chain? [2,3]

Global Food Waste

While food waste differs in every continent, collectively it accumulates to one of the worlds largest issues. Research has indicated waste trends vary most directly based on income level per country. In low-income economies such as Sub-Saharan Africa, Western Asia, and Latin America food loss is at a high early in the supply chain (See Fig. 1). Due to poor infrastructure, transportation, refrigeration, inadequate market conditions, and below standard packaging, large quantities of food are lost early in their lifecycle. [3] These losses occur in the supply chain (SC) and ultimately don't have the chance to fall in the hands of their end consumer. These consumers barely ever produce waste as food is a scarce resource to start. However, these regions have heavily invested and innovated in creative ways to preserve food products in the SC as they year over year have dramatically decreased their food waste. [3]

This starkly differs with high income economies like the United States, Canada, and Europe who continue to have a steady increase in food waste year over year. Most waste accumulates late in the food supply chain. With higher standards in food, waste grows as a product of quality standards (aesthetic defects, blemishes, broken), manufacturer processes (scraps, over-stocking), poor conditions during display (temperature management in stores), and best-before-dates (consumers not consuming by date, consumers uneducated about time-sensitive products). [3]

Economic and Environmental Impact

What does 1/3rd of global food waste really mean in terms of our economy and environment? The Food and Agriculture Organization of the United Nations (FAO) estimates that of all edible food produced for human consumption about 1.3 billion metric tons is wasted. In the United States, between agriculture, consumer, and supply chain waste this comes out to a total of $165.6 billion dollars. With the top three groups being meat (41%), vegetables (17%), and dairy products (14%), this $1.3 billion equates to 1.12% of the total GDP. [4]

In terms of our environment, Kummu et al. estimate that an additional 1.9 billion individuals could be fed if the lost food supply could be saved. [3] Precious natural resources are invested into empty returns with the most abused resource being freshwater. The agriculture industry uses 70% of the world's freshwater supply. Based on of produced food being wasted, 17.5% of freshwater resources end up being wasted on unconsumed food. [5] With approximately 35% of the global population is living under high water stress or shortage, this is a resource we do not have the luxury of wasting. [6]

An additional negative environmental impact is the release of global warming and water tampering gases. With rotting landfill comes substantial quantities of methane gas. A gas that is 25% more powerful than CO2: the emission would had been produced if the food would have reached its end state through digestion. [7] Additionally with 25% of unused fertilizer contributing to wasted food, chemicals like nitrogen and phosphorus are emitted into water thus compromising its quality.

Going forward while it is inevitable that a certain amount of food can't be consumed such as inedible meat produce, table scraps, post-date food, etc. it is important to think of how these "wastes" are used. Often times food waste has the opportunity to a second life outside of it's traditional ending of incineration for energy recovery, feed or composting. With there being new innovative methods to turn waste into high value products such as fragrances, pharmaceuticals, fuel, fibers, and antioxidants, the future of supply chains have to account for post production methods to make sure the needed foods to produce these goods are established. [6]


Food waste is a huge issue and the cause of the worlds largest 21st century epidemic: starvation and malnutrition. If we are able to make changes as community to minimize supply chain waste, maximize food distribution, and educate the collective on our eco-system we can make changes to positively impact our planet and stop contributing to global warming. We then open the door to be more sustainable as a planet and reallocate funds to meaningful operations.

© Valarie Allman. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] W. Lutz, W. P. Butz, and S. KC, eds. World Population and Human Capital in the Twenty-First Century (Oxford University Press, 2014).

[2] R. L. Naylor, "Expanding the Boundaries of Agricultural Development," Food Secur, 3, 233 (2011),

[3] M. Kummu, et al., "Lost Food, Wasted Resources: Global Food Supply Chain Losses and Their Impacts on Freshwater, Cropland, and Fertilizer Use," Sci. Total Environ. 438, 477 (2012).

[4] J. C. Buzby and J. Hyman, "Total and Per Capita Value of Food Loss in the United States," Food Policy 37, 561 (2012).

[5] M. Kummu et al., "Is Physical Water Scarcity a New Phenomenon? Global Assessment of Water Shortage Over the Last Two Millennia," Environ. Res. Lett. 5, 034006 (2010).

[6] C. S. K. Lin et al., "Food Waste as a Valuable Resource for the Production of Chemicals, Materials and Fuels. Current Situation and Global Perspective," Energy Environ. Sci. 6, 426 (2013).

[7] K. D. Hall et al., "The Progressive Increase of Food Waste in America and Its Environmental Impact," PLoS ONE 4, e7940 (2009).