The environmental impact of food waste

The world’s food supply chain eats up valuable natural resources and energy at every step of the process—from growing teeny soybeans to raising the chickens that eat those soybeans to transporting the eggs those chickens lay across the country. But unfortunately the stats on how much of that food goes to waste are sobering: One-third or more of what’s produced globally goes to waste. That means land and fossil fuels used to grow and transport our veggies, meats, dairy products, and snacks all go to waste as well.

Why is food waste an environmental problem?

Producing food takes a lot of resources—from the nutrients it sips from the soil to the packaging it requires to sit on grocery store shelves. Those steps and everything in between also require vast amounts of energy, often derived from fossil fuels, to power equipment like tractors on the farm and the vehicles that lug grub around the globe. That energy typically also means more emissions, and that all comes before we consider the harmful methane food waste produces as it rots in landfills around the world.

Here’s some of the many ways that food waste is contributing to some of the planet’s most pressing environmental challenges.

Greenhouse gas emissions and climate change

Food loss and waste accounts for a huge chunk of global greenhouse gas emissions: upwards of 10%, according to the United Nations.¹ That’s in part because food rotting in oxygen-poor landfills gets munched up by bacteria, which go on to release harmful methane. While landfills do have methods to trap these emissions—including wells that capture gas for treatment and reuse—the EPA estimates that 61% of the methane generated by food waste in landfills reaches the atmosphere anyway.²

It’s not just wasted food itself that causes excess greenhouse gasses. The food supply chain also emits nitrous oxide and carbon dioxide.^3,4 These gasses come from fertilizer use, soil management practices,⁵ and energy required throughout the supply chain, according to a 2021 report by the U.S. Environmental Protection Agency.⁶

How are fossil fuels used to make food?

All stages of food production require some sort of energy. On the farm, tractors use fuel, and it takes a decent amount of power to operate irrigation systems. Researchers found that irrigation consumed 60.6 terawatt-hours worth of energy across the country in 2018 (that represents less than 1% of America’s total energy and electric usage, but is still equivalent to the consumption of about 3.3 million homes).⁷ Food processing equipment and refrigeration systems (i.e. the supply chain) also require power. In fact, the food supply chain itself accounted for about 11% of the total annual energy use in America between 2004 and 2015, the EPA reports.⁸ 

Fertilizers also play a key role in food-related fossil fuel consumption, since producing the chemicals is an energy-intensive process. This is particularly true in the making of ammonia and nitric acid, which are basic components of fertilizers. A study published in 2020 in the journal Sustainability found that the global fertilizer industry represents about 2-3% of global energy demand.⁹ That’s not surprising given that worldwide fertilizer use has increased by 800% since the 1950s.¹⁰

Food processing and transportation

Transportation accounts for 6% of the total energy used throughout the food supply chain, according to the EPA.¹¹ About one-fifth of the food eaten in the U.S. is imported from places like Canada, the European Union, and Mexico, and about half of those imports are fruits and vegetables. High import rates, especially of fresh produce, is in part due to consumers’ demands for things like avocados and melons year-round. 

Food loss and waste accounts for a huge chunk of global greenhouse gas emissions: upwards of 10%, according to the United Nations.

One study published in 2022 found that global food transport accounts for about 19% percent of the food system’s total emissions (or 3 gigatons of carbon dioxide equivalent).¹² The environmental footprint of individual imports varies based on what the food item is, how far it must travel, and by what mode of transit. 

The final steps for food products—processing and packaging—are also heavily energy-dependent. These steps account for roughly one-quarter of the farm-to-table food system’s energy use, according to a 2020 study.¹³ Retail accounts for another 25%.

Waste of natural resources

One recent EPA study found that more than half of the vegetables grown on American farms were lost before they were even harvested.¹⁴ Common reasons for such oversupply include aesthetics or contracts between buyers and growers that have unrealistic quality requirements. In the United States alone, about 140 million acres of farmland are dedicated to food that will ultimately go to waste, according to the EPA. That area’s equal to the size of California and New York combined.¹⁵

In many cases, those farm fields were once natural systems like forests or meadows that were converted in order to grow food. The good news, though, is that that type of land use change has largely stabilized in the U.S. over the last 50 years, according to the U.S. Department of Agriculture. 

In addition to land, growing all those unused crops also wastes a lot of water—about 5.9 trillion gallons annually in the U.S. alone, according to the EPA. The federal agency estimates about 22 trillion liters of water (the same as the annual water use of more than 50 million American homes) are used on lost and wasted food throughout the entire supply chain in America every year.¹⁶ 

Agricultural practices and environmental degradation

Lost and wasted food still requires the same resources as the food that is used and eaten. That means about 778 million pounds of pesticides and about 14 billion pounds of fertilizer, according to the EPA.¹⁷ Runoff of chemicals and fertilizers can pose toxic threats to nearby bodies of water, where they can pollute marine ecosystems and fuel harmful algae blooms.

The way farmers tend their land can also have an impact. Many land use experts now recommend using cover crops instead of tilling soil in between plantings, which can actually help reduce runoff of nutrients like nitrogen.¹⁸ 

Impacts to biodiversity

Using land for food means it cannot be a natural habitat. Along with residential and commercial developments, farming can “fragment” ecosystems, reducing the contiguous spaces that wildlife can use. For example, the UK’s adorable dormouse is struggling because populations are cut off from one another.¹⁹ Eating up native habitats can also impact pollinators, soil health, and water filtration—while also releasing greenhouse gases.²⁰ The pesticides, herbicides, and fertilizers used on farmland can also pose serious threats to nearby aquatic ecosystems, causing toxic conditions that can lead to algae blooms and fish kills.²¹

A note about non-biodegradable PLU labels 

Those dime-sized PLU (price look up) stickers found on (almost) each and every fruit and vegetable purchased at the store add up, too. They help streamline many processes in the food supply chain, but they also pose an environmental problem because they are not biodegradable, according to the USDA. When those pesky stickers end up in commercial compost streams, they serve as contaminants that may then mean those fruits and veggies will wind up sent to the landfill, creating more food waste than intended. 

The impacts of specific food groups

No two food groups have the same impact when it comes to waste, but some are definitely worse than others. There’s no question that tossing animal-based products or other resource-intensive goods like cocoa or palm oil (both key drivers of deforestation in some parts of the world) can hurt our planet even more.

Meat and seafood

According to ReFED, a national nonprofit focused on food waste solutions, Americans wasted an estimated 5.08 million tons of fresh meat and seafood in 2022. One 2021 study on food waste found that while meat and fish only account for 10% of chucked grub, they’re the worst offenders in terms of environmental impact.²² That’s in part because those products spoil much faster than other foods, like processed cereals. It’s also due to the amount of energy required during processing and manufacturing. By one estimate, about 38% of the total weight of beef was wasted during the slaughtering and processing stages, making it the most wasted of the meats.²³

Dairy

Aside from meat products, dairy also has a large footprint when it comes to environmental impacts from food waste. Dairy production not only results in greenhouse gas emissions, but also causes nutrient runoff that can pollute local waterways.^24,25 According to ReFED, Americans wasted about 14.2 million tons of dairy and eggs in 2022. The USDA estimates that dairy products make up about 17% percent of all food waste that reaches American landfills and incinerators.

But there’s an easy solution here: Buying smaller containers of milk can significantly decrease a person’s dairy-based impact on the planet. In one 2021 study, single-person households that shifted from purchasing a half-gallon bottle of milk to a 1-quart container could reduce their greenhouse gas emissions by about 33% without a major change in consumption.²⁶

Grains (especially rice)

When it comes to the weight of lost and wasted food, at least in the United States, grains accounted for an outsized percentage at the farming level: 25.9 million metric tons, compared to 1.7 million metric tons of eggs lost at this same stage.²⁷ Grains are also one of the major food groups that are responsible for the majority of wasted food at later stages of production.

In the United States alone, about 140 million acres of farmland are dedicated to food that will ultimately go to waste, according to the EPA.

Rice, in particular, is a significant contributor of methane emissions in its worldwide cultivation. According to data from dozens of international researchers and organizations published in The Global Methane Budget 2000-2017, rice is responsible for an estimated 8% of total manmade methane global emissions.²⁸ That’s because most rice is grown in flooded paddy fields where oxygen levels are low—much like the anaerobic, albeit drier, conditions found in landfills. 

Differences in food waste by region

The U.S. isn’t alone in its food waste problem. Worldwide, crop production alone is responsible for upwards of 12% percent of human-created greenhouse gas emissions.²⁹ Current estimates say the food system as a whole is responsible for one-third of all human-caused greenhouse gas emissions.³⁰ Of that, about one-third of what’s grown is simply lost or thrown in the trash. Data published in the United Nations Environment Programme shows that households in China, India, Nigeria, Indonesia, and the United States waste the most food in the world.³¹

In America, researchers have found that higher income families and smaller households often produce more food waste, while other studies have noted that around the world, food waste happens at every income level.^32,33 As incomes rise and diets and populations diversify, some lower-income areas are actually seeing food waste rates also increase.³⁴

Preventing food waste for the planet’s sake

When we can figure out ways to have less food waste reaching the world’s landfills, we can also save—or in some cases repurpose—all of the other energy and resources already expended to create those foods. Or, better yet, there are solutions in the works to improve food production and supply systems in the first place.

Reducing waste during production

Preventing food waste before it hits the trash can is a key part in solving this global problem. ReFED lists several solutions for food producers that could save nearly 15 million tons of food from being wasted, totaling more than $2 billion in savings. Suggestions include finding new customers for crops that would otherwise be left unharvested and building better relationships with places that can distribute food donations.

Reducing waste at home

With so much waste happening at the household level, there are a lot of changes individuals can make to reduce household food waste, such as improved home inventorying to working on culinary and storage skills. People can also educate themselves on best-by dates, which can often lead to unnecessary waste.³⁵ Composting food also has its benefits. Home composting, if done correctly, offsets food from rotting in landfills and creating harmful methane due to the anaerobic (oxygen-poor) conditions.

Other strategies

Aside from donating food that would otherwise go to waste (which can be done at nearly every level, especially from farms, retail, and individual households), food waste can also be repurposed into animal feed and energy.

Food waste policies

Countries around the world have taken varied approaches to tackling food waste challenges. Pennsylvania State University professor Edward Jaenicke says the approach in South Korea, for example, has worked well. There, people are required to separate compostable waste, which is then weighed, and then a fee is generated based on the amount of waste. The New York Times reported that the country’s food waste policies, instituted nearly two decades ago, have kept about 90% of discarded food out of landfills and incinerators and have also set a precedent for other governments around the world.

There are a variety of official regulations or laws on the books in countries around the world, including China, Italy, Czech Republic, France, Germany, Norway, UK, Argentina, and Japan—not to mention the E.U. UN.³⁶ The United Nations, as well as U.S. agencies, has set a goal to reduce food waste by 50% by 2030. Stateside, federal agencies have awarded millions in grant funding to support recycling programs as well as efforts to curb food loss and waste in the first place. 

Some American states have also made strides in addressing food waste with local rules and regulations, such as New York City’s shift to extend sell-by dates of pasteurized milk products.³⁷ ReFED keeps an inventory of state-level food waste policies on its website.

How does reducing food waste help fight world hunger?

Food waste exacerbates a lack of access to food around the world. Healthy and good food is being trashed instead of being consumed. Waste also puts more pressure on existing resources and, ultimately, drives up supply, demand, and pricing, explains Ohio State University Professor Brian Roe. Food prices would go down by a “nontrivial amount,” he says, if food waste was tackled worldwide. If food waste was reduced by 10–20%, he says, that would mean less land and resources would be needed because less food would be needed—a win-win for people and the planet. 

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1. UNEP Food Waste Index Report 2021, United Nations Environment Programme, Mar. 2021 ↩︎
2. Quantifying Methane Emissions from Landfilled Food Waste, U.S. Environmental Protection Agency, Oct. 2023 ↩︎
3. Understanding Methane Emission from Stored Animal Manure: A Review to Guide Model Development, Journal of Environmental Quality, May 2021 ↩︎
4. The Global Methane Budget 2000–2017, Earth System Science Data, Jul. 2020 ↩︎
5. Effects of Land Use and Cultural Practices on Greenhouse Gas Fluxes in Soil, ACTA AGROPHYSICA, 2004 ↩︎
6. From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste, U.S. Environmental Protection Agency, Office of Research and Development, Nov. 2021 ↩︎
7. The Energy Footprint of U.S. Irrigation: A First Estimate from Open Data, Energy Nexus, Jun. 2022 ↩︎
8. From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste, U.S. Environmental Protection Agency, Office of Research and Development, Nov. 2021 ↩︎
9. Life Cycle Assessment of Nitrate and Compound Fertilizers Production—A Case Study, Sustainability, Dec. 2020 ↩︎
10. Implication of Imposing Fertilizer Limitations on Energy, Agriculture, and Land Systems, Journal of Environmental Management, Mar. 2022 ↩︎
11. From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste, U.S. Environmental Protection Agency, Office of Research and Development, Nov. 2021 ↩︎
12. Global Food-Miles Account for Nearly 20% of Total Food-Systems Emissions, Nature Food, Jun. 2022 ↩︎
13. Resource Requirements of Food Demand in the United States, U.S. Department of Agriculture, May 2020 ↩︎
14. From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste, U.S. Environmental Protection Agency, Office of Research and Development, Nov. 2021 ↩︎
15. Ibid ↩︎
16. Ibid ↩︎
17. Ibid ↩︎
18. Agronomic Assessment of Cover Cropping and Tillage Practices Across Environments, Agronomy Journal, Jun. 2020 ↩︎
19. Habitat Fragmentation and Its Lasting Impact on Earth’s Ecosystems, Science, Mar. 2015 ↩︎
20. Land Use Biodiversity Impacts Embodied in International Food Trade, Global Environmental Change, May 2016 ↩︎
21. Eutrophication: Early Warning Signals, Ecosystem-Level and Societal Responses, and Ways Forward, National Library of Medicine, Apr. 2021 ↩︎
22. The Extent of Food Waste Generation in the UK and Its Environmental Impacts, Sustainable Production and Consumption, Apr. 2021 ↩︎
23. Causes of Waste Across Multi-Tier Supply Networks: Cases in the UK Food Sector, International Journal of Production Economics, Jun. 2014 ↩︎
24. Research on Environmental, Economic, and Social Sustainability in Dairy Farming: A Systematic Mapping of Current Literature, Sustainability, Jul. 2020 ↩︎
25. Assessing and Reducing the Environmental Impact of Dairy Production Systems in the Northern US in a Changing Climate, Agricultural Systems, Aug. 2021 ↩︎
26. Modeling American Household Fluid Milk Consumption and Their Resulting Greenhouse Gas Emissions, Sustainability, Apr. 2019 ↩︎
27. A Framework to Quantify Mass Flow and Assess Food Loss and Waste in the US Food Supply Chain, Communications Earth & Environment, Apr. 2022 ↩︎
28. The Global Methane Budget 2000–2017, Earth System Science Data, Jul. 2020 ↩︎
29. The Influence of Crop and Chemical Fertilizer Combinations on Greenhouse Gas Emissions: A Partial Life-Cycle Assessment of Fertilizer Production and Use in China, Resources, Conservation and Recycling, May 2021 ↩︎
30. Invited Review: The Consumer and Dairy Food Waste: An Individual Plus Policy, Systems, and Environmental Perspective, Journal of Dairy Science, May 2022 ↩︎
31. UNEP Food Waste Index Report 2021, United Nations Environment Programme, Mar. 2021 ↩︎
32. Estimating Food Waste as Household Production Inefficiency, American Journal of Agricultural Economics, Jan. 2020 ↩︎
33. Global Food Waste Across the Income Spectrum: Implications for Food Prices, Production and Resource Use, Food Policy, Jan. 2021 ↩︎
34. Ibid ↩︎
35. The Effect of Sell-By Dates on Purchase Volume and Food Waste, Food Policy, Jan. 2021 ↩︎
36. The Status of the Global Food Waste Mitigation Policies: Experience and Inspiration for China, National Library of Medicine, Apr. 2023 ↩︎
37. The Effect of Sell-By Dates on Purchase Volume and Food Waste, Food Policy, Jan. 2021 ↩︎