The Social and Environmental Impacts of Food Waste

Students will explore the origins of food, describe how food waste affects natural resources and the environment, and identify potential solutions to mitigate food waste’s carbon footprint.

Grades: 9 – 12
Estimated Time: 2 hours
Updated: November 26, 2024
Tags: AP Environmental Science

Biology

Environment & Ecosystems

Sustainability

Background

Materials Needed

Engagement

Source Search relay materials:
- Colored index cards or cardstock in 2 different colors (for mounting product pictures)
- Four containers or baskets labeled “Stores,” Factories,” “Farms,” and “Natural Resources”
- Source Search Pictures, 1 copy*

* These items are included in the Source Search Kit, which is available for purchase from agclassroomstore.com

Activity 1: Food System Chains and Food Waste

Flowcharts, 1 per student (each student can receive the same flowchart, or you may pass out a variety of flowcharts)
- Livestock
- Berries
- Tree Fruits
- Grains
- Livestock
- Nuts
Exploring Origins: Where Our Food Comes From slide deck
- Save your own copy of the slide deck

Activity 2: Food Waste's Impacts on the Environment

Food Waste: The Hidden Cost of the Food We Throw Out
Harvard Foodprint Calculator and internet access for each student
Food Waste: Impact on the Environment slide deck
- Save your own copy of the slide deck

Activity 3: Fighting Food Waste and Reducing Carbon Footprints

EPA Wasted Food Scale image

Activity 4: The Social Impacts of Food Waste

Oh, Scrap! e-reader (digital access or hard copy), 1 per student

Vocabulary

distributor: a company that provides food and non-food products to restaurants, cafeterias, caterers, and grocery stores
economy: the wealth and resources of a country or region, especially in terms of the production and consumption of goods and services
environment: the surroundings or conditions in which a person, animal, or plant lives or operates
farmer: person who owns or manages a farm, cultivates land or crops, or raises animals
food waste: food that is not eaten
processing: in agriculture, the alteration or modification, for the purpose of storage, transport, or sale, of an agricultural product

Did You Know?

Globally, approximately one-third of the food produced for human consumption is wasted, amounting to about 1.3 billion tons each year.
The United States wastes approximately 40% of its food supply, which is about 119 billion pounds of food each year.
Food loss and food waste accounts for up to 10% of global greenhouse gas emissions.

Background Agricultural Connections

Have you ever wondered about the journey your food takes before it reaches your plate? In these lessons, we’ll embark on an exploration of our food system, tracing the path from farm to table while uncovering the crucial connection between food production and food waste.

First, we'll dive into the origins of our food, uncovering the agricultural processes that bring it to life. From planting seeds to harvesting crops, you'll gain insights into the different farming practices that shape what we eat. But it doesn't stop there—our food travels through a global supply chain, linking farmers, processors, distributors, and retailers worldwide. Through interactive discussions and engaging activities, you'll get a behind-the-scenes look at how food is produced, processed, and delivered to us.
But there's a flip side to this journey. As we follow our food from farm to table, we'll also examine the environmental and social impacts of food production. How does farming affect the planet? What role does it play in the growing problem of food waste? You'll explore these questions, learning how every step in the food system contributes to the waste we see today.

Next, we’ll shift our focus to the concept of food waste itself—why it happens, how it affects our environment, economy, and society, and what we can do about it. Through activities, you'll analyze real-life scenarios that showcase the staggering amounts of food that go to waste every day. You'll discover the economic costs, environmental damage, and social issues tied to food waste, gaining a deeper understanding of why reducing waste is so important.

At the end of these lessons, you’ll walk away with a comprehensive view of our food system's complexity and the critical importance of reducing food waste at every stage. You'll not only appreciate the journey your food takes but also feel empowered to make mindful choices that benefit both your health and the planet.

Lesson Activities

Engage

Teach for Clarity

This lesson will have the best clarity if students have a solid understanding of the natural resources required to produce our food. It is recommended to teach the lesson, The Environmental Cost of Food before beginning this discussion on the impacts of food waste.

Preparation

Print and cut out the attached Source Search Pictures showing everyday items. You may also purchase the classroom-ready card deck.
Randomly divide the pictures into two groups. Use two colors of index cards (or card stock) and glue the pictures onto the cards. Laminate the pictures for future use.
Obtain four containers (boxes, plastic tubs, paper box lids, or paper grocery bags) and label each with one of the following: “Stores,” “Factories,” “Farms,” and “Natural Resources.”
Identify a suitable location for a relay race such as an area outside, a wide hallway, or the gymnasium.

Activity: A Search for the Source

Divide the class into two teams. Divide the laminated pictures by color. You should have 18 pictures in each pile. If you are using red and blue index cards, you will have a red and blue team. If you are using the classroom-ready Source Search card deck, you will have a white and black team.
Take the students to the location of the relay race and place each team in a single file line. Be sure to have all the pictures face down in front of the first person in each line. Locate the tubs 20-50 feet away from the lines.
Give students the following instructions: "This is the source relay. Your job is to place each card in the tub representing the original source of the everyday item that is pictured. When you are at the front of the line, pick up a card, look at the picture, then run to and place the picture in the correct tub based on the product’s “source”– either “Stores,” “Factories,” “Natural Resources,” or “Farms.” Keep in mind that you are looking at the product, not the packaging. The next person in line goes when the person in front of them returns and crosses over the start line or hand-tags them. The returning player should go to the end of the line."
- Optional Alternative: Rather than a relay race, you can also play the Source Search Kahoot game or Source Search Quizziz. These online game quizzes may also be used as a formative assessment after the relay.
Ask students if they have any questions and clarify as needed. Begin the relay race and continue until all of the pictures have been sorted. The first team to finish the sort wins temporarily, but the ultimate winner will be determined by accuracy.
After the relay is over and the pictures are sorted, return to the classroom or have the students gather around you in a suitable location to go through the cards and discuss the correct answers. As you hold up each picture, the students can show whether they agree or disagree with the sort using the "thumbs up" or "thumbs down" signal, or another response as chosen. Use the attached Source Search Items Reference List for the correct answers and explanations for each card. You can also refer to the Source Search e-Learning lesson video for a recorded explanation. If you choose to keep score to identify a winner, have a student keep a tally for each team of the cards placed in the correct box.
- Farms: Explain that if the item contains ingredients or raw products from a farm, the item is in the correct box. Examples would be any food items such as cereal, cookies, and milk, or any clothing item made from a natural fiber such as cotton (jeans) or wool (coat). Some items from a farm that are not eaten or worn include paint (this contains linseed or soybean oil) or fuel such as ethanol.
  - Note: After most relays, the “Farms” container will typically have only a few items in it.
- Natural Resources: Explain that items in this tub should be products we get from the ocean, from plants or animals that occur naturally without management from humans, or from mining. Examples of items that should be in this box are: fish or shrimp (wild; however, note that fish and shrimp can also be farmed), cars, salt, water, plastic (plastic starts as oil, which is mined), synthetic fabrics (polyester, petroleum or oil products), computers, cell phones, and any metallic items. Wood products may be in this box, but many wood products come from timber grown on farms. Let the class decide how to divide these. You might decide to “split the difference;” put one (the fish) into the “Farms” box and the wood into the “Natural Resources” box. Remind your students that this is the “source” search. What is the “real” source of the things we use every day? Nearly all are grown or mined – farmed or extracted from the natural world.
  - Note: This tub is also likely to only have a few items inside.
- Factories: Explain that a factory is a place where raw ingredients are changed into the useful items we need or want; wood into furniture, ore into steel for cars, wheat into bread, and potatoes into chips. A factory assembles items to later be sold in a distribution center or store. With this information ask students, "Are there any items that can originally be sourced to a factory?" (No.) Proceed by sorting every card in the “Factories” box into either the “Farms” or “Natural Resources” container. After doing this, your students should understand that all originally sourced products have either been grown or mined.
- Stores: Move to the box labeled "Stores." After receiving the explanation about factories, check for understanding by asking, "What type of things can be sourced to a store?" Students should realize that, like the “Factories” container, nothing should be in the “Stores” container; this is just where we purchase the items, it is not their original source. Clarify that factories and stores rely on raw ingredients from the farm and natural world. Every picture or product should now be in either the “Farms” or “Natural Resources” container.
To increase the level of understanding, ask students, "What natural resources do farms need in order to produce the products used to make all of these items?" (Soil, water, light, and air are natural resources that farmers rely on.) To illustrate, place the “Farms” box inside the “Natural Resources” box.

Explore and Explain

Activity 1: Food System Chains and Food Waste

Provide students with one of the following flowcharts:
- Livestock
- Berries
- Tree Fruits
- Grains
- Livestock
- Nuts
You can pass the same flowchart out to each student or pass out a variety. These flowcharts are available to print yourself (see hyperlinks in step 1 or the Materials list) or can be purchased from the AgClassroomStore.
Ask students to compare what they learned from Source Search and apply it to their flow chart. Facilitate a class discussion:
- Where on your flowchart did farming occur?
- Were any natural resources needed at any stage during the flowchart?
- What kind of natural resources were used? Oil, water, soil, etc.
Direct students’ attention to the food items produced on their flow chart.
Now ask students to consider food waste.
- What is food waste?
- Is food waste a problem in the United States?
As you point to the flowchart, ask students, “What happens when we waste the food items at the end of the flow chart?”
Explain to students that when food is discarded prematurely, we not only waste the food itself but we also waste time and natural resources that were used at every stage of the farm-to-fork process.
- Pick a food item on the flow chart (e.g., hamburger on the livestock flowchart)
- Ask students, “If you only eat half of a burger and throw the other half away, in addition to food waste, what natural resources were wasted as well?” (water that was used for livestock, grass used to feed cattle, oil used for fuel to transport cattle, time and labor stocking beef on grocery store shelves, etc.)
If needed, consider using slides 19-24 of the Exploring Origins: Where Our Food Comes From slide deck for additional information on the food system chain.

Activity 2: Food Waste's Impacts on the Environment

Consider using slides 6-9 of the Food Waste: Impact on the Environment slide deck to review food waste.
Explain to students that about 33% of the United States’ food supply becomes waste, which is about 77.6 million tons.
Now that students have discussed and considered food waste’s impact on the food systems chain, ask students, “Does food waste only occur during the consumption stage?”
Allow students to share ideas.
Explain to students that food waste can occur at any point between production and consumption due to spillage, breakage, degradation during transportation or handling, or waste during the distribution, retail, and consumption stage.
Ask students what happens when food waste is wasted further down the line? If food is wasted further down the food supply chain, this results in higher environmental impacts.
Now ask students, “In what ways does food waste impact our environment?”
Allow students to share thoughts on how food waste affects the environment.
As a class, watch Food Waste: The Hidden Cost of the Food We Throw Out.
After watching the clip, discuss the following questions with students:
- How does food waste contribute to environmental degradation? What specific aspects of climate change are exacerbated by food waste?
- How does food waste differ between developed and developing countries? What factors contribute to these differences?
- What strategies are proposed in the video to reduce food waste? Which do you think would be most effective?
- How can we contribute to reducing food waste in our homes, schools, and communities? What changes might be challenging to adopt?
Using slides 7-8, discuss food waste and its impact on water.
Project slide 9 on the board and ask students to consider the amount of water needed to produce the foods we eat.
Use slides 10-12 to discuss the amount of water needed to produce common food items.
- Note: To elaborate more on water needs, see Water Needs for Food Production.
Ask students to now consider food waste's impact on water.
Using slides 13-15, discuss leachate and eutophication with your students.
Using slides 16-18, discuss how food waste impacts wildlife.
- Ask students to consider the different impacts that habitat loss can have on an ecosystem. Allow students to share thoughts.
- Ask students, “What is biodiversity?” Explain to students that biodiversity is all the different kinds of life you’ll find in one area—the variety of animals, plants, fungi, and even microorganisms like bacteria that make up our natural world. Each of these species and organisms work together in ecosystems, like an intricate web, to maintain balance and support life.
- Explain that if we make improvements with our use of food (using food more effectively and mitigating food waste), we will lessen the demand for new farmland to be created and habitats to be destroyed.
Using slides 19-22, discuss food waste’s impact on the climate.
Project slide 23 on the board. Ask students to consider their food footprint, or “foodprint”. Does the food we eat have an impact on the environment?
Using the Harvard Foodprint Calculator, allow students to calculate their individual “foodprint” (or complete this class as an activity).
Allow students to input their information on the calculator to get data on their annual carbon, nitrogen, and water emissions.
Ask the class to report their numbers for carbon. Who has the lowest number? Who has the highest? Ask students to consider ways they could decrease their “foodprint”.

Activity 3: Fighting Food Waste and Reducing Carbon Footprints

Project slide 24 on the board, or have students turn to page 5 of the Oh, Scrap! e-reader.
Introduce the EPA’s Wasted Food Scale and explain there is a preferred order of what happens to uneaten food.
Ask the students to consider ways they can reduce their carbon footprint and fight food waste.
Allow students to consider their most recent meal:
- What did they eat?
- How was the food produced?
- Which food item(s) did you eat completely?
- Did any food get wasted?
- Where on the Food Recovery Hierarchy diagram, where did the wasted food end up? How far down the hierarchy did your wasted food go?
- How can you ensure that the food you eat does not end up in the land fill?

Activity 4: The Social Impacts of Food Waste

Begin by writing “Food Waste” and “Food Loss” on the board.
Ask students, “Is food waste the same as food loss?”
Using “think-pair-share,” allow students to come up with definitions for each term.
Write statements and ideas below each term.
Direct students to page 3 of Oh, Scrap!
Discuss the differences between food waste and food loss.
As a class or individually, read through pages 3-4, and ask students to consider the social impacts of food waste.
Explain to students that food waste and hunger are directly related.
Point out to students that in high-income countries, food waste is more prevalent, and in low-income countries, food loss is more prevalent. Why is this?
- Direct students to this article: 5 Facts About Food Waste and Hunger to further discuss the differences between food waste and food loss in countries
- Which fact surprised students the most?
Students may now be wondering how they can make a difference with such a huge global issue.
Discuss the importance of lowering food waste and being thoughtful of what they buy.

Elaborate

Follow this lesson with Fighting Food Waste: Strategies and Solutions for Home and School where students can create plans to decrease food waste at home and school.
Start a classroom vermicomposting bin for students to observe and utilize. Allow students to bring food scraps from the lunchroom to the vermicomposting bin to prevent food from ending up in landfills.
- Complete the Competition Compost activity. This will guide students on what food scraps can and can’t be composted.
For more information, recipes (for wasteless recipes), and videos, visit the Nourish Smart website.
Explore the concept of food miles with an activity to calculate the distance common meals travel to you.

Evaluate

Lead a class discussion with your students. Ask students to consider food’s impact on earth.
Introduce students to the acronym “E-S-P-eN” and explain what each letter represents.
Discuss concepts from the lesson and discuss the economic, social, political, and environmental impacts of food waste.
Review and summarize the following key concepts:
- Food is produced on a farm or from natural resources. When we waste food, we waste many resources including money, time, labor, energy, land use, transportation, water, and more.
- We can mitigate food’s impact on the environment by not allowing food to end up in landfills. This can be done by donating or upcycling food, feeding food scraps to animals, or composting feed scraps.
- There is a difference between food waste and food loss. Food waste is more common in high-income countries and food loss is more prevalent in low-income countries.

Recommended Companion Resources

Poster/Infographic • Creative Solutions to Ending School Food Waste
Kit • Environmental Cost of Food Kit
Poster/Infographic • Environmental Footprint of Food Poster
Book • Food for the Future: Sustainable Farms Around the World
Booklet/Reader • Oh, Scrap
Movie/Video • What is Regenerative Agriculture?
Movie/Video • What is Sustainable Agriculture?

Credits

Author

Carson Johnson, Palak Gupta, and Bekka Israelsen | Hunger Solutions Institute at Utah State University

Standards

National Content Area Standards

Science
- HS-ESS3: Earth and Human Activity
  - HS-ESS3-4: Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.
  - HS-ESS3-3: Create a computational simulation to illustrate the relationships among the management of natural resources, the sustainability of human populations, and biodiversity.
- APES Unit 5: Land and Water Use
  - EIN-2.N Ecological Footprints: Explain the variables measured in an ecological footprint.

Agricultural Literacy Outcomes

Agriculture and the Environment
- Evaluate the various definitions of “sustainable agriculture,” considering population growth, carbon footprint, environmental systems, land and water resources, and economics (T1.9-12.f)
Culture, Society, Economy & Geography
- Discuss how agricultural practices have increased agricultural productivity and have impacted (pro and con) the development of the global economy, population, and sustainability (T5.9-12.e)
Food, Health, and Lifestyle
- Explain how food production systems are influenced by consumer choices (T3.9-12.f)

Common Core Standards

Anchor Standards – Language
- CCSS.ELA-LITERACY.CCRA.L.6: Acquire and use accurately a range of general academic and domain-specific words and phrases sufficient for reading, writing, speaking, and listening at the college and career readiness level; demonstrate independence in gathering vocabulary knowledge when encountering an unknown term important to comprehension or expression.
Anchor Standards – Reading
- CCSS.ELA-LITERACY.CCRA.R.6: Assess how point of view or purpose shapes the content and style of a text.
Anchor Standards – Speaking and Listening
- CCSS.ELA-LITERACY.CCRA.SL.1: Prepare for and participate effectively in a range of conversations and collaborations with diverse partners, building on others’ ideas and expressing their own clearly and persuasively.

We welcome your feedback!

Ask a question or report a problem: If you have a question about this lesson or would like to report a broken link, please send us an email at matrixelearning@gmail.com.
Share your experience: If you have used this lesson and are willing to share your experience, we will provide you with a coupon code for 10% off your next purchase at AgClassroomStore.
Share Your Experience