Have Food, Will Travel (2 of 3)

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Students will be able to: 1) map the pathways of commonly eaten foods in New York; and 2) calculate the hidden costs of food, such as greenhouse gases and energy use.

Big Idea

The food consumed during a typical New York City dinner may have traveled over 10,000 cumulative miles. How might we use our understanding of the costs and benefits of global food distribution to identify aspects of the food system to redesign?

FRAME: Environmental impact

In the previous lesson, students made observations of the industrial food system, developed explanations for the necessity of food travel, and began to explore the connection between local food systems and global food production.  To do this, students collaboratively developed public presented solutions to a design challenge, and fleshed out individual, evidence-based explanations for some aspect of the food system.   At this point, students should be able use appropriate evidence to explain why food travels and how the local food system connects to broader global food distribution.  

In this second lesson, students learn to evaluate the environmental impact of food systems through quantitative analyses of case studies.  To meet this goal, students first engage in a college style lecture that provides an overview of food distribution and transport.  Students will then complete a "data lab" activity that explores the environmental impact of transported food.  In this activity, students will carefully map the transportation and distribution of a chosen food product, calcualte the carbon and fossil fuel footprints of this food product, and apply this analysis to their own diet.  By the end of this second lesson, students should be able create a transportation and distribution map of a food product and calculate the environmental impact of that food.

RESOURCE NOTE: Attached is a prototype activity guide that teachers might want to modify for the learning activities in this sequence of lessons.

EXPLAIN: Food transport

15 minutes

What is the purpose of this activity?

Students actively engage with a brief college style lecture.  The teacher directly communicates important information using an adapted version of slides from the Johns Hopkins Center for a Livable Future.  Although this course is problem-based and student co-created, the ability to experience a lecture with deep focus and critical thinking will be essential for students going to college.  Additionally, because a major focus of this unit is public presentations, this lecture is an opportunity to debrief a teacher's model demonstration.  To this end, teachers may want to differentiate a college lecture experience for the unique presentation needs of various student groups.  If, for instance, students struggle with creating powerful visuals, this should be a focus of the teacher's lecture.  If students struggle with eye contact and storytelling, this should be a focus of the teacher's lecture.  This focus should be transparently communicated to students as a frame for interacting with the lecture.

What will student do?

Students engage with this lecture in two ways.  First, students follow a content track.  They record information and attempt to develop answers to the following key questions:

  • Why do humans transport food over long distances?
  • Exactly how far does food travel?
  • What are the implications of food traveling over long distances?
  • What are the strengths and weaknesses of the current food system?

The content track will be a review and extension of the key objectives from the previous lesson.  Second, students follow a presentation track.  They note moves the teacher make that are improvements over the presentations given by student groups during the previous lesson.  This is an open-ended track; students are merely asked to note differences that would be useful for students to incorporate into future presentations.  However, if guiding questions are needed, teachers might suggest the following:

  • How does the teacher hold students' attention?
  • How does the teacher explain ideas clearly?
  • How does the teacher use visuals to support ideas?

After the teacher-centered lecture, all students will engage in an open discussion about content and presentation.  This discussion will bias towards the nature of the presentation, as most of the content is review from the previous lesson.

What will the teacher do?

The teacher will deliver a short college lecture using the attached slideshow (modified as necessary).  The teacher will also facilitate a whole class conversation about the experience of the lecture.  How was this lecture different from presentations yesterday?  What did you notice about how I explained difficult concepts?  When did I do a poor job of holding your attention?  What could I have done better?  What did you like about this presentation?  Students should leave this discussion with one actionable that they can make to improve their next presentation.  Students may want to form future groups based on similar presentation needs.

ELABORATE: Food miles "lab"

40 minutes

What is the purpose of this activity?

Students will explore the movement of food and food ingredients from the "field to the plate."  Students will also calculate food miles and the costs to society of food miles.  This lab operationalizes food miles as energy use and greenhouse gas emission.  Teachers gather formative assessment data.  Where are students confused?  What can students do with little help?  What concepts are misunderstood?  What skills need to be developed?  By the end of this activity, students should be able to draw an accurate, annotated map of the food distribution routes for a food product.  Students should also be able to calculate the environmental impact of this distribution network in terms of energy use and greenhouse gas emissions.

TIMING NOTE: As with many activities in this three lesson sequence, the food miles data lab might take students more than one period to complete.  Especially for students that have underdeveloped math skills, explicit teacher modeling and additional time will be necessary.

RESOURCE NOTE: For additional food miles background, see the attached reading in this section.

What will students do?

Student teams will create maps and data sheets for strawberry yogurt or beef or a food item of their choice.  Students will also calculate the energy expense and greenhouse gas emissions for transported food.  See the attached PROTOTYPE ACTIVITY GUIDE for more detailed instructions.  The following is an excerpted description of the procedure that students will follow:

1. On your U.S. map, mark each point along transport routes. Use an appropriate symbol to mark the point. For example, if the point is a berry farm, you could draw a berry.

2. On your U.S. map, draw the transport routes between each point using arrows. Work as a group to determine where the routes are and in which direction they should go. (Pro tip: The last distribution route should end at a retail store.)  Use different types of lines (dotted, dashed, colored, etc.) to represent different modes of transport. Assume food is transported over land in a truck unless you know the food is traveling along a major rail route.

3. Using a ruler and the scale provided on your map, calculate the mileage of each transport route.  You may also use an online map program.

4. Write the mileage next to each route. Remember to include units (km).

5. Create a legend on your map that explains what each symbol represents and what different types of lines represent.

6. When investigating how far food is transported, you also have to consider how much food is being moved. Remember, the heavier the shipment, the more energy is required to move it. Using the clues given on your Data sheet, calculate the weight of each shipment. (Pro tip: Start from the final product and work backward.)

7. On your map, write the weight of each shipment next to its route. Include units (kg).


8. Copy the following information from your completed map onto your Food miles worksheet: Each route, the mode of transport, the weight of the shipment (measured in kilograms) and the distance of that route (measured in kilometers). Write your results in the first three columns.

9. For each route, multiply the weight of each shipment times the distance (measured in kilogram-kilometers). Write your results in the fifth column of your Food miles table.

10. Using the table below as reference, calculate the energy required to move each shipment along each route (measured in kilocalories). Write your results in the sixth column of your Food miles table.

11. Using the table below as reference, calculate the greenhouse gas emissions created by moving each shipment along each route (measured in grams of carbon dioxide equivalents). Write your results in the seventh column of your Food miles table.

12. In the final two rows of your Food miles worksheet, calculate the total energy use and greenhouse gas emissions associated with transporting your product.


What will the teacher do? 

The teacher will circulate to each group to assist with modeling of appropriate distribution paths, calculations, questions, and solutions ideas.  The key teacher move in this activity, however, is to push as much as the cognitive load onto students as possible through collaborative groupings.  Have you asked David for help?  I hear he has a great understanding of how to figure out the carbon footprint of sugar!  There will almost always be a few students that are able to explain aspects of this lab to their peers.  Building a network of informal student experts is far more effective than having an individual conversation with every student.  

Additionally, another key teacher move is to honor students' solution pathways.  Many students will want to pursue what can seem like irrelevant pathways.  That's Idaho?!  Oh I always wanted to visit a farm.  Let me Google a picture of that.  This sort of exploration, if brief, is actually a very positive sign of student engagement.  Students will eventually calculate fossil fuel use of transported beef (or another food) if they are given some freedom to learn about topics in this activity that they find interesting.  Students will opt out, however, if this activity simply feels like a means to developing students' ability to calculate environmental impact.  Teachers would be wise to respect students' process, even if this process takes them off track for a few minutes.  Many students, especially students in an urban environment, have never seen a farm and have limited geographical expertise.  The absence of students wanting to go "off task" should actually be seen as a red flag.  Engagement in this activity will mean that students will, at some point, become sidetracked.  Educators should encourage this behavior, so long as it does not become the focus of the lab.  A good rule of thumb is that students can explore for no more than three minutes before returning to "real" task.

EXIT: Next steps

Students will be at different points in the ELABORATE activity at the close of the class.  Even so, all students should have enough practice to apply the framework of the data lab to their personal lives. As an assignment to be completed outside of class, students should spend no more than 15 minutes creating a food map of their favorite meal.  They do not need to do research; if they are unsure about the transportation networks, they may imagine it.  This activity allows students to review and practice the skills from the data lab and to complete initial work for the opening activity for the next class.  In order to complete this task, students should be able to successfully map the pathways of food.  They will practice calculating the environmental impact of this food during the next lesson.