The Carbon Footprint of Food

This lesson shows that different foods have different environmental impacts. Students will calculate ratios and practice proportional thinking. 

Step 1 - Inquire: Students explore an interactive bar graph showing the resources it takes to create our food.

Step 2 - Investigate: Students select different foods that they wish to compare. Students complete a series of mathematical calculations showing their knowledge of arithmetic and ratios.

Step 3 - Inspire: In groups, students discuss what they have learned and answer several questions.

Positives

• This lesson is great because it shows that different foods have different environmental impacts.
• It shows the great disparity between certain types of foods. For example, creating 1 kg of beef (from a beef herd) emits 99.48 kgCO₂eq. Creating 1 kg of potatoes creates only 0.46 kgCO₂eq. Raising beef creates more than 200x the carbon dioxide than raising the same amount of potatoes!

Additional Prerequisites

• You will need to share the Student Slideshow with students and grant them editing rights. They will all be writing in the same slideshow.

• In general, animals and animal products use far more resources than plants.
• Kilograms are used in this lesson. Some students will be unfamiliar with this unit. You can read more about the kilogram at Britannica. An easy conversion from kilograms to pounds is 1 kg = 2.2 lbs.
• Kilograms of CO₂ equivalent are also used in this lesson. This is pretty abstract for the students. You can have them imagine holding a 2.2-pound ball in their hands. This ball has mass and takes up space. This is the "pollution" generated when creating different foods.

Differentiation

• You can create groups of students with mixed abilities.

• If a group finishes early, you can ask these extension questions:
  • "Food 1’s emissions are what % of food 2’s emissions?"
  • "Can you convert your answers from kilograms to pounds?"
• The Investigate section features a completed table of calculations. You can use this before the students begin their calculations. You can also share this with certain students or groups and let other groups complete their calculations on their own. Another option is to have students use the completed table to check their thinking when they are finished. There is a walkthrough of calculations in the speaker notes of this slide.

This lesson is thoroughly sourced. It is engaging and suitable for students to understand how to measure carbon footprint from food sources. The activities in the lesson would also enable them to build their quantitative skills to determine the extent of CO₂ impact on the environment. The lesson has passed our science review, and it is advised for classroom use.

Primary Standards

• Common Core Math Standards (CCSS.MATH)
  • Ratios & Proportional Relationships (6-7)
    • CCSS.MATH.CONTENT.6.RP.A.1 Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities. For example, "The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2 wings there was 1 beak." "For every vote candidate A received, candidate C received nearly three votes."
    • CCSS.MATH.CONTENT.6.RP.A.2 Understand the concept of a unit rate a/b associated with a ratio a:b with b ≠ 0, and use rate language in the context of a ratio relationship. For example, "This recipe has a ratio of 3 cups of flour to 4 cups of sugar, so there is 3/4 cup of flour for each cup of sugar." "We paid $75 for 15 hamburgers, which is a rate of $5 per hamburger."
    • CCSS.MATH.CONTENT.6.RP.A.3 Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.
    • CCSS.MATH.CONTENT.7.RP.A.2 Recognize and represent proportional relationships between quantities.

Supporting Standards

• Common Core Math Standards (CCSS.MATH)
  • The Number System (6-8)
    • CCSS.MATH.CONTENT.6.NS.B.3 Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation.
    • CCSS.MATH.CONTENT.7.NS.A.1 Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram.
    • CCSS.MATH.CONTENT.7.NS.A.2 Apply and extend previous understandings of multiplication and division and of fractions to multiply and divide rational numbers.