LESSON SUMMARY This activity introduces the concept of virtual water that is embedded water in our food. Students will explore the implications of importing and exporting virtual water and will use a country’s water footprint as a way to explain water self-sufficiency. FOCUS QUESTION How do our food choices affect our overall water consumption? BACKGROUND According to the Canadian Water Governance group, the water Canadians use for washing, cooking, flushing the toilet and drinking add up to about 331 litres per day.1 Many of us don’t realize however, that without thinking about it, we also consume hundreds of thousands of litres of water that is embedded in our food, clothing and other products. This water use contributes to our overall water consumption, or water footprint, and is called virtual water. The concept of virtual water was first put forth by Professor John Anthony Allan as a means to quantify the amount of water that is used in the production of a good or service.2 The Water Footprint Network suggests that the water used in production is said to be ‘virtual’ because it is no longer contained in the final product. For example a standard microchip contains about 32 litres of virtual water, but this water is not physically sitting in our computers. Virtual water takes into account the total amount of water used throughout each step of production.3 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 1 Accounting for virtual water becomes extremely important when we consider issues around food production and distribution. While calculating the precise volume of virtual water in products is difficult, the concept encourages us think about water differently – a few litres of water are wasted when you take a long shower, but hundreds (or even thousands!) of litres of water are wasted when you throw away food. Some common virtual water values are listed below. Approximate Volume of Water Used for Growing, Harvesting, Processing, etc. 1 glass of milk = 200 litres of water 1 orange = 50 litres of water 1 slice of bread = 40 litres of water 1 apple = 70 litres of water 1 glass of apple juice = 190 litres of water 1 bag of potato chips = 185 litres of water 1 glass of orange juice = 170 litres of water 1 hamburger = 2400 litres of water 1 egg = 135 litres of water 1 kilogram of beef = 15500 litres of water 1 cup of coffee = 140 litres of water 1 kilogram of chicken = 3900 litres of water 1 cup of tea = 30 litres of water 1 kilogram of goat meat = 4000 litres of water 1 potato = 25 litres of water 1 kilogram of soy beans = 1800 litres of water 1 tomato = 13 litres of water 1 kilogram of sugar = 1500 litres of water From: www.waterfootprint.org Measuring our “ecofootprint,” allows us to quantify our overall impact on the environment in terms of how many hectares of land required to maintain our lifestyle. Recently, the concept of measuring our “water footprint” has also become prevalent. The “water footprint” of a country, organization or person, is defined as, “the total volume of freshwater that is used to produce the commodities, goods and services consumed” by the country, company or person.4 In Canada, our water footprint is 204.9 m3 water/capita/year (or 204900 litres/person/year); significantly higher than most other countries around the world.5 Tracking the volume of virtual water that is contained in the foods we produce, export, import, and eat allows us to tackle water issues on local, national and global scales. It means that as a global community, we can adjust our trading practices to allow areas with less water to gain access to foods (and other products) with higher water requirements by importing them from areas with high rainfall and increased access to water. The hope is that water-scarce regions can then in turn, export crops that are less water intensive, thus requiring less water for domestic agriculture and allotting more water resources for drinking and sanitation. UNESCO (United Nations Educational, Scientific and Cultural Organization) estimates that we have already reduced our global use by 5% simply by managing virtual water more efficiently.6 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 2 TRACKING THE WATER ON YOUR PLATE 1. Have students complete PART ONE of “The Puddle on your Plate” question sheet and record their answers individually. 2. In pairs, students should discuss their answers and select one of the food items (or one component of a food item) from their list that was imported to Canada from elsewhere in the world. 4. Explain the concept of virtual water, by highlighting some examples of virtual water values in common foods and discussing virtual water management between nations based on food imports and exports. You can begin by showing the “A Comprehensive Introduction to Water Footprints” slideshow available from the Water Footprint Network at www.waterfootprint.org/?page=files/TM_Presentations. Ask students to consider the stages of production for the food item they have selected. Where is water being used? How might virtual water be embedded into this item? 5. Ask students to then consider the national water footprint for the country that produces their selected food item. Logging onto the Water Footprint Network website at http://www.waterfootprint.org/?page=cal/waterfootprintcalculator_national will allow students to calculate the external water footprints of various countries. The water footprint of a nation refers to the total amount of water that is used to produce the goods and services consumed by the inhabitants of the nation. The total water footprint of a country includes two components: the part of the footprint that falls inside the country (internal water footprint) and the part of the footprint that is drawn from other countries in the world (external water footprint).7 Because Canadians import rice from India, the amount of virtual water contained in the rice is factored into the external portion of Canada’s national water footprint. Canada’s external water footprint represents 20% of our total national water footprint, meaning that we are a relatively water-rich country and 20% of the virtual water we consume is shipped to us in products from other countries. 6. In pairs, ask students to discuss, investigate and research the questions outlined in PART TWO of the “The Puddle on your Plate” worksheet and record their answers. 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 3 7. Next, ask students to form groups of 4 or 5 and create a “Virtual Water Menu” that features the food items they selected and the water footprint information collected about the food’s country of origin. Invite students to be creative in choosing the menu’s content, theme and layout. The Virtual Water Menus could include: - images, icons, symbols, graphs or other visual representations that symbolize water content of the foods offered - maps to show where the menu’s foods came from and where it travelled, - the water footprint of the foods’ countries of origin, - the water availability in those countries - a variety of media. EXTENSION QUESTIONS Environmental issues are often presented within a “doom and gloom” context that can leave us feeling overwhelmed and depressed. How would you share what you have learned about the connections that link our food consumption and our water consumption in such a way that inspires and motivates others to take action? There is no global consensus on the importance of tracking virtual water as it moves from one country to another? Why do you think some countries would oppose this type of measurement? How could tracking virtual water imports and exports be problematic? ASSESSMENT AND EVALUATION 4 3 2 1 Organization Information in the menu is very organized. Information is organized. Information is somewhat organized, but it is difficult to follow the flow of the menu. The information appears to be disorganized. Quality of Information clearly relates to the main topic. It includes several supporting details and/or examples from a variety of sources. Information clearly relates to the main topic. It provides some supporting details and/ or examples from some sources. Information clearly relates to the main topic. No details and/or examples are given. Information has little or nothing to do with the main topic. Diagrams and illustrations are neat, accurate and add to the reader’s understanding of the topic. Diagrams and illustrations are accurate and add to the reader’s understanding of the topic. Diagrams and illustrations are neat and accurate and sometimes add to the reader’s understanding of the topic. Diagrams and illustrations are not accurate OR do not add to the reader’s understanding of the topic. The relationship between the variables is discussed and trends/ patterns logically analyzed. Thoughtful conclusions are drawn based on the outcome of the activity. The relationship between the variables is discussed and trends/ patterns logically analyzed. Superficial conclusions are drawn based on the outcome of the activity. The relationship between the variables is discussed but no patterns/trends are identified. The relationship between the variables is not discussed. Information Diagrams & Illustrations Discussion Questions 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 4 Action: Change within Yourself Go meatless! Producing meat (especially beef) requires significantly more water than soy beans and other crops. Limiting your consumption of meat will reduce your overall virtual water use. Be sure that you reduce your meat consumption in a healthy way by supplementing your diet with other protein and iron-rich foods such as tofu, spinach and broccoli. Empty your plate! Sometimes our “eyes are bigger than our stomachs”, but throwing away food not only wastes energy and natural resources but it can also be the equivalent of pouring thousands of litres of water down the drain. Action: Change within Your School Increase Awareness! Host a school-wide screening of a water-themed documentary. A World without Water is a fantastic video that can be downloaded for free online. Other great titles include Waterlife, FLOW and Running Dry. Support local food at school! Does your school or school board have a local food procurement policy? Is it being implemented? If one doesn’t exist, what could be done to initiate the process? Action: Change within Your Community Support local farmers! When local food is in season, neighbourhood farmers’ markets are the best places to buy groceries that haven’t travelled great distances to arrive on your plate. Most farmers’ markets are listed online and many even run year-round! 1 www.watergovernance.ca/factsheets/pdf/FS_Water_Use.pdf 2 waterfootprint.org 3 Ibid 4 www.traumkrieger.de/virtualwater/ 5 Ibid. 6 waterfootprint.org 7 www.waterfootprint.org 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 5 PART ONE 1. What did you have for dinner last night? 2. Which item of food was your favourite? 3. What is the country of origin of your favourite food item? Where was is produced? If you don’t know the answer to this, how could you find out? 4. What are some of the ingredients in your favourite food item? 5. Where did these ingredients originate? Ingredient Country of Origin 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 6 PART TWO 1. What was the external water footprints of the countries you identified? 2. At first glance, would these countries be considered to be water-rich or water-scarce? Why? 3. Does the external water footprint of the countries you selected help to explain whether they are water-rich or water-scare? If so, how? If not, why? 4. What other factors (geographic, economical, social, environmental, etc.) might be involved in calculating a country’s external water footprint? 5. What are some ways that your selected countries could decrease their external water footprints while continuing to meet their water and virtual water needs? 6. How could these countries achieve water self-sufficiency? Is water self-sufficiency a realistic goal for these countries? Explain your rationale. 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 7 2010 © Toronto and Region Conservation, Permission to reproduce this page is granted for classroom use only. 8