Module III Section C Activities
Activities for Module III Fur, Feathers, and Fins – Animals in our food
Activities for Section C: Animals in the Agro-ecosystem
Activity 1: Water and Numbers
Part 1. How much water does it take to produce a pound of beef?
Part 2. How much water do you use at home?
Part 3. Concluding discussion
Purpose: Students will explore the impacts of animal agriculture on water, consider regional differences in water use, and begin thinking critically about statistics.
Advance preparation:
Advance preparation: Use information from the National Geographic water use calculator and ask students to bring in copies of their water bills if they are on public water supply (Note: Access to the National Geographic calculator requires an email which puts users on the mailing list)
Estimated time: Part 1: 20 minutes, Part 2: 30 minutes, Part 3 (concluding discussion): 15 minutes
Background information: One common criticism of meat production is that it uses a lot of water compared to other agricultural products.
Estimates of how much water meat production takes vary widely, but even conservative estimates make beef a pretty water-intensive food.
Part 1: How much water does it take to produce a pound of beef?
Divide the students into small groups. Give each group the three water use estimates. Have each group discuss and answer the questions in this worksheet (PDF Download).
Key to discussion questions in above worksheet link:
- Which calculation do you think is the right one? All three estimates may be roughly valid since they are measuring different things. It depends on how they are used.
- What difference does it make whether the water to grow the feed comes from rainfall or irrigation? If water comes directly from rainfall, then how it acts in the environment is not changed that much by the fact it is helping food for cattle to grow, especially if the food is well managed pasture, not treated with fertilizers or pesticides. If the water is irrigation water, then its use will have much greater environmental impacts.
Much of the forage and grain fed to beef produced in the western US is grown using irrigation. Some of this irrigation water is pumped from aquifers at unsustainable rates. Some water is diverted from river systems, altering aquatic communities and reducing the water available for other uses. For example, about 70% of the water taken from the Colorado River in California, Arizona, and Nevada is used for agricultural purposes. Long before the Colorado River reaches its historic outlet to the ocean in Mexico, it has completely dried up, because its natural flow has been diverted for agricultural use. Some of the water withdrawn goes to fruit and vegetable production, but livestock production is a major water user accounting for around 55% of the agricultural water usage.
In Wisconsin and Iowa, in most years rainfall is adequate for forage production, and very few farmers irrigate pastures, hayfields, or feed crops. However, farmers do withdraw water from streams and wells to provide drinking water for their animals, as well as water for washing milk rooms and other animal production facilities. This agricultural use can have impacts on some local water supplies or aquatic systems.
- Does it matter how the irrigation is handled? Why and how? How the irrigation is handled matters a lot. For the environment it matters how much water is withdrawn from natural water courses and how efficiently the water is used. For example, if half the water is lost in transport (not uncommon), then actually double the amount of water used for irrigation had to be taken away from a river or stream. If the irrigation water is applied in the same small watershed that it was taken from, at least some of it will be returned to the river or stream. If it is applied in a different watershed, all the water is lost to the original water source. It also matters for social reasons. For example, if upstream users take all the water they want, there may be none left for downstream users.
- Why do you think the Beef It’s what’s for Dinner corporation uses the figure of 308 gallons? Why do many environmental organizations use the higher figures such as those estimated by PETA? Why does it matter how much water it takes to produce a pound of beef? The National Cattlemen’s Beef Association wants people to think that beef production is environmentally benign, so they choose the lowest estimate. In addition, the association may wish to protect certain regional interests. Using a national average obscures the differences in environmental impact caused both by geography and by the production system.
Environmental organizations want people to realize how high the environmental costs of beef production can be, so they use the higher figure. Unfortunately, by doing so, they imply that all beef production has a level of environmental impact that in fact only some producers have.
The amount of water used in beef production is important when it has negative impacts on the environment or on access to water for other uses. Of course, livestock production can damage the environment in other ways than water use.
- Do you think water requirements for beef production have changed? Why or why not? Since there are no newer estimates, we can’t be sure whether or how water use for beef production has changed. However, it is likely that it has not changed much, if at all. Agriculture’s use of water for irrigation has been stable over the last 10 years, though there are some annual fluctuations due to weather. While there have been some improvements in irrigation technology, there has also been an increase in the acreage under irrigation, perhaps due to climate change. (See USDA ERS – Irrigation & Water Use )
Part 2: How much water do you use at home?
The purpose of this part of the activity is two-fold: First, students will get a sense of household use of water, which they can then compare to agricultural water use, and especially that needed for beef production. Second, students will realize how difficult it is to estimate water use, and how much use varies.
Have students use the water bill information to compute average weekly household use. (Take number of days covered by billing period and divide by 7 to get the number of weeks in the billing period. Then take the figure for total water use and divide that by the number of weeks in the billing period.) Compare the information on the water bills with the students’ estimates from the water use charts.
Now have students take 5-10 minutes to use this tool and estimate their household and personal water usage then have them compare with others.
Water Calculator | Home Water Works (home-water-works.org)
Note that the estimated amounts on the calculator that let’s students include the efficiency of appliances and about how people use them. If students have better information about their own household appliances, they can use this for more accurate information.
Part 3. Concluding discussion
Share the water facts and figures with the students. Discuss the questions from Part 1 of this activity with the class, along with the questions below, in light of what students learned from doing their own water use assessment and considering the information in the water facts and figures.
How does use of water for beef production compare with other food production? With other consumer products?
Even using a more conservative estimate, beef is an intensive water user compared to other foods. However, where and how the beef is raised can make an important difference in how much water it uses.
Although industry uses water too, agriculture accounts for more use, and unlike industry, most agricultural use is not returned to the same watercourse.
What can we learn about numbers and statistics from this exercise?
First, it is not easy to generate accurate statistics. Second, averages obscure significant variations. Third, it is important to know what assumptions were made in generating a number in order to know how that number should be used.
How could you design a beef production system that would have relatively little impact on water supplies?
A system that relies on non-irrigated pasture and feed will have comparatively little impact on water in the environment and water supplies.
Water Facts and Figures
According to the EPA:
- The average US household uses about 300 gallons/day or 109,500 gallons/year of water. On average about 70% of water is used indoors with the remaining 30% is used outdoors. However, outdoor water use is much higher in drier parts of the country. The average US individual uses around 82 gallons per day.
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- Keep in mind these statistics use averages from across the US. Water use tends to be higher in dry areas, mainly because of landscape watering.
- Water use estimates vary across states
- In households not utilizing water-efficient fixtures, toilets used the most daily water (19-24 gallons per person per day). Clothes washers were the second largest water users (15 gallons per person per day) and showers were third (20 gallons per person day).
- In households that utilized water-efficient fixtures, clothes washers assume the role of top water user (14 gallons per capita per day), water efficient faucets tend to decrease water use by 30% (10.9 gallons per capita per day), shower water usage decreases by around 60% (10 gallons per capita per day) and toilet water usage falls by 20% (9.6 gallons per capita per day).
How is Most Freshwater in the US Used?
As of 2015, daily water use across the USA was 322 billion gallons. Freshwater use accounted for around 87% of water withdrawals. Surface water taken from lakes, rivers, and reservoirs accounted for over 61% of daily water usage while ground water was about 25%.
The main two uses, irrigation and thermoelectric-power production, accounted for about 78 percent of water used in 2015. Here’s the breakdown by water-use category:
- Irrigation: 37 percent
- Thermoelectric power: 41 percent
- Public Supply: 12 percent
- Industry: 5 percent
- Livestock, aquaculture: around 3 percent
- Domestic (self-supplied): 1 percent
- Mining: 1 percent
(Source: University of Michigan)
The large amount of water used for power production (electricity) is mostly used to cool the heated power-production equipment. The vast majority of the water used by power plants is returned to the environment, and thus is available for other uses. In contrast, irrigation water is not available for other uses.
In Wisconsin, however, the breakdown of water use is a little different:
- Thermoelectric: 80 percent
- Industrial: 5 percent
- Domestic: 1 percent
- Agricultural Irrigation: 5 percent
- Public Use: 6 percent
- Non-irrigation Agriculture: 2 percent
- Commercial: less than 1 percent
(Source: USGS Geological Survey)
The average American individual uses 80 to 100 gallons of water at home each day. However, water use greatly increases when the food we consume is considered. Most agricultural products have high water uses that most consumers don’t consider.
Water required to produce common of agricultural commodities:
- 1 lb. lettuce: 30 gallons
- 1 lb. tomatoes: 26 gallons
- 1 lb. wheat: 25 gallons
- 1 lb. carrots: 33 gallons
- 1 lb. watermelon: 50 gallons
- 1 lb. apples: 49 gallons
- 1 lb. chicken: 518 gallons
- 1 lb. pork: 718 gallons
- 1 lb. beef: 1,800 gallons
It’s important to note that water use in crops varies by region and how water use itself is measured. The numbers above are just estimates and are subject to change depending on climate and region.
Water quotes:
“Agriculture accounts for 70 percent of the planet’s freshwater withdrawals annually. This presents a tremendous opportunity to work with farmers and agriculture supply chain companies to ensure the sustainability of the food we eat and the water upon which it relies. In the U.S., irrigation accounts for more than 80 percent of total water consumptive use and up to 94 percent of consumption in regions most prone to water scarcity.” (The Nature Conservancy – Solutions to Address Water Scarcity in the US)
“America depends heavily on California. Its farms produce billions of dollars more each year than those in Texas, Nebraska and other states far more defined by agriculture. Water sustains jobs and livelihoods across the state’s economy, which outranks those of all but a handful of nations. Yet in no state does rainfall vary more each year, swinging between deluge and drought in a cycle that global warming is intensifying at both ends.” (New York Times – Who gets the Water in California?
“Agricultural is the largest consumer of the world’s freshwater resources, and the increasing demand for food will further intensify water usage in farming.” (Food and Agriculture Organization of the United Nations (FAO))
Activity 2: Ecological Pawprint Analysis
Purpose: Students will apply the ecosystem concepts they have learned to animals in their own lives.
Advance preparation:
Estimated time: 15 to 20 minutes
Place students in small groups, making sure each group includes at least one student who has one or more pets. Use the four agroecosystem questions to evaluate the ecological impact of their pets:
Where do key nutrients come from?
What does the pet eat? Where does the food come from? What happens to the pet’s waste?
What are the sources and sinks of pollutants in this system?
Does the pet cause pollution? What is the cumulative impact of dog and cat feces in this community? What about in different types of communities (urban, rural)? What is the recommended method of disposal of pet waste? What are the impacts of this method of disposal? What about pest management, medications, and grooming products for your pet? Do these products get into the environment?
How do the living organisms in the system interact?
How does the pet affect diversity? Does it hunt? Do escapees of its kind hunt or displace native species? How was it bred? Some exotic fish, reptiles, and birds that are caught in the wild and put into the exotic pet trade can put added pressure on rare species if let loose. In Florida, escaped Burmese Pythons have wreaked havoc on many native animal species in the everglades.
Videos on Ecological Pawprint:
How pets impact the environment
Optional: Florida Python Problem
What are the energy flows?
Does the pet require extra consumption of fossil fuel? (Think about producing, processing, and transporting its food, waste disposal, transportation costs for large animals such as horses, heating costs, etc.)
Have students discuss possible ways the ecology of pet management could be improved.
*Note that the Animal Protection Institute report on pet foods suggests that using processed slaughterhouse waste for pet food is a bad thing. However, from a nutrient cycling point of view, it is better than disposing of those wastes in a landfill and using premium meats to feed pets. Also, unprocessed meat would require refrigeration, using more fossil fuels.