Video and Transcript | List of Teacher's Guides

Curriculum Connections

Science/Environment Studies (Grade 7/8)

• Identify and explain the roles of producers, consumers, and decomposers of food in food chains and their effects on the environment;
• Investigate the use of technology on the environment.

Science/Environmental Studies (Grade 9/10)

• Investigate factors that affect ecological systems and the consequences of change in these factors.

Environmental Studies/Geography (Grade 11/12)

• Explain the flow of matter and energy through ecosystems;
• Explain how the earth is a self-sustaining system;
• Analyse ways in which selected human activities [e.g., agriculture] alter the natural environment;
• Identify differences in the perceptions of nature and the views on environmental preservation of selected individuals and groups;
• Evaluate government and industry strategies to promote sustainable management of resources;
• Research and report on technologies that improve the efficiency of resource use.

You Should Know...

The atmosphere is a complex mix of gases that trap the sun's heat near the Earth's surface. The main greenhouse gases in our atmosphere are water vapour (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3) and halocarbons (CFCs, HFCs, etc.). Without these greenhouse gases, the heat from the sun would escape and the temperature of the Earth would drop, making it too cold to support life.

Human activities - particularly the burning of fossil fuels - have increased the quantities of greenhouse gases released into the atmosphere. They remain in the atmosphere for long periods of time and intensify the natural greenhouse effect.

There are six greenhouse gases covered under the Kyoto Protocol, the international convention on climate change that has received a great amount of press coverage in the past few years:

• carbon dioxide
• methane
• nitrous oxide
• hydrofluorocarbons
• perfluorocarbons
• sulphur hexafluoride

Carbon dioxide (CO2) is a main contributor to climate change, especially through the burning of fossil fuel. Every tonne of carbon burned produces 3.7 tonnes of carbon dioxide. It is estimated that total global consumption of fossil fuels releases more than 20 billion tonnes of carbon dioxide into the Earth's atmosphere every year, increasing at about 0.5% per year.

This video examines the impact of cattle emissions related to the global methane budget and to the "big picture" of global warming. Ruminants produce 97% of methane generated in enteric fermentation by animals. Increasing cattle populations contribute to the amount of methane in the atmosphere. Methane is produced as a result of fermentation of carbohydrates in the ruminant digestive system. The gases from the fermentation of plant material in the first stomach are composed of approximately 65% carbon dioxide, 27% methane, 7% nitrogen and traces of other gases.

Methane is measured in a number of ways, but one estimate is that a typical cow may "belch" as much as 600 litres of methane in a single day. With nearly 1.3 billion cattle on earth, the amount emitted by cattle is enormous - somewhere in the neighbourhood of 300,000 billion litres every year - a number far larger than most of us can even imagine!

Although methane is less significant than carbon dioxide in the global warming picture, we cannot ignore the fact that cattle are highly concentrated in specific areas of the world, including specific areas in Canada. Projects are under way to produce feed for cattle that reduce their emissions.

Questions

1. How are most greenhouse gases produced?
2. How much of the world's methane is produced by cattle?
3. What is the average amount of methane produced by a cow in a year?
4. How is methane related to the concept of global warming?
5. How many stomachs does a cow have?
6. What is the main function of the first stomach (rumen)?
7. What 3 things work to break down the food that the cow eats to produce energy?
8. What are some of the results of the research related to the lowering of methane production in animals?
9. Fill in the chart below with the data from the video. Note that the total does NOT add up to 100%; there are other sources of methane, including landfill sites, which are not noted.

Reflection

1. What are the chemical components of the earth's atmosphere? Illustrate these components in graphic format.
2. The video suggests that, although there is less methane in the atmosphere than carbon dioxide, an increase in methane production will have a greater effect on climate change than an increase in carbon dioxide. Explain.
3. The video provides data on the INCREASE in carbon dioxide and methane. Illustrate this data in graphic form.
4. Often, suggested solutions for environmental problems have difficulties related to their applicability and economic feasibility. However, the results of the research being conducted by Agriculture and Agri-Food Canada are described as a "win-win-win" situation - good for the animals, good for the environment, and good for the "bottom line". Explain how the application of the research will be of benefit to all three "partners".
5. The emphasis in the video is on the feed components of the animals' diets. Research to determine other areas that are being investigated for the reduction of methane gas production by cattle, sheep and goats.
6. The increase in methane production by cattle is "fodder" for environmental groups that wish to promote vegetarianism. Explain.

Web Sites

www.agr.gc.ca/science
www.nrcan-rncan.gc.ca
http://www.epa.gov/methane/
www.nature.com/nsu/000907/000907-6.html
www.unfccc.int/

Assessment and Evaluation

Write a report to illustrate your understanding of the role of methane emissions in the larger picture of climate change and global warming.