|
The following activities are presented as ideas for focusing students on the global change issues presented in the chapter. Whether you decide to develop one, or many, of these activities, they should always be introduced by relating them to major themes contained within the chapter.
3.0 USING GRAPHS 2
Review the graphs provided on p.1 of Global Change and Canadians. Ask students to indicate when they think the first modern humans, Homo sapiens, appeared on the time sequences shown on the three graphs. Secondly, ask students to locate the time of the earliest appearance of urban-agricultural civilization on any of the three graphs. Lastly, ask the students to indicate the beginning of the Industrial Era or the Industrial Revolution on the graphs. What conclusions can be made from this activity? Specifically: Was it likely that early humans made a significant contribution to global change? Have students justify their views.
3.1 HUNTERS, GATHERERS AND FARMERS
When and where does current archaeological evidence suggest urban-agricultural civilization first made an appearance? What differences would there be in the environmental impacts of a hunter-gatherer lifestyle as opposed to an agricultural-fixed settlement one? What differences would there be between the quality of life of the two lifestyles? One group of students could study the lives of hunter-gatherers and a second group could study the life of early agricultural peoples such as those in ancient Sumeria, Babylon, or Egypt. The two research groups would then share their findings and the class as a whole would assess the environmental impacts of the two lifestyles.
3.2 HISTORICAL MACHINES
The invention of machines that use energy sources other than animal or human is often described as a "revolution"; an industrial revolution. A common misconception is that humans had no mechanization before the industrial era. The Egyptians, Greeks, Romans and other pre-industrial era peoples had many different machines. What is the major difference between these machines and those developed during the industrial era? Students might make models of some early machines and demonstrate how they were used, their benefits, and their possible environmental impacts.
3.3 THE IMPACT OF TECHNOLOGY
Technology has often been proclaimed as a boon to humankind and a path to a better world in the future. Ask students to do some research using source materials from the late 1940s or early 1950s and present some of the claims made about how nuclear power, electricity, the telephone, the helicopter, or other technologies would improve human life. Students should describe what the results of the technology have been and decide whether or not they resulted in an improvement in the conditions of life for most people.
3.4 EXPONENTIAL GROWTH
Ask students to take a single sheet of 8.5 x11" paper. Invite the students to predict how many times they think they could fold the sheet in half. Have each student record his/her prediction and keep it to themselves. Then begin the activity by folding the sheet in half once. Ask how much this fold reduced the surface area of the paper. Then ask the students to fold the reduced, folded sheet in half once again. Now how much has the area been reduced? Now fold the twice-folded sheet in half again. Continue to fold in half until it is no longer possible to fold the paper-usually around the seventh or eighth fold.
**********insert diagrams here********************
[Sidebar
Global Change and Canadians uses the example of duckweed, an aquatic plant which doubles its numbers every day under ideal growth conditions (p. 10). Students can begin exploring rates of change using the duckweed model. While the duckweed population may increase slowly at first, it reaches explosive rates relatively quickly. In nature, a delicate system of checks and balances keeps most life under these explosive rates of growth.]
Have the students look at their predictions of how many times they could fold the paper in half. How close did they come to what they experienced? It is easy to fold the paper the first few times. Why does it suddenly become impossible? Students might try to develop a graph to represent what is happening. If the fold number 1, 2, 3, etc., is plotted on the x axis of the graph and the surface area (neglecting the edges) is plotted on the y axis, what is the relationship?
3.5 EXPONENTIAL GROWTH 2
Another activity is to figure out compound interest curves. For example, let us suppose that students are asked to assume that they could save $10 every month and that they put it into an account on which the interest was paid on the monthly balance at a rate of 3% per year. How much money would they have in this account after 1 year, after 5 years, after 10, 20, or 30 years? Make a graph of the amount accumulated over time. Assume that they take no money out and that the interest rate never changes. Assume further that they always deposit $10 every month. Ask students to predict the amounts before they do the actual calculations. Electronic calculators and computer programs have simple steps for calculating interest and compounding it. Using a calculator may make the task easier and encourage students to try out different assumptions: for example, what would happen if they saved $5 per month, or $20 per month? What would happen if the bank calculated the interest at the end of each year, instead of at the end of each month?
Students should notice the shape of the curves in Activities 3.4 and 3.5. Exponential relationships may begin with gradual rates of change, but, after a time, as the changes compound, the curve begins to become steeper. Most projections of human population growth show continual increase in the near future with a gradual decline in the later 21st century. However, studies of animal populations have shown that there is often a population crash following periods of rapid, exponential growth because the population suddenly outstrips one or several of the critical environmental factors which limit population size.
In natural systems most populations do not fluctuate wildly. The numbers of most species tend to vary from season to season, year to year, around a mean or average size. Only if some environmental condition changes will the population show a sudden shift in size. Thus, deer populations will be limited by food, water, shelter, weather conditions, predators and disease. If there are severe winters the population may decrease for a time. If predators are hunted the population may increase for a while until checked by lack of food, disease, or by the return of predators. Ask students to list human population limiting factors.
3.6 BIRTH AND DEATH RATES
Global Change and Canadians illustrates the increase of human population in the developed versus developing countries (p.10). The projected increase in population in the developing world shows the shape of an exponential relationship. People often find this surprising when they hear that the percentage increase of global population varies between 1.5-4 %, rates which do not sound very large. Again, the interest rate examples are useful ways of helping people to understand that when interest is compounded a small rate can result in large gains over time. Of course, the compounding only has an impact if the deposits exceed the withdrawals. Students can be asked to explore the relationship between death rates and birth rates in the human population at this point in time.
3.7 HOW MANY IS A CANADIAN?
To illustrate the differences in environmental impact of one Canadian versus one citizen of Bangladesh, India, or China students might look at the relative consumption of resources and energy by persons in these countries.
Global Change and Canadians provides a graph of one of the differences, energy consumption, for selected countries. Thus, one Canadian consumes, per year, almost 9000 kg of oil equivalents compared to approximately 3500 consumed by a Saudi or 3000 by an Australian. If students were to decide that one Canadian was therefore equivalent in energy consumption to three Australians, the population of Canada in energy consumption terms would be three times its current actual size. Most of the countries on the graph are developed, industrialized nations.
What would be the difference if a Canadian was compared to a Kenyan, Somali, or Indian? Students might try to create a display showing the "real" population of Canada in terms of our use of other resources: water, copper, wood , paper, or food consumption. In order for students to explore resources that provide information about other nations as well as our own, the teacher and teacher-librarian should plan carefully.
Sidebar
Besides Global Change and Canadians, the UNDP Human Development Report is an excellent source for this information.
3.8 HOW MUCH ENERGY IS IN MY LUNCH?
To illustrate the ways in which our lifestyle depends on our use of energy students can construct some energy use flow charts for commonly used items in their lives.
Ask students to create a flow diagram for the energy demands of one item from their lunch, an article of clothing, a popular product such as a compact disc player or Walkman, or any other commonly used article. The activity is easier for simple items with fairly simple packaging, or no packaging.
For example, suppose a student ate an orange for lunch. How many energy-using steps were needed to get the orange from the tree in Florida to the student's lunch in the school cafeteria?
*********graph goes here***********
[sidebar
Each step requires energy, typically from electricity and/or fossil fuels. Is this diagram complete? What are some of the other energy- requiring actions needed to grow, pick, store, transport and market the orange?]
Each step requires energy. Even if each step is treated as requiring the same amount of energy, the total number of steps can be counted and compared to the number required for other common foods, i.e. orange juice in a tetrapak, a tuna fish sandwich, a hamburger at a fast food restaurant, a grilled cheese sandwich, lettuce for a salad.
3.9 ENVIRONMENTAL CONNECTIONS
Webs or chains such as the one in 3.8 can also incorporate the linkages between a product, the environment and the economy.
The flow chart for production of an orange can be turned into a web of environmental connections, with the orange at the centre of the web. The web can be made more complete by considering the jobs that people do which depend on or are in some way connected to growing, distributing and marketing the orange. Such activities can be useful ways of helping students develop a bigger picture of the connections among common products, the environment and the economy on a global basis. For example, are so-called "green products" really environmentally friendly? Are they friendly in terms of the distribution of wealth between the developed and developing worlds? For example, many developing countries have diverted efforts away from growing food for local consumption to producing food for consumption in wealthy countries, sometimes with negative effects on the local economies and the environment.
For example, coffee is a major cash crop in poor countries and is a major item of consumption in the developed world, but it is not grown in highly developed, industrialized countries. What impacts does the coffee trade have on the economies of poorer nations?
[Sidebar
An excellent source for information on connections is the State of the Earth Atlas and the Scientific American issue, Managing Planet Earth, September 1989. Also check with development NGOs in your area for information on this topic.]
3.10 THE WORLD IN A SUPERMARKET
To facilitate an understanding of the global connections of consumer goods, ask students to locate the sources of the components of food items found on the shelves of any local market. For example, in most parts of Canada it is possible to buy apples during any season of the year. Are these Canadian apples? If not, where did they come from? Most markets in Canada carry thousands of items of food. An exploration of market shelves and interviews with market managers will reveal where the various products come from. Use a large world map to make a display. Use the labels from some common foods, and use coloured thread and pins to connect the labels to the place associated with the production of the food item.
For a tin of tuna fish, the can may have been made from iron or aluminum ore from two different countries, it may have been manufactured from refined metals produced in a third, the label may have been printed in Taiwan, the printing presses may have been made in Japan, but the inks might have been made in Germany, while the tuna itself might have been caught off the coast of Africa by a Japanese trawler. If the tuna was packed in oil the oil may have come from the Mediterranean region while the tuna may have been processed in a Canadian fish packing plant. Where was the product actually "made"? The question takes on a different meaning looked at this way.
Here again, students can investigate the environmental consequences of this food product. The obvious connection may be to the fate of marine mammals such as dolphins and porpoises caught in the tuna nets and drowned. But less obvious connections are to be found in such issues as:
- the wastes from the steel mills or aluminum smelters
- the environmental impacts of the iron or bauxite mines
- the energy needed to smelt the metals
- the rate at which tuna, themselves an important part of ocean food chain, are being caught compared to estimated size of ocean tuna stocks
- the energy requirements to catch the fish using large vessels
- the numbers of jobs created in developed versus developing countries through the whole tuna fishing, processing, shipping and marketing business.
If people decide not to eat tuna because they are concerned about the fate of the dolphins, what other effects may this decision have? (See Appendix 1-Sample Lesson Plans for a more detailed description of this activity.)
******diagram goes here*******
3.11 WHERE DOES THE MONEY GO?
Students might select a single food item or other common item and do research on the economic importance of that item to the world economy or to the economies of the countries from which it comes.
- What sort of governments do these countries have?
- How many have strong environmental policies?
- What are their population sizes and what is the average annual income?
- When we purchase the product in our markets in Canadian dollars, how much of the money eventually finds its way to the "source" countries? How much of it gets to the person who grew the crop, or made the product?
It is often argued that one way in which the developed world assists the developing world is through the purchase of goods from them. But, this argument only has merit if a significant amount of the money actually finds its way to the people who do the work of production and processing in the source country. Global Change and Canadians identifies some of the common problems which afflict poorer countries apart from over-population. They include debt, unequal distribution of wealth, ineffective government, and military expenditures.
A way of treating this issue is to organize a class debate with the question being, "Resolved: there is no real global environmental crisis. The real problem is poverty in the lesser developed world." Such a debate would be a good way to synthesize the findings of research done to create flow charts or webs of connections as described above.
3.12 AIR AND WATER—ARE THEY FREE?
Global Change and Canadians suggests that commodities which are considered to be in infinite supply are often considered to be without market value, or to be valueless. As a consequence they are often treated in a very wasteful manner. Air and water are often thought of as being essentially free because they are apparently in limitless supply. Recently people have begun to discover how very limited the supply of good drinking water or clean air can be. There are several ways of exploring this topic.
Have students find out where water comes from in their community, using the following questions as a guide:
- What is the daily demand for water?
- How much water is available?
- Where do liquid wastes go and how are they treated before discharge?
- Does the city charge for water?
- What is the charge for domestic users, for commercial users, for industries?
- Is water use metered or is there a "flat rate" charge?
- What is the money collected as a water rate used for in the city's budget?
- Does the water rate cover the costs of sewage treatment, laying water lines, repairing and maintaining the water system? If not, why not?
After an analysis of the above questions, ask students to formulate a water policy that would encourage water conservation and enhance treatment of potential water pollutants.
3.13 CHANGING LIFESTYLE SURVEY
Have students interview members of their own families on whether or not they would be willing to make changes to the family lifestyle in order to reduce environmental impacts.
Create a survey to determine whether people would be willing to use alternate transportation, to recycle, to reduce power consumption, to conserve water, to reduce the purchase of packaged goods, or to avoid the use of products which are associated with environmental degradation. In order to reduce the possibility of embarrassment for the student or the family, the survey results should be submitted anonymously, and the results of all the surveys compiled and analyzed by groups of students. Decisions could be made collectively by the whole class as to whether or not Canadians see environmental problems as being significant enough to justify personal actions.
3.14 POSITION PAPERS
Students might work in groups to develop some position papers of human-environment interactions relating to the global change themes as discussed in Chapter 3. The papers should develop some real-world examples of a global change issue, and include both positive and negative aspects.
For each of the statements below, the group of students should construct an analysis of the evidence for or against the statement. In each case the team might also try to create an approach to the problem which is neither for or against but which approaches it in a conciliatory fashion. The class might use Chapters 3 and 4 to develop additional propositions similar to the examples given here.
- Is recycling good for the economy? If everyone in Canada reduced their use of paper products by a combination of reduce, recycle, reuse and refuse, the result would be the loss of hundreds of jobs in one of Canada's major industries: pulp and paper.
- Cost-benefit of newsprint recycling. Is it possible for recycling to result in more environmental impact than the production of new paper - after all, do papers not have to be de-inked, pulped, and bleached in the recycling process? All these processes use power, require chemicals, and generate waste products. Are there other reasons for recycling beyond the possible sales of recycled products?
- Water for sale. Canada has an abundance of water. We could fund many environmental clean-up efforts and other programs by selling our water to areas in the United States in need of water. What are the environmental and political costs of a water-selling policy in Canada?
- Effectiveness of boycotts and protests. Are protests and boycotts, such as those against logging in old growth forests, tuna fishing, drift netting and fur trapping, effective means for bringing about positive environmental changes? Do they penalize the targetted parties or is the burden often shifted to others?
- Population growth and international aid. The growth of our population is a serious problem. Unless we manage to control population growth in developing nations (and reduce resource consumption of the developed nations) global change consequences will be severe. Should Canada insist that a country adopt family planning and birth control policies before becoming eligible for aid programs?
|
