Classroom Idea: Ninth through Twelfth Grade

The World’s Deserts and Global Climate Change: How Will Humans Fare?

Introduction:

By studying the world’s arid regions, students can gain insight into a number of geographic themes, including the ways in which deserts (and other biomes) are depicted on maps, the ways in which people deal with inhospitable aspects of their environment and create technological solutions to natural obstacles, and the ways in which global climate change (global warming) may alter the world’s landscape and affect the lives of its people.

National Geography Standards:

• Standard 1: How to use maps and other geographic representations, tools, and technologies to acquire, process, and report information from a spatial perspective

• Standard 3: How to understand the spatial organization of people, places, and environments on Earth’s surface

• Standard 4: The physical and human characteristics of places

• Standard 7: The physical processes that shape the patterns of Earth’s surface

• Standard 8: The characteristics and spatial distribution of ecosystems on Earth’s surface

• Standard 9: The characteristics, distribution, and migration of human populations on Earth’s surface

• Standard 12: The processes, patterns, and functions of human settlement

• Standard 14: How human actions modify the physical environment

• Standard 15: How physical systems affect human systems

• Standard 18: How to apply geography to interpret the present and plan for the future

Procedure:

The World’s Deserts

1. Introduce the activity to the class by asking them to tell you where deserts are located. Do certain parts of the world have more or larger deserts than other places? Move on to a discussion of deserts. Is there much life in the desert? Ask them to give examples of the human presence in the desert. Some diverse answers might be the Bedouin of the Sahara or the cities of Phoenix and Las Vegas. Ask them to explain the ways that desert populations have coped with their harsh environments. Consider the types of technology that have helped cities grow in the southwestern United States: irrigation, dams, air-conditioning, and so forth. After they’ve come up with some answers, explain to the class that they’re going to learn more about the world’s deserts and will consider how global climate change might affect the arid regions and their inhabitants. Inform them that they’ll form groups to prepare a report entitled “Deserts: How Will Humans Fare?”

2. Discuss the concepts of global warming and global climate change. Are your students familiar with these issues? If not, explain that many members of the scientific community predict, based on evidence that they’re already seeing and on computer models that look into the future, that the world’s climate will become warmer in the future and that this climate change will have many effects around the globe. Tell the class that they’ll be reading about one of these climate models and seeing some maps showing how the world’s climate might change.

3. Divide the class into small groups.

4. Have each group examine the physical map. Ask them to look for the desert regions of the world. Tell them that although Antarctica is considered a desert, they’re going to concentrate on hot deserts.

5. As groups look at the map and the Web site, they should answer the questions on section one of the handout regarding the location and causes of deserts.

Global Climate Change

1. Have the groups take turns looking at three of the National Geographic inset maps on the world map:

   • Surface Temperature

   • Vegetation and Land Use

   • Population Density

   Ask students to consider how the desert regions are represented on each of these maps. How are surface temperature, land use, and population density related to desert conditions? Have them explain what they see on these maps in section two of the handout.

2. Ask groups to use the Internet to investigate some maps depicting global climate patterns. Have them go to Riddles of a Changing Climate at http://www.nationalgeographic.com/2000/physical/climate. They should read the introduction, click “Continue,” then select “Computer Model.” Then click “Climate Model Results.” After this page loads, students should read the introduction that describes the model that was used. Then ask them to look at the following sections and maps:

   3.0 “Surface air temperature warming” (Fig. 3)
   6.0 “Mid-latitude summer drying” (Fig. 8)

3. Have students analyze the maps in Fig. 3 and Fig. 8 and read the text for sections 3.0 and 6.0. They should answer the questions in section three of the handout to describe the changes that might occur in the world’s temperatures and aridity if CO₂ levels quadruple. Emphasize that, while there is strong evidence for global warming, what they will be reading about is just a model and should not be taken as fact or as something that will definitely occur.

The Future of Deserts

1. Now have the groups prepare reports entitled “Deserts: How Will Humans Fare?” They will need to use section four of the handout to help organize their thoughts. Their reports will discuss their assessment of how desert-dwelling people will respond to global climate change if it does in fact occur as the computer model they have seen predicts it will. They should think about people in desert and near-desert regions in different parts of the world and how different types of problems might arise depending on location. Ask them to visit the Web sites listed below to gather additional information for their report. These sites provide information on population growth in certain desert countries, special methods and technologies used to combat drought, and information about the political issues associated with water in the desert regions of the United States. Students should decide how to combine the information they’ve gathered throughout this lesson into a coherent, thoughtful report on the implications of global climate change for people in the world’s desert regions.

2. As an introduction to their assignment, you might want to go over the concept of population growth rate, as students will need to look at this statistic for several desert countries. Explain that the CIA World Factbook, which they will be viewing online, defines this rate as “the average annual percent change in the population, resulting from a surplus (or deficit) of births over deaths and the balance of migrants entering and leaving a country.”

Sites to investigate:

Cadillac Desert: Water and the Transformation of Nature:
http://www.kteh.org/cadillacdesert/home.html
(information taken from a documentary on the water issues and politics involved in the human development of the United States western deserts)

CIA World Factbook:
http://www.odci.gov/cia/publications/factbook
(information about the population growth rate of various desert countries)

National Drought Mitigation Center:
http://enso.unl.edu/ndmc

The Peace Corps: World Wise Schools: “The Desertification Debate”:
http://www.peacecorps.gov/wws/guides/senegal/debate.html
(links to sites with information on desertification)

Handout

(You can highlight this text and paste it into your word processor.)

SECTION ONE

a) Look at the National Geographic physical world map, and figure out which areas of the world are desert.

1. Which colors on the map represent desert?

2. Use the political map on the reverse side of the physical map to name one country containing a desert from each of the following continents: Asia, Africa, and South America. Also name one state from the United States that has a desert in it. List the countries and the state here or on your own piece of paper.

b) Go to the MGBnet Desert Biome Web page at
http://www.mobot.org/MBGnet/sets/desert/index.htm.
Find the information needed to answer the following questions:

1. Where do deserts tend to occur?

2. What natural phenomena cause deserts to form?

3. What are the three largest deserts in the world, and what continents are they on?

SECTION TWO

a) Look at three inset maps on the National Geographic map:

• Surface Temperature

• Vegetation and Land Use

• Population Density

b) Explain how deserts are depicted on these maps by answering these questions:

1. Are all desert areas in the hottest regions of the Earth?

2. What types of land (i.e., arable, forest., etc.) tend to be right next to desert regions? Why do you think these types of land tend to be next to deserts?

3. Do you see a relationship between desert regions and population? What is the population density of most desert regions?

SECTION THREE

a) Go to Riddles of a Changing Climate at
http://www.nationalgeographic.com/2000/physical/climate.
Select “Computer Model.” Then click “climate model results.” This report discusses the global climate change predicted by a computer model looking a hundred years into the future.

b) Find section 3.0 (“Surface air temperature warming”) and section 6.0 (“Mid-latitude summer drying”). Read these sections and look at the maps in Fig. 3 and Fig. 8.

c) Answer these questions:

1. According to this model, what will happen to the sea ice over the next hundred years?

2. According to this model, how will soil moisture change in the United States? In other parts of the world?

3. How will these changes in soil moisture, if they occur, affect agriculture around the world?

SECTION FOUR

You’re now going to prepare a report entitled “Deserts: How Will Humans Fare?” using the information you’ve already gathered plus additional information from some other Web sites. You’re going to consider how the predicted global climate changes might affect people living in desert regions of the world. You need to think about the situations faced by people in different desert regions. For example, people in Arizona will face very different issues from people in the Sahara. Your teacher will explain how the report should be organized. You’ll need to answer the following questions first and include these responses in the report. You should also include visual aids such as maps, charts, and pictures.

a) Go to the following Web sites for additional information to help you prepare your report:

• CIA World Factbook:
  http://www.odci.gov/cia/publications/factbook

  Look up the population growth rate for the desert countries that you listed in section 1b. Also look up the population growth rate of the United States, which is relatively low. How might a high rate of population growth affect populations in regions that could become increasingly dry and drought-prone in the future?

• The Peace Corps: World Wise Schools: “The Desertification Debate”: http://www.peacecorps.gov/wws/guides/senegal/debate.html

  Go to the section entitled “Web Sites About Desertification,” and follow some of these links.

  • National Drought Mitigation Center: http://enso.unl.edu/ndmc

  • Cadillac Desert: Water and the Transformation of Nature: http://www.kteh.org/cadillacdesert/home.html

• Where are deserts located throughout the world?

• How might desert populations in developing countries, such as African nations, be affected by global climate change?

• How might desert populations in the United States be affected by global climate change?

• Do you think that people are capable of creating enough new technology to overcome any obstacles that global climate change may bring to desert populations? What types of technology might be used or invented?

• Do you think that all desert populations will have access to new technology? Why or why not?

• Do you think that humans can overcome all obstacles related to global climate change and deserts, or do you think there’s a possibility that people will not be able to overcome all challenges? Why or why not?

Betsy Hedberg of Curriculum Adventures wrote classroom ideas and family activities for the National Geographic Society’s World Map Giveaway. The American Plastics Council, Kodak, State Farm Insurance, and Subaru of America sponsored the Map Giveaway.

For other great teaching resources, visit http://www.nationalgeographic.com/education.