Lesson 3b: Climate Change and the Water Cycle

Transcription

1 Lesson 3b: Climate Change and the Water Cycle SUBJECTS Earth Science Physical Science OVERVIEW Climate change and human activities are affecting the way fresh water is distributed on Earth. In this lesson, students examine the effects of climate change on the water cycle and what this might mean for our planet. Students should have a general knowledge of the water cycle before beginning this lesson. GRADE LEVELS 4 8 CA SCIENCE STANDARDS Grade 5: Earth Sciences. 3. Water on Earth moves between the oceans and land through the processes of evaporation and condensation. (c, d) Grade 8: Periodic Table (Life Sciences). 7. The organization of the periodic table is based on the properties of the elements and reflects the structure of atoms. (b) ESSENTIAL PRINCIPLES OF CLIMATE LITERACY #6: Human activities are impacting the climate system. (C) #7: Climate change will have consequences for the Earth system and human lives. (A, B, C) ESSENTIAL QUESTIONS 1. How do human activities impact the water cycle? (Changes in climate alter the water cycle. Temperature plays a particularly important role, as increased heat speeds up the cycle. Over the past century, scientists have observed that temperatures have increased globally due to greenhouse gas emissions and that along with this, atmospheric water vapor has also increased. Warmer temperatures lead to increased rates of evaporation, transpiration, and the amount of water vapor in the air.) 2. How can climate change lead to drought, flooding, and other changes in precipitation? (A faster water cycle can lead to two seemingly contradictory results: increased drought and increased precipitation and flooding. In some environments, especially those with limited open water, increased evaporation and transpiration dries out the ground, leaving less water to move to the atmosphere, fewer clouds, and less precipitation. When precipitation does occur, it is more likely to be intense and heavy because the atmosphere contains more water.) 3. How can climate change lead to rising sea levels? (Sea levels rise with increased temperatures, not only because of melting glaciers and ice caps, but also because of thermal expansion. With more heat, water molecules move farther apart, increasing the volume of the ocean.) MEDIA RESOURCES QUEST video: Following Raindrops Video length: 8 minutes, 6 seconds Link: Through watching this video, students will learn: How the molecular structure of water changes as it moves through the water cycle About the effects of climate change on precipitation What human activities have to do with water redistribution on the planet Interactive animation: Climate Change and the Water Cycle Link: Through viewing this interactive animation, students will learn: How climate change influences the water cycle About the impact of global climate change on Earth s water resources 1

2 VOCABULARY drought a long period of abnormally low amounts of rainfall evaporation the conversion from a liquid to a gaseous state global warming an increase in the average temperature of Earth s atmosphere hydrology the scientific study of the properties, distribution, and effects of water on Earth s surface, in the soil and underlying rocks, and in the atmosphere isotope any two or more atoms of the same chemical element that have nearly identical chemical behavior but that have a different number of neutrons and different physical properties precipitation any form of water, such as rain, hail, or snow, that falls to Earth s surface watershed the region draining into a river, river system, or other body of water ACTIVITY 1: TRACKING RAINDROPS Time: minutes Materials: Computer with Internet access Projector with speakers Writing paper and pencils Procedure: 1. Review precipitation and the water cycle. How does the water cycle work? What happens to water as it goes through the water cycle? What isn t known about the water cycle? Make a class list of the things students think are still not understood about the water cycle. 2. Play the Following Raindrops video. 3. Discuss the following questions as a class: What are some of the questions the Keck Hydrowatch scientists are asking about the water cycle? (How old is the water? What role do plants and trees play in how water moves through the watershed? Where does the water come from? Was a storm cold or warm?) What happens to the structure of water as it moves through the water cycle? (Water changes its isotope value as it moves through the cycle.) What are scientists able to detect by studying these different water isotopes? (where the water comes from and how fast it moves through the watershed) How does studying these isotopes help scientists figure out how climate change could affect our planet and our water supply? (Knowing where water comes from and how fast it moves through watersheds allows scientists to create computer simulations of different weather scenarios. This information can be used to predict how global warming might change the climate and affect the supply of fresh water.) According to Inez Fung, what is one way climate change might affect our planet? (Where it is already hot, scientists predict that it will be hotter and drier and droughts are likely to occur.) 4. Assist students in identifying their watershed on a map. Ask students to think about their own watershed. Do you think we will experience drought or more precipitation in our area as the climate continues to change? Why? 5. Optional extension: Make a class poster with predictions. ACTIVITY 2: CLIMATE CHANGE AND THE WATER CYCLE Time: 45 minutes Materials: Computer with Internet access Projector and speakers or computer lab Drawing paper and pencils Handouts: three Student Worksheets Procedure: 1. If you have not conducted Lesson 3a, review the water cycle with students and have them watch only the water cycle portion of the interactive animation Climate Change and the Water Cycle. 2

3 WHAT CAN WE DO? How many glasses do you drink from in a day? Try using only one glass for your drinking water. Better yet, refill a designated nonplastic water bottle that you use every day. This will conserve water by cutting down on the amount of dishes that need to be washed at the end of the day! ACTIVITY 2 CONTINUED 2. Discuss what climate change may mean for our planet. How do you think precipitation will change throughout the world as a result of climate change? What areas do you think will experience drought? What areas do you think will experience flooding? What will happen to coastal communities as a result of rising sea levels? 3. Discuss what climate change may mean for our planet. How do you think precipitation will change throughout the world as a result of climate change? What areas do you think will experience drought? What areas do you think will experience flooding? What will happen to coastal communities as a result of rising sea levels? 4. Make copies of and hand out the three Student Worksheets. Divide students into partners to play a game using the interactive animation Climate Change and the Water Cycle. Before clicking through each of the three climate change scenarios, have partners draw what they predict will happen in each scenario. They should consider the following questions: What will happen to the lakes and rivers? What will happen to the oceans? What will happen to the ground and the soil? What will happen to the plants and animals? What will happen to the cities? 5. As they click through the scenes to see what happens in the animation for each scenario, partners should compare what they drew with what scientists predict might actually happen. 6. As a class, discuss some of the predictions students made for each scenario. Were their predictions close to the predictions of scientists? How did their predictions differ from what they observed in the animations? CLIMATE CAREERS Discussion Questions The video Following Raindrops includes information about many different types of scientists who are working on the Keck Hydrowatch project. What kinds of scientists are involved in the project? Make a list of the different types of scientists you remember from the video. Think about all these different types of scientists. What are their roles in the project? Could the project be completed if one of these roles was not filled? Why or why not? Think about the changes taking place on our planet. What important roles do you think these types of scientists will play in the future? Why will their jobs be important? 3

4 ABOUT THE AUTHOR Tamar Burris is a curriculum developer and former elementary school teacher. She is also a contributing writer to Kidsville News and other child and family publications. KQED Education Network engages with community and educational organizations to broaden and deepen the impact of KQED media to effect positive change. SUPPORT Funding for Clue into Climate: A Digital Media-Based Curriculum Unit on Climate Change was provided by the Corporation for Public Broadcasting. ASSESSMENT IDEAS In groups of three or four, students share what they remember about what the Keck Hydrowatch project hopes to learn and why this project is important. Students draw a picture and write a short paragraph about what will happen to an area in one of the following climate change scenarios: increased precipitation, drought, or rising sea levels. ADDITIONAL RESOURCES Anytime Lesson Plan: Earth s Water: A Drop in Your Cup, California Academy of Sciences (grades 2 8) In this lesson, students explore ways to conserve our finite fresh-water resources and brainstorm ideas for using untapped water supplies in their community. Drought, Earthlabs (adaptable for grades 5 12) This comprehensive unit on drought includes eight interactive lab lessons that teach students about such topics as the distribution and availability of the world s water, what watersheds are, the planet s normal climate patterns, what happens when precipitation patterns change, and drought mitigation trade-offs. (Note: All Earthlabs require Internet access, and most require a spreadsheet program like Excel and the free version of Google Earth.) Keck Hydrowatch Center, Keck Hydrowatch Center Visit the Keck Hydrowatch Center s website to learn more about the key goals of this project. Water Resources, U.S. Environmental Protection Agency (EPA) This section of the EPA s website about climate change provides information and data on the impact of climate change on our planet s water resources and on water resources in North America in particular on water availability, and on the quality of water throughout the world. Water Science for Schools, U.S. Geological Survey This website offers information on many aspects of water, including a guide to the amount of water on Earth, how it is distributed, and in what forms it exists. 4

5 STUDENT WORKSHEET PAGE 1 Climate Change Game Scenario 1: Increased Precipitation What will happen to lakes and rivers if there is more rain or snow? What will happen to the oceans if there is more rain or snow? What will happen to the ground and the soil if there is more rain or snow? What will happen to plants and animals if there is more rain or snow? What will happen to cities if there is more rain or snow? Your prediction What happens in the animation 5

6 STUDENT WORKSHEET PAGE 2 Climate Change Game Scenario 2: Decreased Precipitation What will happen to lakes and rivers if there is less rain or snow? What will happen to the oceans if there is less rain or snow? What will happen to the ground and the soil if there is less rain or snow? What will happen to plants and animals if there is less rain or snow? What will happen to cities if there is less rain or snow? Your prediction What happens in the animation 6

7 STUDENT WORKSHEET PAGE 3 Climate Change Game Scenario 3: Rising Sea Levels What will happen to lakes and rivers if sea levels rise? What will happen to the oceans if sea levels rise? What will happen to the ground and the soil if sea levels rise? What will happen to plants and animals if sea levels rise? What will happen to cities if sea levels rise? Your prediction What happens in the animation 7