Objective: Students will initiate a debate on the controversy surrounding the issue of inducing or enhancing precipitation.

Materials: None

Background: Explain to the students: Scientists have developed a way to make more and thicker clouds. They drop small particles into the air over an area that needs rain. Water that has evaporated from the ground but has not condensed onto anything yet, can then condense around these particles. New clouds and possible rain are formed over the region which otherwise would not have had any rain.

This works great for a farmer who needs rain. There is a problem however. The water that was made to rain onto the fields in one location, probably would have rained somewhere else at a later date. But since it rained over the field the airplane few over, there is not enough water in the air for it to rain over the fields it would have otherwise.

Procedure:
Debate the following scenario as a class: Sam has been farming his fields for 40 years. This year his fields have been the driest he has ever seen them. This is the worst drought he has ever seen. He has only had a few sprinkles of rain since he planted his crops two months ago. Sam worries about not getting any rain because if his crops die and he can't sell them at the market, he will have no money to buy food and clothes for his family. Also, his daughter has been very sick and in the hospital for the last two weeks. Sam thinks he may have to sell his tractors and some of his land to pay the hospital bills if he doesn't have any crops to sell.

Sam has heard about this new technique to make it rain over his fields. He wants to use this technique to help his crops grow. He has hired an airplane to fly over his fields and drop small particles in the air for the water to collect on and form clouds. He hopes that this new technique will make it rain more over his fields and make his crops grow.

Sally has been farming the fields next to Sam and has become good friends with Sam and his family. Sally has had more rain than Sam this year. Her crops could still use some rain but they are not nearly as bad as Sam's. Sally has heard of Sam's plans to hire an airplane to make more clouds and rain over his fields. Sally is worried that if Sam is successful with his plan to make it rain over his fields. Although Sally is very concerned for Sam and his family's problems because of the extreme drought, she is also concerned about maintaining the quality of her crops so that she can sell them at harvest time to the market.

Ask the class what they think about this. Should Sam use the airplane to try to make clouds and rain over his fields? Is this fair to Sally and her crops? Is Sam stealing rain from Sally? Is there any way that Sally and Sam can solve their problems while still remaining friends?

Extensions:
Have students research the method of the water cycle. As part of their research, have them "guess-timate" how many gallons of water travel from the ocean to your area. You will need to determine how close this guess needs to be. Have students obtain data from the library or Internet that will disclose what the precipitation in your area has been for a specific time period (ex. for the last 20 years). If possible, have them chart where the precipitation has mainly fallen and where it hasn't. Have them apply the above activity to the area where precipitation has mainly fallen and then discuss what that area would be like today, if cloud seeding had been available to do during their specific time period. How would the environment have changed? How would lifestyles have changed?

Develop a puppet show for younger kids based on weather modification. Brainstorm as a group ideas from getting more water for your crops, lawn, etc. and determine which ideas should be presented in the show. Divide the class into small groups and have each group take one of the ideas and design a set, or puppet or part of the script to illustrate their idea. Schedule a time to present your show.

Contact your state division of water resources, the state climatologist, or state engineer's office for additional information about cloud seeding activities, procedures and laws in your state.

Have the class complete the "Artificial Rain" activity from The Comprehensive Water Education Book, Grades K-6, from the International Office For Water Education. This activity will reinforce the effect of cloud seeding and weather modification.

Vocabulary Glossary:
Condensation: The process by which water changes from the vapor state into the liquid or solid state
Drought: A long period of time without rain
Precipitation: The process by which atmospheric water becomes surface water; the discharge of water, in liquid or solid state, out of the atmosphere


Activity adapted from: The Weather Unit
Grade Level:
3-6

Subject Areas:
Social Studies, Science, Reading

SD Standards for 4th grade:
Social Studies
4.C.2.1; 4.US.1.2; 4.E.1.2

Science
4.P.1.3; 4.L.2.1; 4.S.1.2; 4.S.1.1; 4.L.2.2; 4.E 1.1; 4.E.1.2

Reading
4.R.1.2; 4.R.2.1

Setting:
Classroom

Skills:
Inference, Communication, Interpretation

Prior Preparation: Students should have basic working knowledge of the water cycle. If you have Internet access, your class may want to visit "The Weather Unit" page for weather activities and information.

Vocabulary:
precipitation, drought, condensation
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