Lesson: Hey, You Stole My Rain!

Prerequisites:

The Water Cycle

Objectives:

Initiate a debate on the controversy surrounding the issue of inducing or enhancing precipitation.

Materials:

none

Introduction:

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. (remind the students of the tin can lid/salt experiment) New clouds and possibly 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 flew over, there is not enough water in the air for it to rain over the fields it would have otherwise.

Body:

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 an 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, that there will not be enough moisture in the air and clouds to provide rain for her fields. Although Sally is very concerned for Sam and his families 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. 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?

Conclusion:

none

Vocabulary Words:

drought

Evaluation:

none

Followup Lessons:

none