1998 WWLPT Environmental Institute:  Precipitation

Global Warming Effects on Precipitation and Food Production
 

Avon Crawford  Stowe Elementary  Des Moines, Iowa

 
          Index for this page

• Instructor's Objectives
• Notes to Teachers
• Background
• Student labs
• Assessment
• Extension Ideas
• References

• The student will generate questions concerning global warming and future precipitation patterns that will affect food production.
• The student will be able to state an hypothesis, set up a lab, record data and analyze information based on the questions raised.

• Science students of grades 4-8

Notes to the Teacher:

The two labs presented here are for students who are learning how to generate an hypothesis and to run a lab. The students will be in groups of three or four. Half of the groups will work lab 1 and the other half will do lab 2. The results of these labs should generate other questions about precipitation and global warming as it relates to food production. The students will then formulate their own hypotheses and set up their own labs.
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Already there is evidence of increased storm activity. Storms are not only more frequent but more intense. Evidence of this includes:
 

•                                  The 1995 hurricane season in the Atlantic was one of the
•                                       most active on record.
•                                  Hurricane Andrew in 1992 left one quarter million people
•                                       homeless.
•                                          Years of draught in California contributed to a series of
•                                       devastating forest fires.
•                                 The 1993 floods in the Midwest caused an estimated
•                                       15.6 billion dollars in damage and claimed 38 lives.
•                                 In the last one hundred years, the frequency of extreme
•                                       precipitation events (more than two inches of rain in a
•                                       24 hour period) has increased 20%.

According to the Sierra Club more common and severe winter floods and summer droughts are expected.

Richard Wetherald of the Geophysical Fluid Dynamics Lab says that by 2035A.D. there will be a longer growing season for the North American continent. Canada will be able to be one of the major food producing countries because of this. During this period sections of the U.S. will be much drier especially the Midwest resulting in the decrease or non existence of food producing conditions.

Patricia Glick in "Global Warming: The High Cost of Inaction" agrees that extremes in temperature and precipitation will disrupt markets for food and other agriculture commodities with potentially devastating consequences.

According to the Meteorological Association global warming is expected to add to the difficulties of food production. Reduced availability of water resources would pose one of the greatest problems to agriculture and food production.

Based on this information the following labs will enable students to discover the changes in food production that will be necessary due to the change in precipitation patterns.
 
 
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LAB 1

Hypothesis

The frequency of water affects the growth and maturity rate of plants.
 

Supplies

purchased soil
5  pots of the same dimensions
bean seeds or seeds indigenous to a particular area
beaker that measures in ml
 

Procedure

1.  Plant bean seeds (2) in each of the 5 pots using the same amount of soil in each one.
     Label each pot.
2.  Set up a schedule to water each pot. Students create the schedule.
     i.e.:

                pot 1                pot 2                pot 3                pot 4              pot 5
            everyday         every 3 days     every 6 days     every 9 days    every 12 days

3.  Water each plant on the appropriate day with the same amount of water that has been selected by
     the student. i.e., 30ml
 
4. Record plant growth by measuring every day the length of the stalk and recording the number
    of new leaves.

5.  After four weeks analyze the data.
 

DISCUSSION QUESTIONS

         How will the increase or decrease in the frequency of precipitation as the result of
         global warming affect food production?

        What food crops would benefit either in an increase or decrease in frequency of
           precipitation?

        What other plants could this hypothesis be tested on?

        What other considerations are necessary for the growing of food?

        In your area of the country are the other effects of global warming such as higher
        temperatures or longer growing seasons pertinent to the crops raised?
 
 
 
 

LAB 2

Hypothesis

The amount of water affects the growth and maturity of plants.
 

Supplies

purchased soil
5  pots of the same dimensions
bean or pea seeds or seeds indigenous to a particular area
beaker that measures in ml
 
 

Procedures
 

1.  Plant bean seeds (2) in each of the 5 pots using the same amount of soil in each one.
     Label each pot.

2.  Set up a schedule to water the pots. Each pot should be watered on the same day(i.e., every three
     days) with varying amounts of water. Students should select the amount of water for each pot.
 

                pot 1                pot 2                pot 3                pot 4              pot 5
                10 ml               20 ml               30 ml                 40 ml              50 ml

3. Record plant growth by measuring every day the length of the stalk and recording the number of new
    leaves.

4.  After four weeks analyze the data.
 
 DISCUSSION QUESTIONS

         How will the increase or decrease in the amount of precipitation as the result of global warming
         affect food production?
 
        What food crops would benefit either in an increase or decrease in amount  of  precipitation?

        What other plants could this hypothesis be tested on?

        What the considerations are necessary for the growing of food?

        In your area of the country are the other effects of global warming such as higher temperatures
        or longer growing seasons pertinent to the crops raised?
 

The student will list questions that he/she has about global warming and food production that could be investigated further.

The student will design a lab based on his/her questions, set it up, record data and interpret it.

The student will be able to relate the three labs to the effects of precipitation change in global warming and how the production of food will be affected.

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 Laboratory Scoring Chart

Hypothesis stated clearly in complete sentences.                                            3 points
Hypothesis not clearly stated in complete sentences.                                       2 points
Hypothesis stated in incomplete sentences.                                                    1 point
Not stated                                                                                                   0 points

Data clearly organized with appropriate and correctly labeled graphs                 3 points
Data unorganized with correctly labeled graphs                                               2 points
Data unorganized with incorrectly labeled graphs                                            1 point
No data relevant to lab                                                                                 0 points

Conclusion relevant to data collected. Clearly stated in complete sentences.        3 points
Conclusion relevant to data collected, not clearly stated in complete sentences    2 points
Conclusion irrelevant to date collected                                                             1 point
No conclusion                                                                                                0 points
 
 
 

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