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  Effects of Global Warming On Human Health
 

 
Background Information: 

"DALLAS DECLARES EMERGENCY AS HEAT KILLS 16TH" 
These were the nation's headlines on July 15, 1998.  Earth's temperature is going up and so are the risks to human health.  How serious is it?  The 1995 United Nations Climate Change gathering of scientists concluded that it is already a serious problem.  The earth's average surface temperature has increased by 0.5 to 1.1oF. Computer-simulated models project an increase of 2 - 6oF by the year 2100. 

So how much damage can be done by a temperature increase of only 4.5oF, you ask?  During the last ice age global temperatures were only 5 - 9oF cooler than they are today.  That was enough to cover Canada, New York and New England under 3 feet of ice!  Small changes in temperature can produce major changes in climate. 

Changes in climate patterns bring about changes in disease patterns.  Warmer temperatures and wetter climates enhance the breeding conditions for organisms that transmit disease.  Warmer and wetter climate (1961-1990) in Rwanda has increased the incidence and geographic range of Malaria.  In northwest Pakistan a regional temperature increase of 
0.5oC (32.9 o F) has contributed to the transmission of same disease.  Cases have risen from a few hundred in 1980 to 25,000 in 1990. 

Redistribution of other diseases like yellow fever and dengue fever are now evident at higher altitudes and latitudes, as seen in India and Columbia in South America. 

Other ways in which global warming threatens human health: 

 *  temperature extremes 
  -  heat wave in Chicago, July 1995--700 deaths 
 *  injuries from storms, coastal flooding 
  -  interruption of power supply, contamination of drinking water 
 *  drought 
  -  food shortages due to shift in agricultural food production 
 *  air pollution ( made worse by warming) 
  -  asthma, bronchitis, emphysema complications 
 *  strain on public health systems 
  - increased need due to population migrations 
  - unable to contain spread of infectious diseases 

So which segments of the human populations would be most affected?  Obviously, those with the least resources.  Developing countries with inadequate access to health care will suffer disproportionately.  Those lacking economic resources 
to adapt agricultural to climate changes will suffer hunger and famine. 

Developed countries are not immune.  In this country, the poor, sick, old and young will suffer most.  People with heart problems are most affected during heat waves.  Elderly with lung disease and young with asthma will suffer more with the increase of Ozone at ground level.  A 4 F degrees increase in global temperature will increase Ozone at low levels by 5%. 

Human health effects of global warming are many and varied.  For purposes of this lesson we will focus only on those that affect humans.  Knowing of course, that our connection with all other living things does not allow us to look upon these effects in isolation.  What affects one segment of the living world affects all others directly or indirectly. 
OBJECTIVES: PRE-LAB ACTIVITY:
Using On-line resources, students will gather information as to how global warming will affect human health.  Students will use the following questions as a guide for conducting their research:

a. How will global warming affect human health?
b. How much of a temperature change is necessary to impact human health?
c. Which segments of the world's human population will be most affected?
 

 
LAB INVESTIGATION:
Effects of Temperature on the Development of Mosquito Larvae

Lesson Description: This study investigates the effect of water temperature on the development of mosquito larvae. Students will observe mosquito larvae under three different temperature environments. 
 

Objective:       Students will study the effect of environmental temperature on the rate of mosquito pupation.
Unit Length:    one week

Time:              One 45 period to begin the study and do a set up
                        One 45 minute period for cleanup and closure
                        10 minute per day time intervals for observations and recording of data.
                        Entire study should take 2 weeks or until all pupa have completed metamorphosis.

Grade Level:  Grades 7 - 12. Adaptable for younger students.
 
Materials:      30 mosquito larvae (pupa)
                        3 clear containers that have the same shape and capacity
                        mosquito netting (cheese cloth may be used)
                        supply of  distilled water
                        elastic bands to secure netting across the top of each container
                        thermometers
Procedure:

    1. Propose  a working hypothesis concerning the development of mosquito pupae into adult mosquitos in high and low temperatures.
    2. Obtain  3 similar water containers, 3 elastic rubber bands to secure the netting, and distilled water
    3. Label containers as follows: one for cool temperature, one for room temperature and one for elevated temperature.
    4. Fill each container with distilled water to the half full mark
    5. Place ten mosquito pupae in each container and place in the appropriate environment.
    6. Each day record the number of pupae that have metamorphosed into mosquitos.
    7. At the end of the study, dispose of the materials as per teacher's instructions.
Results:
    1. Arrange data into table showing dates, water temperature, number of mosquitoes becoming adults, and percentage of adult mosquitoes.
    2. Plot a line graph showing all data from day one to end of study.
Analysis and Interpretation:
    Write a conclusion that includes the following:
      Which test group is the control group? Why?
      How did your results compare to those of others in the class?
      Evaluate your original hypothesis based on your collected data.
      What connections can you make concerning global warming and the distribution of insect vectors?
     
Suggestions for extension:
    1. Propose a new hypothesis and design a controlled experiment to test that new hypothesis.
    2. Research a mosquito borne disease and present your findings to the class.
    3. Write a narrative from the point of view of a mosquito, "A Day in the Life of a  Mosquito."
    4. Research the "tiger mosquito" and why its appearance is considered significant for the U.S..
    5. Discuss/debate how a global climate change might affect the health of someone from a developed country vs. someone from a developing country.
Assessment:
    Use the following links to help you develop innovative alternative forms of assessment.

              Concept mapping links:
               1) Lesson in teaching concept maps to students-visual included
               2) More in depth example of a concept map - detailed visual included
               3) Teacher instructions and tips

                Rubrics:
               1)  Teacher Links On Rubrics
               2) Rubric Information - Advanced Secondary

Bibliography:

         ENVIRONMENTAL SCIENCE, Cunningham, Saigo; WCB McGraw-Hill

         NUCLEUS, Magazine of Union of Concerned Scientists, "The Road to Ruin," Goetz, D.,
            Vol. 19, # 2, Summer '97
 
         GLOBAL WARMING- HUMAN HEALTH, Regional Impacts-North America,
            U.S. Env. Protection Agency, Ch. 8
       
         NATIONAL CENTER FOR PUBLIC POLICY RESEARCH, "Larger public health risks overlooked in
            the global warming debate, respected science organization says," Nov. 1997.
 
Additional Sources:

 
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