Comprehensive Sample of ESS Protocol
First, you will do an Earth system science analysis. Then, you will make predictions, based on the results of the ESS analysis, concerning the growth of hard-red winter wheat in Kansas 50 years in the future.

Following the steps below will help you to accomplish your tasks.

Step 1 List what is known. 
Step 2 List what is needed.
Step 3 Gather information to complete an ESS analysis. ( Event to Sphere, Sphere to Sphere)
Step 4 Present your findings.

Step 1: List What Is Known
The two columns below illustrate the parallel jobs to be completed in Step 1. You do not need to conduct any research to do this step. Use your current knowledge and information from the scenario to fill in the lines provided.

In the space provided in the first column, list what you know about hard-red winter wheat. Then look at the Earth System Diagram in the second column. Notice how the arrows go to and from the event and spheres. These arrows indicate that the cause and effect relationships go both from the event to the spheres and from the spheres to the event . While thinking about these relationships, list your ideas about how the event--increased concentrations of atmospheric carbon dioxide--could possibly impact the four spheres that make up the Kansas wheat farm ecosystem.

List prior knowledge about hard-red winter wheat.

• Hard-red winter wheat is grown in Kansas.
• Hard-red winter wheat is planted in the fall and lies dormant through the winter.
• Hard-red winter wheat is harvested in the spring.
• Changes in temperature and precipitation may result in significant declines in the yield of hard-red winter wheat.
• Hard-red winter wheat is a plant that requires carbon dioxide (CO₂) to conduct photosynthesis; this means it needs CO₂ to produce sugar and grow. Increased concentrations of CO₂ may increase growth of hard-red winter wheat.
• There are many varieties of wheat that are developed to grow in many different conditions.

List prior knowledge of Earth system science regarding increased concentrations of atmospheric carbon dioxide.

Increased Carbon Dioxide Event  Biosphere

• Plants require carbon dioxide in order to photosynthesize and grow. An increase in carbon dioxide may result in an increase in photosynthesis and thus an increase in plant growth/yield. This has been observed in scientific experiments.
• When plants photosynthesize, they accumulate carbon from the carbon dioxide in their tissues. This carbon is stored in the form of sugar and other organic molecules. In this way, plants act as carbon sinks or storage areas. When a forest is clear-cut, the carbon sink is gone. There will be nothing in that area to take up and store atmospheric carbon dioxide. The result will be an increase in atmospheric concentrations of the gas.
• When plants decompose, respire, or burn, they release stored carbon to the atmosphere in the form of carbon dioxide. The chemical reaction for each of these processes is the opposite of photosynthesis. When trees are burned to clear land for farming, they release carbon dioxide and increase the atmospheric concentration of this gas.

Increased Carbon Dioxide Event  Lithosphere

• The lithosphere is a carbon sink. It reacts with the atmosphere and stores carbon. If atmospheric concentrations of carbon dioxide increase, then concentrations of carbon in the soil (lithosphere) may increase.

Increased Carbon Dioxide Event  Atmosphere

• Carbon dioxide is a greenhouse gas. Greenhouse gases absorb some of the long-wave radiation emitted from Earth's surface. When they become energized from this radiation, molecules of greenhouse gases emit heat in all directions--including back toward Earth. If atmospheric concentrations of carbon dioxide increase, then Earth's temperature may increase.

Increased Carbon Dioxide Event  Hydrosphere

• Earth's waterways--especially oceans-- are carbon sinks. They react with the atmosphere and store carbon. If atmospheric concentrations of carbon dioxide increase, then concentrations of carbon in Earth's waterways may increase. Historical data in textbooks supports the correlation between atmospheric and oceanic carbon.
• Temperature controls the circulation of water through the hydrosphere. If increases in atmospheric concentrations of carbon dioxide cause Earth's temperature to increase, then there will be changes in the rates and distribution of evaporation, condensation and precipitation.

Step 2:  List What Is Needed. 
Now that you have an idea of what you DO know about hard-red winter wheat and the impacts of the event on the spheres and the spheres on the event, you need to think about what you DO NOT know. Below, you will ask questions that will guide the research that may take place on the Internet, in the library, or with other sources. 

In the first column, list your questions about hard-red winter wheat. Ask questions in the second column to direct the research you will conduct in Step 3. These questions should help you to focus your research on finding information to complete the ESS analysis of the impacts that increased concentrations of atmospheric carbon dioxide could have on the four spheres that make up the Kansas wheat farm ecosystem.

List your questions regarding hard-red winter wheat.

• Other than Kansas, where is hard-red winter wheat grown?
• Is hard-red winter wheat an important crop?
• At what temperature does hard-red winter wheat germinate?
• Do hard-red winter wheat seeds need to freeze before they can germinate?
• At what temperature does hard-red winter wheat produce the best yield?
• Is there a maximum temperature at which hard-red winter wheat will grow without suffering yield loss?
• How much water does hard-red winter wheat require?
• How much water is too much for hard-red winter wheat?
• Will increased concentrations of carbon dioxide directly result in increases in hard-red winter wheat yield by increasing rates of photosynthesis?

List your questions regarding the impacts that increased concentrations of atmospheric carbon dioxide could have on the four spheres that make up the Kansas wheat farm ecosystem.

• What was the atmospheric concentration of carbon dioxide before it started to increase?
• What is the current atmospheric concentration of carbon dioxide?
• What would produce increased concentrations of carbon dioxide in the atmosphere?
• Is it possible to reverse the trend of increasing atmospheric concentrations of carbon dioxide?
• By how much--if any--will atmospheric concentrations of carbon dioxide increase in the next 50 years?
• Will increased concentrations of atmospheric carbon dioxide increase rates of photosynthesis in plants--namely hard-red winter wheat?
• How does carbon dioxide react in the soil?
• How does carbon dioxide affect soil pH?
• How does soil pH affect the uptake of nutrients by plants?
• How much will temperature increase as a result of increased concentrations of atmospheric carbon dioxide?
• How will increased concentrations of atmospheric carbon dioxide affect precipitation?
• Will increased concentrations of atmospheric carbon dioxide have other affects on the weather?

Step 3: Gather information to complete an ESS analysis.

Part I: Using the answers from your research, list any additional cause and effect relationships you found for the event and the spheres. These relationships should build on or be different from the ones you listed in Step 1. The answers you find should explain the possible causes and effects increased concentrations of atmospheric carbon dioxide could have on the spheres that comprise the Kansas wheat farm ecosystem. Keep track of where you locate information. You may need to look it up again when you do Step 4.

Increased Carbon Dioxide Event  Biosphere

• Carbon dioxide is produced when people burn fossil fuels such as coal and oil. Human activities have resulted in increased atmospheric concentrations of carbon dioxide. Evidence of this is the change in the atmospheric concentration of carbon dioxide since humans became industrialized. Before the Industrial Revolution in the early 18^th century, atmospheric concentrations of carbon dioxide were about 275 ppm. By 1999, atmospheric concentrations of carbon dioxide increased by 85 ppm to reach 360 ppm. Human population and economic growth rate are directly related to the amount of carbon dioxide produced. As population or industrial activity increases, so does the need for fuel. Nuclear energy may be an alternative energy source, but it is currently more expensive to use. If the human population and economic growth rates, as well as nuclear energy costs, do not change significantly in the future, then atmospheric concentrations of carbon dioxide will reach 700 ppm by the year 2100. If the human population increases, economy grows, and nuclear energy costs rise, then atmospheric concentrations of carbon dioxide could reach as high as 900 ppm by then. It will take a very long time to reverse this trend of increasing atmospheric concentrations of carbon dioxide. Even if the emissions of carbon dioxide during the next 100 years are lower than they are today, the actual atmospheric concentration of carbon dioxide may increase by as much as 90 ppm.
• Increased concentrations of atmospheric carbon dioxide lead to increased rates of photosynthesis in C₃ plans like hard-red winter wheat. Scientific research supports this. An increase in photosynthesis would result in increased crop yield.
• Increased concentrations of atmospheric carbon dioxide cause plants like hard-red winter wheat to close their stomates, the holes in their leaves through which they take up carbon dioxide and lose water. This allows the plants to take up large amounts of carbon dioxide while losing less water. The result is increased water-use efficiency--the ratio of plant biomass to the amount of water consumed.
• The results of scientific studies show that increased concentrations of atmospheric carbon dioxide lead to increased yields of hard-red winter wheat even in otherwise less than ideal conditions such as increased temperatures or decreased water availability. This is because the positive effects of increased concentrations of atmospheric carbon dioxide on yield is greater than the negative effects of too much heat or too little water.

Increased Carbon Dioxide Event  Lithosphere

• Atmospheric carbon dioxide trapped in moist soil reacts with the soil water to form carbonic acid, H₂CO₃. The chemical equation for this reaction is H₂O + CO₂ H⁺ + HCO₃^- H₂CO₃. This process decreases the pH of the soil, making it more acidic.

Increased Carbon Dioxide Event  Atmosphere

• Once carbon dioxide is emitted to the atmosphere, it stays there for a long time.
• Historical data shows a direct relationship between atmospheric concentrations of carbon dioxide and mean global temperature. As atmospheric concentrations of carbon dioxide increase (or decrease), so does mean global temperature.
• It is predicted that increased concentrations of atmospheric carbon dioxide will cause mean global temperatures to increase by 3.5 ºF (1.9 ºC) over the next 100 years.
• According to climate models, temperatures in Kansas in the year 2100 could be 2°F (1.1 ºC) greater in spring, 3 °F (1.7 ºC) greater in the summer, and 4 °F (2.2 ºC) greater in fall and winter than they are now.

Increased Carbon Dioxide Event  Hydrosphere

• Precipitation events can wash carbon dioxide out of the atmosphere.
• Rivers, streams, groundwater and especially oceans are carbon sinks. Carbon dioxide is dissolved from the atmosphere into these waterways.
• Scientific studies have revealed that the residence time of carbon dioxide in the surface ocean is approximately 6 years.

Part II: Using the answers from your research, list the cause and effect relationships that occur between and among the spheres. Note: Begin thinking about how these relationships may in turn affect future yields of hard-red winter wheat.

Atmosphere  Biosphere

• Increased amount of soil particles in the air (see Atmosphere  Lithosphere) could coat the lungs of animals and decrease their ability to breathe.
• Increased amount of soil particles in the air (see Atmosphere  Lithosphere) could coat the leaves of plants and decrease their ability to absorb sunlight and CO₂, therefore their ability top photosynthesize and grow will be hindered.
• Wheat germinates best in areas with temperatures between 68 ºF (20 ºC) and 77 ºF (25 ºC). Winter wheat requires a cold period of 6 to 8 weeks at temperatures between 32 ºF (0 ºC) and 52 ºF (11.1 ºC) before it will produce flowers and mature. If the temperature is too high (or too low), wheat may not germinate and grow properly. The result will be a decrease in yield.
• High temperatures cause reduced rates of photosynthesis. This can lead to a decrease in wheat yield.
• High temperatures can increase the occurrence of bacterial disease in living organisms, including crops. At high temperatures, bacteria multiply and spread more. This is why scientists keep bacterial cultures in incubators to increase the growth of their specimen. Crops with bacterial infections produce a lower yield.
• High temperatures can increase the occurrence of fungal growth. We place food in the refrigerator--at a cold temperature--to prevent fungal growth. If we leave food out in the warm air, it will quickly become moldy (covered with a fungus). Crops with fungal infections produce a lower yield.
• High temperatures can increase the occurrence of insect infestation. A large portion of the insect population dies during the winter months as a result of cold temperatures. If winter temperatures are mild, many of these insects will survive the winter. These insects will then infest crop fields and eat the crops. This can decrease crop yield.
• High temperatures can increase the rate of decomposition of organic matter by increasing the metabolic rate of soil microbes. This means the soil microbes need to decompose organic matter at a faster rate to obtain energy at a faster rate.

Atmosphere  Lithosphere

• High temperatures can cause soils to dry out and turn areas into deserts like the Mojave and Sahara.
• Dry soil (see Atmosphere  Hydrosphere) is light and is easily carried into the air by wind. Evidence of this is the "Dust Bowl" in the U.S. southern plains states during the 1930's. During this time, farmers over worked land that had become dry and barren as a result of severe droughts. The dry soil was so loose that it was often carried into the wind in large dust storms.

Atmosphere  Hydrosphere

• Carbon dioxide and water react with each other in the atmosphere to form carbonic acid, H₂CO₃. The chemical equation for this reaction is H₂O + CO₂ H⁺ + HCO₃^- H₂CO₃. This process decreases the pH of precipitation, making it more acidic.
• Increased rates of evaporation will result in increased concentrations of water vapor in the atmosphere. This water vapor is carried by the wind and eventually cools. The cooled water vapor forms clouds and leads to precipitation in another area. In this way, temperature controls the water cycle.
• Increased temperatures will lead to increased rates of evaporation of water from soil and plants. The water will become hot and transform into a vapor more quickly. This can be seen when a teakettle is placed on the stove. If the burner temperature is on low, then it takes a long time for the water to boil and eventually begin to evaporate. If the burner temperature is on high, then the water begins to boil and evaporate more quickly.
• Increased temperatures result in an increase in the amount of energy and pressure in the atmosphere. The result is increased storm activity that can lead to large amounts of precipitation falling over relatively short time periods.
• Soil particles in the air act as condensation beads upon which water condenses and clouds form. An increase in the condensation beads in the atmosphere results in more clouds and thus more precipitation.
• Clouds--collections of water droplets--reflect the sun's light back into space. Increased cloud formation causes increased reflection of light to space. With less sunlight reaching Earth's surface, the planet's atmospheric temperature decreases.
• Soil particles reflect the sun's light back into space. Increased amounts of soil particles in the air causes increased reflection of light to space. With less sunlight reaching Earth's surface, the planet's atmospheric temperature decreases.
• Carbon dioxide is more soluble in cold, salty water like that in the deep ocean. As atmospheric temperatures decrease, so do the temperatures at the ocean's surface. A decrease in atmospheric temperature may lead to an increase in carbon dioxide dissolved in the ocean. An increase in carbon dioxide dissolved in the ocean means there is less carbon dioxide in the atmosphere. Therefore atmospheric temperatures will not be elevated as much by the greenhouse effect. Earth's temperature may further decrease. This is a positive feedback loop.
• The ocean, as well as sea ice and polar ice caps absorb heat from the atmosphere. If Earth's temperature rises, then the polar ice caps may melt. This would result in more liquid water flowing into the oceans and thus a greater sea level.
• Polar ice caps reflect solar energy to space. If polar ice caps melt due to elevated temperatures, then there will be more bare ground to absorb solar energy. The result would be further warming of Earth's atmosphere. This is a positive feedback loop.
• The temperature of the ocean affects the strength and pattern of wind through the atmosphere. An example of this is the El Niño event.
• As the temperature of water increases, the ability of oxygen to dissolve in it decreases. Therefore, warm water has low dissolved oxygen content.

Biosphere  Hydrosphere

• Warm water has a lower concentration of oxygen (see Atmosphere  Hydrosphere). This may lead to the suffocation of aquatic organisms such as fish.
• Too much precipitation could result in flooding and the drowning of plants and animals.
• Too much evaporation, coupled with too little available water, can lead to wilting and ultimately the death of plants.
• Increased sediments in stream water (see Hydrosphere Lithosphere) can decrease the amount of sunlight reaching aquatic plants.
• Farmers cannot harvest wheat if it is too wet because it will clog their machines .
• Farmers cannot harvest wheat if the field is wet--even if the crop is dry--because the machines will get stuck in the mud.
• Too much water can increase the occurrence of bacterial disease and fungal growth, both of which can decrease crop yield.

Biosphere Lithosphere

• Plants suffocate in waterlogged soil because there is not enough available oxygen.
• Decreased soil moisture would mean less water available to plants. They would shrivel up and die.
• Decaying plants and animals return nutrients to the lithosphere.
• Soil pH affects the way many nutrients are absorbed by plants.

Hydrosphere  Lithosphere

• Carbonic acid, H₂CO₃, in soil solution breaks down silicate rocks through the process of carbonation weathering.

• Water holds soil together. A lack of water in the soil makes it lighter and more easily eroded by the wind.
• Large, rapid inputs of water such as from heavy downpours can wash away soil.
• Increased erosion can lead to increased soil particles (sediment) in stream water.
• Increased sea level (see Atmosphere  Hydrosphere) can lead to flooding of coastal communities.

Step 4: Present your findings
Prepare a report or presentation of your firm's predictions about future yields of hard-red winter wheat based on your ESS analysis.

Predictions based on ESS Analysis:
The results of recent studies reveal that atmospheric concentrations of carbon dioxide (CO₂) may be increasing. Predictions of increased atmospheric concentrations of CO₂ concern Jim Anderson and his wife. They wish to establish a farm in Kansas and grow hard-red winter wheat. This is the major class of wheat grown in Kansas. It is also the class of wheat most exported from the United States. Mr. and Mrs. Anderson wish to establish a wheat farm that will be productive well into the future for the sake of their children. They are worried that increased atmospheric concentrations of CO₂ may decrease the yield of hard-red winter wheat in Kansas in 50 years.

Because of their concern, the Andersons came to our firm, Earth System Science Environmental Research (ESSER). They asked us about future yields of hard-red winter wheat in Kansas. We performed an Earth system science (ESS) analysis on the impacts of increased atmospheric concentrations of carbon dioxide on Earth's spheres. From this analysis we prepared the following report on the impacts of the event on of the Kansas wheat farm ecosystem.

We found the atmospheric concentration of carbon dioxide (CO₂) has been increasing in recent decades. Atmospheric CO₂ has many natural sources. However, a major source of increased atmospheric concentrations of this gas is human activities. These activities include the combustion of wood, coal, and oil for energy. People have been using wood as an energy source since the discovery of fire. The use of coal and oil became more widespread in the early 18^th century. The widespread use of these fossil fuels was a result of the Industrial Revolution. The Industrial Revolution was the period when a lot of new power-driven machinery was invented.

The atmospheric concentration of CO₂ has been increasing since the Industrial Revolution. Before the early 18^th century, atmospheric concentrations of CO₂ were about 275 ppm. By 1999, atmospheric concentrations of CO₂ increased to 360 ppm. If current rates of CO₂ production continue, then atmospheric concentrations of CO₂ will reach 700 ppm by the year 2100. If human activities lead to increased rates of CO₂ production, then atmospheric concentrations of CO₂ could reach as high as 900 ppm by then. It will take a very long time to reverse this trend of increasing atmospheric concentrations of CO₂. Even if the emissions of CO₂ in the next 100 years are lower than they are today, the atmospheric concentration of the gas may become as much as 90 ppm higher than the current concentration. This is because CO₂ stays in the atmosphere long after it is emitted.

The atmospheric concentration of CO₂ is very important. Carbon dioxide is a greenhouse gas. Greenhouse gases absorb long-wave radiation that is radiated from Earth's surface. When molecules of greenhouse gases become energized, they emit heat energy in all directions. By emitting heat energy toward Earth, greenhouse gases cause the planet to heat up. This process is called the greenhouse effect. The greenhouse effect keeps Earth from becoming too cold. However, if the atmospheric concentration of greenhouse gases like CO₂ become too high, then Earth's atmosphere may become too warm.

Scientific evidence shows that changes in Earth's temperature are directly related to the atmospheric concentration of CO₂. Atmospheric concentrations of CO₂ have been increasing in the last century. So has Earth's mean global temperature. It is estimated that Earth's mean global temperature has increased by 0.5 to 1.0 ºF (0.3 to 0.6 ºC) in the last 100 years. If current emission rates of CO₂ continue, the mean global temperature may increase by 3.5 ºF (1.9 ºC) over the next 100 years.

The temperature of Earth's atmosphere controls the cycling of water through the planet's hydrosphere. Elevated temperatures speed up the water cycle. As temperature increases, so does the rate of evaporation. This causes the lithosphere to become dry. When the lithosphere becomes dry, it can no longer provide water to plants (E > A > H > L > B). In addition, high temperatures cause increased evaporation of water from plants and other members of the biosphere (E > A > H > B). Therefore, high temperatures can decrease the amount of water available to plants and at the same time increase the amount of water plants loose. These changes can severely decrease the yield of crop plants.

High temperatures can also increase fungal and insect infestations (E > A > B). Both of these can destroy crops and cause decreased crop yields, too. On the other hand, high temperatures can increase the rate of decomposition of organic matter by soil microbes. Increased rates of decomposition result in increased availability of nutrients that plants require for growth (E > A > B > L > B). This can increase crop yield.

While elevated temperatures cause rates of evaporation to increase, they also cause precipitation to increase. However, the precipitation usually occurs far away from the point of evaporation. Therefore while one area may become very dry, another area may become very wet. If current emission rates of CO₂ continue, mean global precipitation over the next 100 years will increase. Because of the high temperatures, there will be a lot of energy in Earth's atmosphere. This will cause the precipitation to fall during several short, intense storms. Such storms can lead to flooding of the lithosphere and drowning of members of the biosphere. Fields of crops can be destroyed during storms and floods (E > A > H > B).

Like the short-term weather events such storms, the long-term weather pattern, or climate, of a region has a great impact on crop yield. Each type of crop requires a certain climate in order to germinate and grow. Crops like rice require a warm, moist climate. Wheat, however, requires a cooler, slightly drier climate. Wheat germinates best in areas with temperatures between 68 ºF (20 ºC) and 77 ºF (25 ºC). Winter wheat requires a cold period of 6 to 8 weeks at temperatures between 32 ºF (0 ºC) and 52 ºF (11.1 ºC) before it will produce flowers and mature. Winter wheat will not germinate and grow if the climate is too warm.

Atmospheric concentrations of CO₂ can greatly affect a region's climate. Climate greatly impacts crop yield. Most of these indirect effects of increased atmospheric concentrations of CO₂ on crop yield are negative. However, the direct effects of the event on crop yield can be positive. For example, plants require CO₂ to conduct photosynthesis (E > B). Photosynthesis is the process by which plants absorb sunlight and convert it to chemical energy for growth. Scientists have determined that many types plants increase their rate of photosynthesis when they are grown under increased concentrations of CO₂. Increased rates of photosynthesis result in increased growth and increased yield. These effects have even been seen in plants grown in conditions that are too hot or too dry.

An ESS analysis of the impacts of increased concentrations of atmospheric CO₂ on the four spheres that make up the Kansas wheat farm ecosystem revealed many interesting contradictions. The direct effects of the event on the yield of hard-red winter wheat are positive. For example, as mentioned above, plants require CO₂ to conduct photosynthesis. They need to photosynthesize in order to grow. Increased atmospheric concentrations of CO₂ could increase the rate of photosynthesis within hard-red winter wheat. This could lead to increased growth and ultimately increased yield (E > B).

On the other hand, the indirect effects of the event on the yield of hard-red winter wheat are negative. Increased atmospheric concentrations of CO₂ may produce elevated temperatures as a result of the greenhouse effect. Elevated temperatures can speed up the water cycle and increase the rate of evaporation of water from the lithosphere. When the lithosphere becomes dry, it can no longer provide water to plants. Plants will wilt and die. Without plants to hold it in place, soil will be easily carried away by the wind (E > A > H > L > B > L > A). There will be no nutrient-rich topsoil remaining for croplands. The yield of crops such as hard-red winter wheat will decrease without moist, nutrient-rich soil to grow in. This effect was seen during the "Dust Bowl" in the southern plains of the United States during the 1930's.

Our firm has been able to predict how hard-red winter wheat will respond to increased atmospheric concentrations of carbon dioxide. We have also been able to predict how hard-red winter wheat will respond to climate changes. However we cannot, with certainty, predict the climate in Kansas 50 years from now. In addition, there are several varieties within the hard-red winter wheat class. Each of these varieties has been developed to withstand different growing conditions. It is possible that new varieties of this class of wheat will be developed to grow in the conditions of the climate in Kansas 50 years from now. Therefore, it is impossible to predict the yield of hard-red winter wheat in Kansas 50 years from now with much accuracy.

What are some hands-on activities?
Below are some internet resources for those teachers who like to use activities that are hands-on as well as minds-on.

The EPA Global Warming Kids Page

Canadian Global Change Program

NASA's Earth Observatory

Woodrow Wilson Leadership Program in Environmental Science

Michigan State University College of Education: Global Warming Unit

USDA - NASS Kids Home Page

NASS Kids-Educational Resources for Teachers.