At this stage in your career, you should have encountered the term Earth system science, primarily used to describe the science (especially quantitative modeling) of the interactions between the atmosphere, hydrosphere and cryosphere, and biosphere. It should not require a huge leap in logic to see that the addition of lithosphere to that list provides all the components ("spheres") of the Critical Zone that we've studied this semester.
For a reminder and useful classroom video, see "Earth as a System [1]," a Quicktime video on the Teachers' Domain Web site.
Systems (in our case, the Critical Zone) consist of components (the "spheres"). The components are not isolated. Instead, they typically interact in complex ways; systems may also interact with other systems. These interactions, or linkages, are called couplings in Earth system science vocabulary. Positive couplings mean a change in one component, whether positive or negative, causes a change in the same direction in a linked component, whereas negative couplings mean the linked component undergoes change in the opposite direction. Feedback loops are circuits of change and response to change: negative feedback loops typically diminish the effects of change, whereas positive feedback loops usually amplify the change.
The state of a system is described using the characteristics of the system at a particular time. Changes to the state of a system are caused by (1) interactions between other systems and (2) interactions among the components within a system. An equilibrium state will not change unless the system is disturbed. Temporary disturbances to a system are called perturbations, whereas persistent disturbance is called forcing. When slight disturbances carry a system further from equilibrium it is said to be an unstable system.
In this final lesson of the semester, you will be introduced to some of the basic concepts of system modeling. We will accomplish this through a series of readings and an activity. The readings will introduce you to the basics of system modeling and some of the specifics (including quantification) of human impacts to the biosphere, atmosphere, hydrosphere, lithosphere, and soil (i.e., the Critical Zone). Your final task for the semester will be to create a qualitative Critical Zone system model.
Lesson 12 will take us one week to complete. As you work your way through these online materials for Lesson 12, you will encounter additional reading assignments and hands-on activities. The chart below provides an overview of the requirements for Lesson 12. For assignment details, refer to the lesson page noted.
Please refer to the Calendar in Canvas for specific time frames and due dates.
ACTIVITY | LOCATION | SUBMISSION INFORMATION |
---|---|---|
Create qualitative Critical Zone system model | page 3 | Submit to the "Lesson 12 - CZ System Model" dropbox in Canvas |
If you have any questions, please post them to our Questions? discussion forum (not e-mail), located under the Discussions tab in Canvas. I will check that discussion forum daily to respond. While you are there, feel free to post your own responses if you, too, are able to help out a classmate.
The goal of this final lesson is for you to create your own qualitative Critical Zone model, recognizing that the Critical Zone is a very complex system with human and natural components.
For this assignment, you may do your work by hand (e.g., pen/pencil and paper), in a word processing document, or using a drawing program of your choice. No matter what you choose, your work must be submitted in Word (.doc) or PDF (.pdf) format so I can open it.
L12_cz_system_model_AccessAccountID_LastName.doc (or .pdf)
For example, student Elvis Aaron Presley's file would be named "L12_cz_system_model_AccessAccountID_LastName.doc"—this naming convention is important, as it will help me make sure I match each submission up with the right student!
Upload your paper to the "Lesson 12 - CZ System Model" dropbox (in the lesson under the Modules tab) by the due date indicated on our Canvas calendar.
You will be graded on the quality of your writing. You should not simply write responses to the questions and submit them to me. Instead plan on writing a short stand-alone paragraph (or page or whatever you decide is necessary considering any constraints I might have placed on you) so that anyone can read what you've written and understood it. You should strive to be specific and complete in responding to the questions. Your answers should be analytic, thoughtful and insightful, and should provide an insightful connection between ideas. The writing should be tight and crisp with varied sentence structure and a serious, professional tone.
The activity entitled "Exploring environmental change [5]" provides an additional or optional mechanism for classroom introduction of the basic concepts of modeling an Earth system.
Humanity's impact on the Critical Zone is immense and often mostly negative, in the sense that the characteristics of and processes in the zone are diminished by our actions. By now you should have a sense that there are consequences to these actions and that the current status of humanity's relationship to the Critical Zone is not sustainable.
To learn more about human interactions with the various components ("spheres") of the Critical Zone system, complete the following reading assignment. As you do so, be sure to search for information regarding the characteristics, processes, and couplings of each component that may help you build your qualitative Critical Zone system model.
Articles not directly linked are located in Library Reserves.
To learn more about the basics of human population growth and effects on natural resources visit Population Education [8]. Pay particular attention to the "Environmental Connections" link and notice the teaching materials and tools, teacher services and workshops, and the free newsletter for teachers".
To consider an important view of tropical deforestation links to agriculture, food security and sustainability, see Iowa in the Amazon [9].
Remember that your task in this lesson is to create a qualitative Critical Zone system model, not a soil system model. While soil lies at the "heart" of the CZ, the zone is more than soil—soil may be thought of as a component of the CZ system.
Continue your readings of human interactions with the CZ by considering more specifically some of the effects we have on soil. Use this information to help build your CZ system model. (The articles below that are not directly linked are located in Library Reserves.)
From the introduction to this lesson, remember that human actions can be adaptive or excessive—thus far, much of our activity has been excessive, but we have the capacity to adapt and to be sustainable.
NOTE: The following readings are all available through Library Reserves.
Here are some additional resources that might be of interest:
The Critical Zone is a complex system formed at the intersection of the lithosphere, biosphere, hydrosphere and atmosphere, and including soils. In this lesson, you've learned about system modeling and considered human impacts on the Critical Zone and soil and adaptive measures that society can take to sustain the Critical Zone and soil. You also attempted to qualitatively model the Critical Zone by considering the various processes within each component of the CZ and how they are linked to the other components.
You have finished Lesson 12. Double-check the list of requirements on the Lesson 12 Overview page to make sure you have completed all of the activities listed there before beginning the next lesson.
If you have anything you'd like to comment on or add to, the lesson materials, feel free to share your thoughts with Tim. For example, what did you have the most trouble with in this lesson? Was there anything useful here that you'd like to try in your own classroom?
Links
[1] http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.hologlobe/
[2] https://www.e-education.psu.edu/earth530/sites/www.e-education.psu.edu.earth530/files/file/Campbell_ch55.pdf
[3] https://www.nationalgeographic.org/standards/national-geography-standards/14/
[4] https://www.ucar.edu/search?q=system+behavior+and+system+modeling
[5] http://www.teachersdomain.org/resource/echo07.sci.life.coast.lpenvironment/
[6] http://www.worldproutassembly.org/archives/2006/04/the_causes_of_t.html
[7] https://www.ipcc.ch/report/ar5/wg2/freshwater-resources/
[8] http://www.populationeducation.org
[9] http://www.nytimes.com/2013/11/25/opinion/iowa-in-the-amazon.html?pagewanted=all&_r=0
[10] http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.flooderosion/
[11] http://www.sciencemag.org/cgi/content/full/304/5677/1616/DC1
[12] http://www.teachersdomain.org/resource/ipy07.sci.ess.earthsys.arcticland/
[13] http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.organic/