Teaching the Complexities of Earth's Systems
An understanding of systems is integral to the study of the Earth.
By Lynsey Peterson
When teaching any science course, I try to emphasize the concept of systems. An understanding of systems is invaluable for students. It can help them grasp many concepts from homeostasis to weather to population dynamics. We start by brainstorming some examples of systems. Students usually think of the solar system and the body systems. We discuss how all systems have parts that work together for some overall function. The cell is the simplest living system, organisms are kept alive by various systems, and the complexities of ecosystems are just beginning to be understood.
In discussing systems, we learn about the three major types: open, closed, and isolated. Open systems exchange both matter and energy with other systems. Closed systems exchange energy, but not matter. Isolated systems do not exchange matter or energy. I ask students to identify which type of system the Earth is. Often, students say that the Earth is an open system, citing the input of energy from the sun and matter from meteorites and asteroids. While this is technically true, the amount of matter entering and leaving the Earth system is negligible in relation to the size of Earth itself. Because of this fact, Earth is considered to be a closed system. I relate the implications of this for environmental science with a discussion of limited natural resources and waste disposal options, as well as organisms’ need for a continuous input of energy from the sun.
The only system that does not have a continuous input of energy that we know of is the universe. Thus, the universe is an isolated system. Open systems include all of the systems within Earth. The hydrosphere, lithosphere, atmosphere, and biosphere all exchange matter and energy. These exchanges are of much interest to Earth and environmental scientists and make them complex and engaging fields of study.
I help my Earth and environmental science students consider the attributes of each of Earth’s systems with an introductory project. A small group of students begin by researching the topics and vocabulary of their system of choice. Depending on your class size and the size of the groups, you may need to assign each system once or twice. Once students have researched their system, they create a movie concept describing that system. I give them examples of real movies concerning Earth systems such as "Dante’s Peak," "The Day After Tomorrow," "Journey to the Center of the Earth," "Bio-Dome," and "Water World." As part of this project, I ask students to create a poster advertising their movie. They must give an idea of what the movie is about and use relevant vocabulary and concepts relating to their system. They present the posters and movie concepts to the class. This is a fun project that teaches the basic introductory information about the four open systems that make up the Earth system. Try these, and some of the other lessons below, to teach your students about the Earth's systems.
Earth's Systems Lesson Plans:
Students investigate the changes in Earth systems that occur during both human and geologic timeframes. They examine evidence of changes of Earth systems that take place in various time frames, and give examples of an Earth system process that has occurred.
Students investigate the age of the Earth by using accepted scientific methods. They conduct research about the use of radioactive dating by engaging in a simulation activity of the process. Finally, students measure the radioactive decay of actual rocks to estimate the actual age of the Earth.
Students investigate biological systems. They summarize relationships between systems. Students determine how systems relate within the biosphere, and perform an analysis of the carbon cycle.