A system is an entity which maintains its existence through the mutual interaction of its parts, and each part is a system unto itself. All life forms are systems, but there are also inorganic systems too. Earth is one of them - it has life, but without the inorganic components, there would not be life here. A concept map of the fundamental Earth systems components is below, and these will be the main focus for the Earth Systems arc.
Earth systems involves the interactions between energy flows, matter cycles, and life webs, or you could consider how the atmosphere (gases), biosphere (life), cryosphere (ice), geosphere (rock), and hydrosphere (water) interact. Both are useful ways to think about how Earth systems have developed and supported complex life over much of its 4.5 billion years of existence. With each additional component you consider, the complexity of the system becomes more apparent.
By exploring systems it:
1) Parking lot the systems that make you (explore Concept Mapping to familiarize yourself). Don't just focus on your biological systems, but consider your educational, social, and support systems as well.
2) Connect the systems and add verbs to the links that describe how one system affects another.
3) Brainstorm how an individual makes up systems larger than itself.
Suggested Time: 30-45 min if already explored concept maps.
Read Parachuting Cats, identify all of the components described in the story and map out how they are connected and add action verbs to the links.
If possible, work in teams of two or three. And if there are several teams, compare concept maps and try discuss the strengths of each. Then, the teams create a new concept map.
Now create a concept map of the system before DDT was sprayed. Once you have an agreed upon map, mark the expected changes that the World Health Organization could have anticipated prior to spraying the DDT. This is an example of identifying unintended consequences when the system is consider prior to making a change to it.
Since a system's components are highly interconnected, a change to one component often creates changes throughout the system, as was seen in Borneo. This arc focuses on Earth's system without the influence of humans, but if you understand this system, it is easier to understand how Earth responds to the vast changes humans are creating.
Suggested Time: 45-60 min if already familiar with concept mapping.
More Examples of Systems
There are vast amounts of information available on the following topics:
Since systems are made up of interconnected processes, sometimes the connections work to amplify the response to a change in the system, pushing it toward an extreme condition. This occurs when the component that originally altered the system is being changed continually in the same manner as the initial change by the response within the system. This is called a positive feedback.
Other times, a change in the system creates a balanced, stable response that is not an extreme condition. This is known as a negative feedback.
In today’s world, positive and negative are used in many ways that can make this confusing to remember. For example, positive feedback at school is welcome, whereas, positive results for a medical test can be quite scary.
Many of us have experienced a positive feedback whenever we’ve heard a blaring sound coming from a speaker system at a mic check in an auditorium prior to a musical performance. Microphones convert sound to electrical signals that are then amplified and sent to a speaker which converts the electrical signal back to sound that is louder than the original sound that entered the microphone. If the microphone is close enough to and/or oriented toward the speaker to detect the amplified original sound, then the system amplifies the already amplified sound. The system continues this in a positive loop, and we hear a very loud, painful sound coming from the speaker (see concept map of this positive feedback above).
Earth’s system has many feedback loops, many of which create negative feedback that help Earth maintain a moderate range of climate response to changes in the system. But there are some positive loops within the system that can create dramatic, if not extreme, conditions on Earth. One is known as the Arctic or polar amplification (concept map above). Snow forms in cold conditions, and if the temperature stays below freezing throughout the year, the snow may eventually be compressed to ice. Both ice and snow are highly reflective of the Sun’s radiant energy, so when present, the region becomes colder, which allows snow to form and last at lower latitudes , helping the ice to form at lower latitudes. Ultimately the ice extends further and further from the poles over time. Conversely, if the climate warms due to some process, snow and ice melt during the summer months, exposing either land or water, both of which absorb considerable amounts of sunlight, so the region warms more, melting more snow and ice in the region, and the ice retreats toward the poles.
Studying the Earth as a system allows us to identify positive and negative feedback loops, helping scientists improve their research of how Earth has responded and will respond to changing conditions on Earth through time. Consider using concept maps as a tool to visualize positive and negative feedback within a system.