Environmental Systems Topic - 1 Systems and Models Statements 1.A – 1.G

What is Environmental Systems About? In this course we will be studying and analyzing the environment as a set of complex systems. We won’t look at them separately as a biologist, geologist, or earth scientist would - but as all three professions combined.

So what is a system? Systems are sets of entities that function as a whole. A group of parts connected together in an organized way to make a more complex entity.

Examples of Systems

The System that we will study most…. The Ecosystem - a community of organisms in its abiotic environment, together with the relationships amongst these components.

Every system has a boundary Outside of that boundary lies the system’s environment. Environment: everything outside of a system that can influence the system or can be influenced by the system. -Therefore different systems can be linked.

Diagraming Systems All systems have: Represented by: STORAGES or stocks of matter and energy. FLOWS into, through, and out of the system INPUTS OUTPUTS BOUNDARIES PROCESSES which transfer and transform energy or matter A box Size of box represents amount. Arrows Arrows in Arrows out Lines Arrows between storages

Stock size is dependent on both the input and the output. Tree farm planting = cutting Stock size is dependent on both the input and the output. Use of Fossil fuels Pollution of lakes with pesticides

Transfers within a system Transfer - when matter or energy is moved from one location to another. Examples? Come up with at least 5 transfers and transformations with those around you.

Transformations within a System Transformation - interaction within a system that forms a new end product or involves a change in state. Examples?

Open Systems A type of system that exchanges matter and energy across its boundary with its environment. Therefore, these systems exchange factors with other systems around them. Almost all systems are open systems.

Diagram of an Open System

Closed System A system that exchanges energy with its environment but not matter. Closed systems are not found in nature. But globally, the cycles of matter can be thought of as closed systems Ex: How could you diagram a closed system?

Isolated Systems A System that exchanges neither matter nor energy with its environment. This cannot exist. Possible exception??? Students stand up and pair up. Student 1 – define Open; Student 2 – example Open Student 2 – define Closed; Student 1 – example Closed Student 1 – define Isolated; Student 2 – example Isolated

The First Law of Thermodynamics First Law - Energy may not be created or destroyed, but may change from one form to another. AKA - The Law of Conservation of Energy What does this mean? Examples?

The Second Law of Thermodynamics What is needed for any system to be sustaining? What happens to energy in a system? This is called the Second Law of Thermodynamics – Entropy or disorder in a system increases over time. Why? Eventually, all energy is emitted back into the environment as unusable heat, but it is NOT destroyed. Example?

Second Law of Thermodynamics Stand up, pair up with someone new in area. Describe one thing you understand about the Laws of Therm to each other. Ask each other a question that you would like explained about the Laws. Because energy is decreasing over time or through a system, what do all systems need to have?

While energy is continuously flowing through systems….

matter tends to circulate around inside of it.