ESS Standard Topic 1.2

Systems and Models

Systems Approach

A holistic approach to visualise a complex set of interactions

System

Is made up of individual parts that are working together to preform a function

What is a System Composed of?

• Storages

• Flows - Give inputs and Outputs of energy and matter

What can flows between Storages be classed as?

• Transfers - Change in Location

• Transformations - change in state, energy or chemical nature

What are the 3 types of Systems?

• Open - Exchange of Matter and Energy

• Closed - Exchange of Energy

• Isolated - Exchange of jack shit

What was the Biosphere 2 experiment?

A prototype space city, a human attempt to create closed system on Earth built in Arizona in the later 1980s meant to explore the use of close biospheres in space colonization.

Problems

• It couldn’t produce enough food to sustain participants

• Oxygen levels fell dangerously low 21%-14%

• Participants opened windows to let air in ruining the experiment.

• 25 species introduced and 19 of them went extinct with mainly insects surviving.

• CO2 levels fluctuated a lot.

The second trail in 1994 was vandalized by people opening doors etc and there were social, biological and technological problems.

What did the Biosphere 2 experiment show

That it is extremely difficult to make a sustainable closed system.

Model

A simplified representation of a complex concept or senario

Name the 6 spheres. (Idk what there called)

• Biosphere - All living organism and their interactions

• Hydrosphere - All the Earths water bodies

• Cryosphere - Areas covered in ice and snow

• Geosphere - Solid rocks and minerals

• Atmosphere - Layer of gas surrounding the Earth

• Anthroposphere - Human activity and their Impacts

Positive Feedback loop

Amplifies or increases change promoting deviation from equilibrium. (Actually Bad

(Presented by cycles that circle back)

E.g. Albedo Effect.

Negative Feedback Loop

Neutralizes or Counteracts and deviation from equilibrium and promotes stability.

(Presented linearly)

E.g. The Lynx loop (Prey Interaction)

Equilibrium

State of balance

Steady-Sate Equilibrium

Where there are continuous inputs and outputs

Stable Equilibrium

Where the system will return to the original equilibrium after disturbance.

Unstable Equilibrium

Where the system does returns to a new equilibrium after disturbance. 

Resilience

Refers to the tendency to avoid tipping points and maintain stability

What makes a system with High resilience?

Larger ecosystems, large storages and Higher Biodiversity with Species of faster reproductive rates.