ESS Unit 1 & 2.1

What is EVS ?

A worldview that shapes the way ppl perceive and evaluate environmental issues.

What is EVS influenced by ?

cultural, religious, economic and socio-political factors

3 Types of EVS ?

Ecocentric, Anthropocentric, Technocentric

Ecocentrism

nature centered - minimum disturbance of nature. puts ecology and nature as central to humanity. favors small scale, low technology lifestyles. ex : local products, avoid pesticides

Anthroprocentrism

ppl centered - humans are responsible for sustainable global systems thru control of population and resource use. views humankind as being the central, most important element. taxes, environmental regulation and legislation

Technocentrism

technology centered - technology can keep peace and provide solutions to environmental issues. believes there can be unlimited economic growth

System Diagram - the 5 systems and their representations

- Storages : box

- Flows : arrow

- Inputs : arrow in

- Outputs : arrow out

- Processes : ex. respiration, precipitation, diffusion

System definition ?

an assemblage of parts and their relationship forming a functioning entirety or whole

Systems involve :

Inputs, outputs and processes

What are Inputs / Outputs called?

Flows

What is the stock held called ?

Storages

Color / straightness of System Diagram Arrows of heat, energy, and matter?

- heat : wavy red arrow

- energy : straight red arrow

- matter : straight black arrow

Transfers ( a flow ) is ...

when a flow of energy / matter doesn't involve a change of form or state. There is normally a change of location.

ex : flow of water thru a river

Transformation ( a flow ) is ...

when a flow of energy / matter involves a change of state

ex : the water vapor turning into liquid as it cools down

Energy and matter flow thru ?

- Both energy and matter flow ( inputs / outputs ) thru ecosystems but are also stored within the ecosystem.

- Energy flows from 1 compartment to another but when 1 organism eats another the energy is in the form of stored chemical energy : flesh

Open Systems

exchange matter and energy with its surroundings

Closed Systems

exchange energy but not matter

Isolated Systems

no exchange of energy or matter with the outside

Stable Equilibrium

returns to the same equilibrium after the disturbance

Unstable Equilibrium

returns to a new equilibrium after a disturbance

Static Equilibrium

no change over time ( component of system remains constant over long period of time )

( Dynamic ) Steady-state Equilibrium

characteristics of open systems, continuous inputs and outputs but system as a whole remains more or less constant state ( small fluctuations )

Ex of a Dynamic Equilibrium

Predator-prey relationship

Feedback

- A system are continually affect by and react to info ( stimuli)

- The final outcome and the process is govervned by feedback

Positive Feedback ( - thing )

Amplifies or inc. change ; leads to exponential deviation from an equilibrium

Rev.Dojo: amplifies change, pushes system to
tipping point (e.g. permafrost melt releasing methane)

Negative Feedback ( + thing )

tends to damp down, neutralize or counteract any deviation from an equilibrium and promotes stability

Gaia Hypothesis

In the 1970's, James Lovelock and Lynn Marqulis argued that the Earth and its biological systems act as a single entitiy that has self-regulation negative feedback loop to keep conditions on Earth within a range favorable to life.

Gaia Hypothesis Argument is based on

- temp at the Earths surface is always constant

- composition of atmosphere is constant despite emissions

- ocean's salinity is constant despite rain, evaporation, etc..

Tipping Point *

Threshold level at which an environmental problem causes a fundamental and irreversible shift in the behavior of a system.

Tipping Points Involve [ 4 ]

- They involve + feedback

- Tipping point can't be predicted

- changes are long-lasting

- changes are hard to reverse

Ex of Tipping Points

- Lake Eutrophication

- Extinction of Species

- Coral Reef Death

Strengths of Models

- simplify complex systems ( easy to work w )

- allow predictions to be made about how systems will react in response to change --> so can help us see patterns

Limitations of Models

- not accurate bc a model is too simple

- results from models depend on the quality of the data inputs going into them --> so predictions can also be innacurate

Models of Systems Definition

A simplified version of reality and can be used to understand how a system works and predicts how it will respond to change

Ex of Models

- A physical model

- Mathematical eq.

- A software model

- Data flow diagram

3 Spheres of Sustainability

environmental, social, economic

environmental sphere

natural resource. use environmental management. pollution prevention ( ex : water, land, waste )