Environmental Systems And Societies - Systems And Models

Front 1

What is a system?

Back 1

A system is an organized collection of inter-dependent components that perform a function. They are connected through the transfer of energy and/or matter

All parts of a system are linked and affect each other

Front 2

What are inputs?

Back 2

Resources (typically energy such as sunlight or nutrients) that 'power' a system to allow it to function. Without inputs, a system cannot function

Front 3

What are flows?

Back 3

Flows of matter or energy within a system at certain rates (calories and proteins into the human metabolism)

Front 4

What are outputs?

Back 4

Outputs are 'end products' things that are a result of events that occur within a system such as heat and smoke being an output of a burning candle

Front 5

What are storages?

Back 5

Parts of a system that allows energies and/or matter to accumulate and gather for a time after usage (an example might be fats in the body)

Front 6

What are transfers?

Back 6

An event wherein energy or matter moves through a system and changes in location. E.g. Heat conducted through metals from a fire into a metal

Front 7

What are transformations?

Back 7

Transformations are interactions that occur within a system wherein energy and/or matter forms a new end product or a change of state. E.g. electricity energy turned into light energy in a lightbulb or burning a fossil fuel to make heat energy or light energy being absorbed by plants

Front 8

What is an open system?

Back 8

A system where matter and energy are exchanged across boundaries of the system. Most natural living systems are open systems

Front 9

What is a closed system?

Back 9

Energy is exchanged across boundaries of the system but matter is not. E.g. chemical cycling

Front 10

What is an isolated system?

Back 10

A hypothetical system in which neither energy or matter is exchanged across boundaries of the system

Front 11

What are the two different scales?

Back 11

Micro and Macro

Front 12

What does the scale mean on the micro-level?

Back 12

Micro scales refer to smaller systems such as those of a pond

Front 13

What does the scale mean on the macro-level

Back 13

Macro scales refer to those that are bigger such as eco-systems like rainforest. A planet may be considered a macro-scale but they can be identified as a 'global ecosystem'

Front 14

What is the First Law of Thermodynamics

Back 14

Conservation of energy dictates that energy absorbed remains inside a system as it cannot be created or destroyed

Front 15

What is the Second Law of Thermodynamics?

Back 15

Energy in a any isolated system, disorder (entropy) tends to increase spontaneously. The amount of energy available to do work decreases.

In other words: Energy is always used up in energy transformation

Front 16

What is a steady-state equilibrium?

Back 16

A system where there are continuous inputs and outputs. There occasional changes that imbalance however these are temporary and short-lived and so the system becomes balance shortly thereafter.

E.g. electricity flowing in and out of a computer

Front 17

What is a static state equilibrium?

Back 17

An unchanging system like a desert. When a static system is disturbed a new equilibrium is formed

Front 18

What is the difference between positive and negative feedback?

Back 18

Positive feedback destabilizes a system. E.g. more pollution in an environment kills off animals

Negative feedback stabilizes a system. E.g. plants or people recycle and get rid of pollution in an environment

Front 19

Which kind of feedback makes a system more stable: negative or positive?

Back 19

Negative

Front 20

How does negative feedback help regulate the population of organisms?

Back 20

When overpopulation ensues, a lack of food occurs thus a majority of the population dies out or migrates to find food elsewhere. When this happens, the food source replenishes and gradually over time the organism population returns again.

Front 21

Why are most ecosystems negative feedback loops?

Back 21

Ecosystems are capable of resetting themselves frequently after a population growth has occurred and kills off the organisms that overpopulate to replenish itself and allows the organism to come back

Front 22

Why are human populations less prone to negative feedback loops?

Back 22

One possible reason is overpopulation followed by overconsumption. Because there are so many humans in the world that require so many resources. It is necessary for the continued survival of humans to exploit and use up as much matter/energy we need to survive.

Another possible reason is technologically we have reached a point wherein we can exploit more resources to ensure our survival