1.2 - Systems

Question 1

what is a systems approach

Answer 1

the term used to describe a method of simplifying and understanding a complicated set of interactions

Question 2

two ways of studying systems

Answer 2

• reductionist approach
• hollistic approach

Question 3

what is a reductionist approach

Answer 3

breaking a system down into its parts and studying each one individually

Question 4

what is a hollistic approach

Answer 4

A holistic approach looks at all of the system’s processes and interactions as a whole

Question 5

components of a system

Answer 5

• storages
• flows

Question 6

processes in a system

Answer 6

• transfers
• transformations

Question 7

what is a transfer

Answer 7

the movement of matter or energy from one component of the system to another without any change in form or quality

Question 8

what is a transformation

Answer 8

a change in the form or quality of matter or energy as it moves through the system

Question 9

how are storages and flows drawn in a systems diagram

Answer 9

storages - shape with clear boundaries e.g. rectangle

flows - arrows

Question 10

what are emergent properties

Answer 10

properties of a system that appear as individual system components interact; the components themselves do not have these properties

Question 11

what are open systems

Answer 11

when both energy and matter are exchanged between the system and its surroundings. Most systems are open systems

Question 12

what are closed systems

Answer 12

Energy, but not matter, is exchanged between the system and its surroundings

Question 13

what are isolated systems

Answer 13

Neither energy nor matter are exchanged between the system and its surroundings. Isolated systems do not exist naturally.

Question 14

what are systems

Answer 14

structures made up of interconnected parts that work together towards a common goal or function

Question 15

what is the Gaia Hypothesis

Answer 15

• The Gaia hypothesis, initially proposed by James Lovelock, presents a holistic view of the Earth as a single, self-regulating system
• Lovelock proposed that Earth’s biota (living organisms) and their environment are closely linked and act together as an integrated system
• His theory suggests that feedback mechanisms within Earth’s systems help maintain stability and balance on a global scale

Question 16

what is an equillibrium

Answer 16

a state of balance occurring between the separate components of a system

Question 17

what is a steady-state equilibrium

Answer 17

• A steady-state equilibrium occurs when the system shows no major changes over a longer time period, even though there are often small, oscillating changes occurring within the system over shorter time periods
• These slight fluctuations usually occur within closely defined limits and the system always returns to its average state`

Question 18

what is static equilibrium

Answer 18

There are no inputs or outputs (of energy or matter) to the system and therefore the system shows no change over time

Question 19

what are negative feedback loops

Answer 19

Negative feedback is any mechanism in a system that counteracts a change away from equilibrium
- Negative feedback loops occur when the output of a process within a system inhibits or reverses that same process in a way that brings the system back to its average state
- In this way, negative feedback is stabilising—it counteracts deviation from equilibrium
- Negative feedback loops stabilise systems

Question 20

what are positive feedback loops

Answer 20

• Positive feedback is any mechanism in a system that leads to additional and increased change away from equilibrium
• Positive feedback loops occur when the output of a process within a system feeds back into the system in a way that moves the system increasingly away from its average state
• In this way, positive feedback is destabilising—it amplifies deviation from equilibrium and drives systems towards a tipping point where the state of the system suddenly shifts to a new equilibrium

Question 21

what is a tipping point

Answer 21

Tipping points are a point at which an ecosystem can no longer cope with environmental change, and the ecosystem suddenly shifts from one state to another, away from equilibrium

Question 22

what is resilience

Answer 22

the system’s ability to maintain stability and avoid tipping points

Question 23

what is a model

Answer 23

a simplified version of reality

A model is often used to represent a system

Question 24

strengths of models

Answer 24

• simplify complex systems
• allow predictions to be made about how systems will react in response to change
• System inputs can be changed to observe effects and outputs without the need to wait for real-life events to occur
• Models are easier to understand than the real system
• Results from models can be shared between scientists, engineers, and companies and communicated to the public
• Results from models can warn us about future environmental issues and how to avoid them or minimise their impact

Question 25

limitations of models

Answer 25

- Models can be oversimplified and inaccurate - Results from models depend on the quality of the data inputs going into them - Results from models become more uncertain the further they predict into the future - Different models can show vastly different outputs even if they are given the same data inputs - Results from models can be interpreted by different people in different ways - Environmental systems are often incredibly complex, with many interacting factors—it is impossible to take all possible variables into account