ESS unit 1-4 + HL lenses

Perspective

how a particular situation is viewed and understood by an individual based on personal belief and assumptions

whats the difference between perspectives and arguements?

Arguements require supporting evidence to defend or challenge a perspective. whereas perspective is just a personal interpretation of a situation

whats a value?

a value are basic principles that people feel have worth and importance in life. these influence judgements, choices, and perspective

whats an Environmental value system

a model showing how inputs (like culture, media, and education) influence a person’s environmental perspectives, leading to different judgments and actions.

What are the 3 main components of an EVS?

1. Inputs – media, culture, religion, education, experiences

2. Processes – personal interpretation, values, decision-making

3. Outputs – actions, choices, policies, behavior toward the environment

What is anthropocentrism?

believes Humans are the most important species, and the environment should be managed for human benefit through laws, policies, and sustainable resource use

What is technocentrism?

Technology-centered; believes technology can solve environmental problems.

what is Eccocentrism?

believes that nature has its own intrinsic value. believes in minimal disturbance and sees humans as part of nature not above it

Indigenous knowledge

refers to the wisdom, skills, and practices that Indigenous peoples have developed over time based on their deep connection with their land and environment. It is passed down through generations and includes everything from traditional farming methods, medicine, and storytelling, to how they manage natural resources and understand the ecosystem.

Instrumental Values

nature is seen as useful for achieving something, like being a resource or providing benefits to humans. It’s about what nature can do for us.

Intrinsic values

Intrinsic values are the belief that nature has value simply because it exists, regardless of any usefulness to humans.

Relational values

describe the meaningful relationships between humans and nature.

They reflect how people value connection, identity, and responsibility with the environment — not just for usefulness (instrumental) or existence (intrinsic).

whats a system?

A system is a set of interconnected parts that work together to form a whole.

 inputs, processes, output

Open System

Exchanges both energy and matter with its surroundings.

Closed System

Exchanges energy but not matter with its surroundings

Isolated System

No exchange of energy or matter

components of a system:

Storages - Where energy or matter is held within the system

Inputs - What enters the system (matter or energy)

Outputs - What leaves the system

Flows - transformation(changed form during movement), and transfer(just movement)

Tipping Points

A tipping point is the minimum amount of change within a system that will destabilize it, causing it to reach a new equilibrium or stable state

• Resource consumption

• Habitat transformation and fragmentation

• Energy production and consumption

• Climate change

Resilience of a system

Resilience of a system is the capacity to resist damage and recover from or adapt to disturbances. Diversity(species that can adapt) and size of storage within a system contribute to its resilience and affect the speed of response to change.

eg When a diverse habitat undergoes major disturbances, one or more species likely have traits that help them adapt to the disturbances, reducing chances of local extinction.

Models

Models are simplified representations of reality used to understand and predict the behaviour of systems.

Benefits and Limitations of Models

Benefits:

• Models are used in science to show concepts on a scale that is accessible to a wider population.

• They allow us to look at different scenarios so that we can look at the impacts of different changes to the system.

• They allow us to simplify complex systems in order to study them more closely.

Limitations:

• Models can be oversimplified to the point that accuracy is lost.

• A common misconception is that models can provide exact predictions. Models can only offer approximations based on current knowledge and assumptions.

• Models and predictions depend on the skills and experience of the people making them.

Systems Diagrams

A system diagram is a visual representation of how a system works — showing how energy or matter moves between components through inputs, processes, outputs, storages, and flows.

feedback loops

flow diagram

positive / negative feedback loop

Positive Feedback: Amplifies changes, pushing the system away from equilibrium

Negative Feedback: Stabilizes a system by counteracting deviations, promoting equilibrium

Unit 1.3 Energy and equilibria

First Law of Thermodynamics

Energy cannot be created or destroyed, only transferred or transformed

Second Law of Thermodynamics

Energy transformations are not 100% efficient; some energy is lost (converted into heat), increasing system entropy (disorder)

Trophic levels

the stages in the food chain and each level represents how energy is transferred from one group of organisms to the next

Stable Equilibrium

A stable equilibrium is a state where a system returns to its original condition after a small disturbance.

In ecosystems, this might be seen in the population dynamics of predator-prey relationships.

Steady-State Equilibrium

Steady-state equilibrium is when a system stays stable over time due to equal inputs to outputs, even though energy and matter are constantly flowing through it.

Static Equilibrium

Static Equilibrium means no inputs or outputs, and no change over time.

        Examples; a stationary rock

Unstable Equilibrium

A system that does not return to its original state after disturbance.

Example: Deforestation leading to desertification.

what are some negative human Impacts on Ecosystem Resilience

Human activities can significantly affect ecosystem resilience:

1. Breaking up habitats: Reduces connectivity and biodiversity.

2. Pollution: Stresses organisms and alters ecosystem processes.

3. Overexploitation: Removes key species and disrupts food webs.

4. Climate change: Alters environmental conditions faster than many species can adapt.

give me a formula for Ecological efficiency

Ecological efficiency(%) = (energy transferred to the next trophic level / energy received by current trophic level) x 100

In a grassland ecosystem:

• Primary producers capture 10,000 kJ/m²/year of solar energy.

• Primary consumers utilize 1,000 kJ/m²/year.

• Secondary consumers utilize 100 kJ/m²/year.

Efficiency from producers to primary consumers: (1,000 / 10,000) × 100% = 10% Efficiency from primary to secondary consumers: (100 / 1,000) × 100% = 10%