Systems Thinking

Subtopic 1.2 β€” New Syllabus (First Assessment 2026)
Standard Level + Higher Level

🌍
18 SL Syllabus Points
1.2.1 – 1.2.18
πŸ”„
Core Content Focus
Systems, Feedback & Resilience
Topic Overview

How do systems function and how can systems thinking help us understand environmental issues?

Content Map:
A. Systems (Syllabus points 1.2.1–1.2.9)
Foundations β€” what systems are, how they are structured, modelled, and described.

B. Feedback Loops (Syllabus points 1.2.10–1.2.13)
Mechanisms β€” how systems self-regulate or amplify change.

C. System Resilience (Syllabus points 1.2.14–1.2.18)
Adaptation β€” how systems absorb disturbance, shift states, and integrate human dimensions.

Systems thinking is a conceptual framework that examines how components within a system interact to produce behaviour that cannot be understood by looking at individual parts in isolation. In Environmental Systems and Societies (ESS), systems thinking is the foundational approach for understanding all environmental interactions β€” from nutrient cycles in ecosystems to global climate dynamics.

πŸ“Œ Why This Matters: Every topic in ESS (from biodiversity to pollution) is best understood through a systems lens. Mastering 1.2 gives you the conceptual toolkit for the entire course.
1.2.1

What is an Environmental System?

An environmental system is a collection of components that interact with each other and their physical environment to form a functional whole.

Key Understanding: Every environmental system is defined by three essential properties:
1. Interactions β€” components influence each other
2. Interdependence β€” components rely on one another for function
3. Complexity β€” the number and nature of interactions create non-linear behaviour

Examples of Environmental Systems

System Components Interactions
Forest ecosystem Trees, soil, fungi, insects, water cycle, sunlight Nutrient cycling, competition, predation, photosynthesis
Urban drainage system Impervious surfaces, drains, rivers, groundwater Runoff, infiltration, flooding, sediment transport
Global carbon system Atmosphere, oceans, biosphere, lithosphere Photosynthesis, respiration, combustion, dissolution
βœ… Exam Tip: When asked to "outline the properties of an environmental system," always address all three properties: interactions, interdependence, AND complexity. Use a specific example to illustrate each.
1.2.2

Structure, Function, and Emergent Properties

Systems have three fundamental characteristics: structure (what it is), function (what it does), and emergent properties (what arises from interactions).

Characteristic Definition Example (Lake Ecosystem)
Structure The components and their relationships Fish, algae, zooplankton, dissolved oxygen, nutrients, sediment
Function Energy flows and matter cycling through the system Sunlight β†’ algae photosynthesis β†’ zooplankton grazing β†’ fish predation β†’ decomposition β†’ nutrient recycling
Emergent Properties Properties arising from interactions that do not exist in individual components Water clarity, species diversity, trophic stability, primary productivity
Key Understanding: Emergent properties are the defining feature of systems thinking. You cannot predict or observe them by studying components in isolation β€” they only exist because of how parts work together.

Another Example: Wetland Water Purification

A wetland's ability to filter pollutants is an emergent property. No single plant, microbe, or sediment grain can filter water alone β€” it is the combination of microbial decomposition in anaerobic sediments, nutrient uptake by plants, and physical filtration by root networks that produces this function.

⚠️ Common Mistake: Confusing "function" with "structure." Structure = the parts. Function = what happens (flows of energy/matter). Emergent properties = what arises that cannot be reduced to individual parts.
1.2.3

Open, Closed, and Isolated Systems

Systems are classified by how they exchange energy and matter with their surroundings.

Systems Thinking in ESS Diagram
System Type Energy Exchange Matter Exchange Real-World Example
Open system Yes Yes Most natural systems β€” e.g., forest (receives sunlight, exchanges water vapour, nutrients)
Closed system Yes No Earth as a whole (energy in/out via radiation; matter largely conserved except for meteorites)
Isolated system No No Theoretical only β€” no real system is truly isolated. Sometimes used as a simplification.
Key Understanding: Most natural systems are open systems. They require continuous inputs of energy and matter. When inputs are disrupted, the system's behaviour changes β€” this is why resource depletion and pollution matter.
β˜€οΈ Solar Energy
β†’
🌿 Ecosystem (Open System)
β†’
πŸ’¨ Heat + Water Vapour
πŸ“Œ Note: The Earth is sometimes described as a closed system with respect to matter. This is why the Law of Conservation of Mass matters β€” matter cycles but is neither created nor destroyed on Earth (with minor exceptions like atmospheric escape of hydrogen).
1.2.4

Modelling Systems

Systems can be modelled using diagrams, mathematical equations, and computer simulations. Models simplify reality to help us understand complex interactions.

Model Type Description Strengths Limitations
Physical model Tangible, scaled representation (e.g., a diorama, a wind tunnel model) Intuitive; allows direct observation Cannot capture all interactions; expensive to build
Conceptual model Diagrammatic representation (e.g., systems diagram, food web) Visualises relationships; identifies feedback loops Qualitative; may oversimplify
Mathematical model Equations describing relationships (e.g., population growth models) Precise; testable; predictive Requires data; sensitive to assumptions
Computer simulation Programmed model that can run scenarios (e.g., climate models) Can handle large complexity; scenario testing "Black box" problem; requires technical expertise
Key Understanding: All models simplify reality. They make assumptions. The value of a model is not that it is "true" but that it helps us understand, predict, and manage systems more effectively.
βœ… Exam Tip: If asked to evaluate a model, identify at least one strength and one limitation. A common question asks you to draw a systems diagram β€” practise this using the components, flows, and feedback loops for specific case studies.
1.2.5

Systems Thinking

Systems thinking involves understanding how parts of a system interact to produce emergent properties. It requires looking at the whole system, not just individual components.

Key Understanding: Systems thinking is the opposite of reductionism. Reductionism breaks a system into parts to study it. Systems thinking examines how the interactions between parts produce behaviour that cannot be predicted from the parts alone.

Key Principles of Systems Thinking

  1. Holism β€” the whole is greater than the sum of its parts
  2. Interconnectedness β€” changing one component affects others
  3. Non-linearity β€” cause and effect are not always proportional or immediate
  4. Feedback β€” outputs become inputs, creating circular causation
  5. Mental models β€” our understanding of systems shapes how we act within them

Example: Deforestation Through a Systems Lens

A reductionist approach might focus on the number of trees cut. A systems thinking approach would consider:

πŸ“Œ Note: The IB ESS course is explicitly built around systems thinking. Every topic (2–7) applies systems thinking to a specific environmental issue. Your ability to demonstrate systems thinking in written responses is directly assessed.
1.2.6

Inputs, Processes, Outputs, and Feedback

Any system can be described in terms of inputs, processes (throughputs), outputs, and feedback.

INPUT
Energy, matter, information
β†’
PROCESS
Transformations within the system
β†’
OUTPUT
Products, waste, heat
β†’
FEEDBACK
Output influences future inputs
Element Definition Example: Forest Ecosystem
Input What enters the system from outside Solar radiation, rainfall, atmospheric COβ‚‚
Process What happens inside the system Photosynthesis, decomposition, nutrient cycling, growth, predation
Output What leaves the system Evapotranspiration, leaf litter, oxygen, heat
Feedback How outputs influence future system behaviour Increased COβ‚‚ β†’ increased growth β†’ more shade β†’ reduced understorey growth
Key Understanding: This IPOF (Input–Process–Output–Feedback) framework is the foundational model for analysing any system. Practise applying it to ecosystems, human systems, and social-ecological systems.
1.2.7

Hierarchical Systems

Systems are hierarchical β€” they are composed of smaller subsystems, and they are nested within larger supersystems.

🌍 Biosphere
(Supersystem)
β†’
🌲 Forest Ecosystem
(System)
β†’
🐾 Population
(Subsystem)
β†’
πŸ› Individual
(Sub-subsystem)
Key Understanding: Each level of the hierarchy has its own emergent properties that do not exist at other levels. A population exhibits growth rate and carrying capacity β€” properties that an individual organism does not possess.

Hierarchy in Practice

Level Example Emergent Properties at This Level
Individual A single oak tree Growth rate, photosynthetic efficiency
Population All oak trees in a forest Population density, age structure, carrying capacity
Community All species in a forest Species diversity, trophic structure, competitive exclusion
Ecosystem Forest + soil + climate + hydrology Nutrient cycling, primary productivity, energy flow
Biosphere All ecosystems on Earth Global biogeochemical cycles, climate regulation
βœ… Exam Tip: When analysing a case study, explicitly identify the level of hierarchy you are examining. This shows sophisticated systems thinking and is rewarded in marking criteria.
1.2.8

System Boundaries

Boundaries define what is inside and outside a system. They can be real (physical β€” e.g., a shoreline) or conceptual (imposed by the observer β€” e.g., defining "a wetland").

Key Understanding: The choice of boundary affects what we study. A boundary drawn around a single field ignores upstream pollution. A boundary drawn around a whole river catchment captures it β€” but makes the system much more complex to analyse.

Factors Influencing Boundary Selection

Example: Water Quality Study

Boundary Choice Advantage Limitation
Single farm paddock Detailed data; direct land management link Misses upstream/downstream effects
Entire river catchment Captures all inputs and outputs Data-intensive; harder to isolate causes
Political boundary (e.g., county) Aligns with governance and policy May not reflect natural system dynamics
⚠️ Common Mistake: Assuming boundaries are always fixed and natural. In ESS, boundaries are often chosen by the researcher or manager β€” and different boundaries lead to different conclusions.
1.2.9

Stocks and Flows

A system's state can be described by its stocks (accumulations of matter, energy, or information) and flows (rates at which stocks change).

Stockending = Stockbeginning + Inflows βˆ’ Outflows
System Stock Inflow(s) Outflow(s)
Population Number of individuals Births, immigration Deaths, emigration
Lake Volume of water Rainfall, river inflow, groundwater Evaporation, outflow, seepage
Atmospheric COβ‚‚ Concentration (ppm) Respiration, combustion, deforestation Photosynthesis, ocean absorption
Soil nutrients Nutrient concentration Decomposition, fertiliser application Plant uptake, leaching, erosion
Key Understanding: When inflows = outflows, the stock is in dynamic equilibrium. When inflows β‰  outflows, the stock changes. Environmental problems often arise when human activity disrupts the balance between inflows and outflows (e.g., extracting groundwater faster than it recharges).
βœ… Exam Tip: Practise identifying stocks and flows for case studies. This is a powerful analytical tool for 6-mark explanation and 9-mark essay questions.
1.2.10

Feedback β€” An Overview

Feedback occurs when the output of a system feeds back as an input, modifying the system's subsequent behaviour. Feedback is what makes systems dynamic rather than linear.

Output
β†’
Feedback Loop
β†’
Modified Input
β†’
Changed System Behaviour
Type Effect Result Analogy
Negative feedback Opposes change Stabilisation; equilibrium Thermostat β€” when temperature rises, heating turns off
Positive feedback Amplifies change Destabilisation; runaway change; potential tipping points Microphone feedback β€” small signal β†’ louder β†’ louder β†’ screech
Key Understanding: "Negative" does not mean "bad" and "positive" does not mean "good." Negative feedback promotes stability. Positive feedback promotes change. Both are essential for system function β€” but excessive positive feedback can push systems past tipping points.
1.2.11

Negative Feedback

Negative feedback opposes change and tends to stabilise systems by returning them to their original state after a disturbance. It maintains equilibrium.

Case Study: Predator–Prey Dynamics (Canadian Lynx and Snowshoe Hare)

πŸ‡ Hare population increases
β†’
🦊 Lynx have more food β†’ lynx population increases
β†’
More predation β†’ hare population decreases
β†’
Less food β†’ lynx population decreases
β†’
Less predation β†’ hare population recovers

This creates a cyclical, self-regulating oscillation that has been documented in Hudson Bay Company fur records spanning over 200 years.

Other Examples of Negative Feedback

System Negative Feedback Mechanism
Human body Body temperature rises β†’ sweat glands activated β†’ evaporative cooling β†’ temperature returns to normal
Ocean pH Increased COβ‚‚ β†’ ocean absorbs more β†’ COβ‚‚ dissolves β†’ atmospheric COβ‚‚ decreases
Grassland Overgrazing β†’ grass biomass declines β†’ livestock food availability drops β†’ grazing pressure reduces β†’ grass recovers
Atmosphere Higher temperature β†’ increased evaporation β†’ more clouds β†’ more solar reflection β†’ temperature decreases
Key Understanding: Negative feedback is the primary mechanism that maintains dynamic equilibrium in systems. Without negative feedback, systems would be inherently unstable.
1.2.12

Positive Feedback

Positive feedback amplifies change and tends to destabilise systems, potentially pushing them past tipping points to new, often irreversible states.

Case Study: Ice-Albedo Feedback (Arctic)

🌑️ Temperature rises
β†’
🧊 Ice melts β†’ darker ocean/land exposed
β†’
β˜€οΈ Darker surface absorbs more solar radiation
β†’
🌑️ More warming β†’ more ice melts

This loop accelerates warming in the Arctic far faster than the global average β€” a phenomenon known as Arctic amplification.

Other Examples of Positive Feedback

System Positive Feedback Mechanism Potential Tipping Point
Permafrost Warming β†’ permafrost thaws β†’ releases CHβ‚„ and COβ‚‚ β†’ more warming Large-scale permafrost collapse; irreversible carbon release
Deforestation Forest cleared β†’ less transpiration β†’ less rainfall β†’ drier conditions β†’ more forest stress and fire Savannification of tropical forest (e.g., Amazon)
Ocean circulation Ice sheet melt β†’ freshwater inflow β†’ reduced thermohaline circulation β†’ altered climate patterns Collapse of Atlantic Meridional Overturning Circulation (AMOC)
⚠️ Critical Concept: Positive feedback loops are the mechanism behind tipping points (see 1.2.16). Once a positive feedback loop dominates, a system can rapidly shift to a new state that may be difficult or impossible to reverse.
1.2.13

Multiple Feedback Loops

Most real systems have both positive and negative feedback operating simultaneously. The balance between them determines overall system behaviour.

Case Study: Coral Reef System

Feedback Type Mechanism Effect
Negative Herbivorous fish graze algae β†’ prevents algal overgrowth β†’ coral recruits successfully Stabilises reef; maintains coral dominance
Negative Coral growth provides structural habitat β†’ supports fish populations β†’ more herbivory Self-reinforcing stability
Positive Coral bleaching β†’ less live coral β†’ fewer fish β†’ less herbivory β†’ more algae β†’ less coral recovery Accelerates degradation; potential phase shift
Positive Warming β†’ bleaching β†’ reduced photosynthesis β†’ less energy for reproduction β†’ fewer coral larvae Reduces recovery capacity
Key Understanding: When negative feedback dominates, the system is resilient and stable. When positive feedback dominates (often due to external stress), the system can shift rapidly. Understanding the balance between feedback types is key to predicting system behaviour.
πŸ“Œ Implication for Management: Effective environmental management aims to strengthen negative feedback loops (e.g., protecting herbivorous fish populations) and weaken positive feedback loops (e.g., reducing stressors that trigger bleaching cascades).
1.2.14

System Resilience

System resilience is the ability of a system to recover from disturbance and return to its original state. A resilient system absorbs change without fundamentally altering its structure and function.

Key Understanding: Resilience is not the ability to avoid change β€” it is the ability to recover from change. It depends on the system's internal properties (diversity, connectivity, redundancy) and the magnitude and frequency of disturbances.

Resilience vs. Resistance

Property Definition Example
Resistance Ability to withstand disturbance without change A hardwood forest resisting a small fire
Resilience Ability to recover after disturbance A grassland regrowing after fire

A system can be highly resilient (recovers quickly) but not very resistant (changes easily), or vice versa. These are different properties.

1.2.15

Factors Affecting Resilience

Three key properties determine a system's resilience:

Multiple decomposer species in soil β€” if one is lost, decomposition continues

Factor Definition How It Builds Resilience Example
Biodiversity Number and variety of species More species = more functional alternatives; if one species declines, others can fill its role Tropical rainforest β€” thousands of species mean high functional redundancy in pollination
Connectivity How components are linked High connectivity allows rapid transfer of energy/matter/information; can also spread disturbance Coral reef channels connecting lagoon and open ocean maintain larval supply
Redundancy Duplication of functional roles Multiple species performing the same function means loss of one is not catastrophic
Key Understanding: Redundancy is NOT waste β€” it is a critical feature that maintains system function under stress. Removing "redundant" species (which seems efficient in the short term) reduces resilience.

Connectivity: A Double-Edged Sword

While high connectivity generally supports resilience, it can also allow disturbances to spread more rapidly. For example, highly connected food webs can transmit disease faster, and interconnected financial markets can propagate economic crises.

⚠️ Exam Warning: If asked about connectivity and resilience, acknowledge that high connectivity is generally beneficial but can also facilitate spread of invasive species, disease, or pollution across the system.
1.2.16

Tipping Points

A tipping point is a threshold beyond which a system shifts to a new state, often irreversibly. Once crossed, the system reorganises around new feedback loops that maintain the new state.

Key Understanding: Tipping points are often triggered when positive feedback loops begin to dominate. Once the threshold is crossed, the system may settle into a new stable state β€” one that is typically less beneficial for the original system components.

Case Studies of Tipping Points

System Tipping Point Trigger New State Reversibility
Coral reef Chronic thermal stress (repeated bleaching) Algal-dominated reef Very difficult β€” recovery takes decades if possible
Lake eutrophication Nutrient loading exceeds absorption capacity Hypoxic, algae-dominated lake Difficult β€” requires sustained nutrient reduction over years
Savannification of Amazon Deforestation + drought reduces rainfall below threshold Savanna / grassland Largely irreversible at human timescales
Arctic sea ice Ice-albedo feedback amplifies warming Ice-free Arctic summers Possible if emissions reduced, but uncertain timescale
Groundwater depletion Extraction exceeds recharge rate for extended period Compaction, land subsidence Permanent β€” aquifer structure is physically destroyed
πŸ“Œ The Concept of Hysteresis: A system may require a much larger effort to return to its original state than the effort that pushed it past the tipping point. This is called hysteresis. For example, clearing a lake of algae requires far less nutrient input than was needed to create the algal bloom.
1.2.17

Social-Ecological Systems

A social-ecological system (SES) is a system that integrates human (social) and natural (ecological) components. Most environmental issues occur within social-ecological systems.

Key Understanding: You cannot understand environmental issues by studying ecology alone OR sociology alone. Social-ecological systems require integrated analysis that considers both human behaviour and ecological processes.

Example: Coastal Fisheries

🐟 Fish stocks
(Ecological component)
⟷
πŸ‘¨β€πŸŒΎ Fishing communities
(Social component)
⟷
πŸ“œ Regulations & markets
(Institutional component)
Component Type Elements Interactions
Ecological Fish populations, marine habitats, ocean currents, food webs Spawning cycles, trophic cascades, habitat degradation
Social Fishing communities, cultural traditions, livelihoods, food security Economic dependence, traditional knowledge, overfishing pressure
Institutional Fishing quotas, marine protected areas, trade agreements, subsidies Regulation effectiveness, enforcement, political will

Overfishing is not just a biological problem β€” it emerges from the interaction of economic incentives, cultural practices, governance structures, and ecological dynamics. Solutions must address all these dimensions.

βœ… Exam Tip: In essay questions, framing your analysis within a social-ecological system demonstrates sophisticated understanding. Explicitly identify the social and ecological components and their interactions.
1.2.18 β€” HL Only

Applying Systems Thinking to Real-World Issues

Systems thinking can be applied to real-world environmental issues using systems diagrams that identify components, flows, and feedback loops.

Case Study: Climate Change

🏭 Fossil fuel combustion
β†’
☁️ Increased atmospheric COβ‚‚
β†’
🌑️ Enhanced greenhouse effect
β†’
πŸ“ˆ Global temperature rise

Key Feedback Loops in Climate Change

Feedback Type Mechanism
Ice-albedo Positive Warming β†’ ice loss β†’ darker surface β†’ more absorption β†’ more warming
Water vapour Positive Warming β†’ more evaporation β†’ more water vapour (greenhouse gas) β†’ more warming
Cloud formation Negative (uncertain) Warming β†’ more clouds β†’ more reflection β†’ cooling
Plant growth Negative Higher COβ‚‚ β†’ increased photosynthesis β†’ more COβ‚‚ absorbed

Case Study: Deforestation in the Amazon

Component Role in System
Forest Carbon sink, water recycler, biodiversity reservoir
Agriculture (cattle/soy) Economic driver of deforestation
Rainfall Dependent on forest transpiration (50% of Amazon rainfall is recycled by the forest)
Fire Both consequence and cause of deforestation (positive feedback)
Local communities Dependent on forest for livelihoods; affected by land-use change
Global market Drives demand for beef and soy; creates economic incentive for deforestation
πŸͺ“ Deforestation
β†’
🌧️ Less transpiration β†’ less rainfall
β†’
πŸ”₯ Drier conditions β†’ more fire
β†’
πŸͺ“ More deforestation (positive feedback)

Case Study: Integrated Water Resource Management

System Component Interactions
Groundwater Stock depleted by extraction; recharged by rainfall infiltration
Agriculture Major consumer; returns nutrients and pesticides to water
Urban areas Impervious surfaces increase runoff; wastewater treatment plants
Ecosystems Depend on environmental flows; provide water purification services
Policy Water allocation, quality standards, pricing mechanisms
Key Understanding: When applying systems thinking to real-world issues, always: (1) identify components and their roles, (2) map flows of energy/matter, (3) identify feedback loops (positive and negative), (4) consider boundaries and scale, and (5) evaluate resilience and tipping points.
βœ… Exam Tip: For HL Paper 3 questions, you may be asked to draw or interpret a systems diagram. Practise drawing diagrams that include: components (boxes), flows (arrows), feedback loops (circular arrows), and labels for positive (+) or negative (βˆ’) feedback.
Glossary

Key Terms & Definitions

Term Definition
System A collection of components that interact with each other and their environment to form a functional whole.
Environmental system A system in which natural components (biotic and abiotic) interact with each other and with human activities.
Emergent property A property that arises from the interactions of components within a system but does not exist in any individual component.
Open system A system that exchanges both energy and matter with its surroundings. Most natural systems are open.
Closed system A system that exchanges energy but not matter with its surroundings. Earth is approximately a closed system with respect to matter.
Isolated system A system that exchanges neither energy nor matter with its surroundings. Theoretical only β€” no true isolated systems exist.
Model A representation of a system used to understand, predict, or manage its behaviour. Can be physical, conceptual, mathematical, or computer-based.
Systems thinking An approach to understanding phenomena by examining how components interact within a system to produce emergent properties.
Input Energy, matter, or information that enters a system from outside its boundary.
Output Energy, matter, or information that leaves a system through its boundary.
Feedback A process in which the output of a system feeds back as an input, modifying the system's subsequent behaviour.
Negative feedback Feedback that opposes a change, tending to stabilise a system and maintain it near equilibrium.
Positive feedback Feedback that amplifies a change, tending to destabilise a system and potentially push it past a tipping point.
Stock An accumulation of matter, energy, or information within a system at a given point in time.
Flow The rate of change of a stock β€” the movement of matter, energy, or information into or out of a stock.
Resilience The ability of a system to absorb disturbance and recover to its original state.
Tipping point A threshold beyond which a system undergoes a significant, often irreversible shift to a new state.
Social-ecological system A system that integrates human (social) and natural (ecological) components, recognising their interdependence.
Boundary The conceptual or physical limit that defines what is inside and outside a system.
Hierarchical Organised in levels, with smaller subsystems nested within larger systems. Each level has its own emergent properties.
Dynamic equilibrium A state in which the stocks of a system remain constant because inflows equal outflows, despite ongoing processes.
Hysteresis The phenomenon where the effort required to reverse a system shift is greater than the effort that caused it.
Reductionism An approach that studies a system by breaking it into its individual components (contrast: systems thinking).
Exam Tips

Command Terms & Common Patterns

Command Terms in 1.2

Command Term What to Do Example
Define Give the meaning of a term precisely "Define the term emergent property."
Describe Give an account of features "Describe a negative feedback loop in an ecosystem."
Explain Give reasons or account for how/why something occurs "Explain how positive feedback can lead to a tipping point."
Outline Briefly describe or give main features "Outline the factors that affect system resilience."
Distinguish Identify differences between two or more items "Distinguish between open and closed systems."
Compare Identify similarities AND differences "Compare positive and negative feedback."
Evaluate Make judgements using evidence and criteria "Evaluate the effectiveness of systems models in predicting environmental change."
Apply Use knowledge in a new context "Apply systems thinking to analyse a case study of your choice."

Common Question Patterns

Question Type Strategy
Draw/label a systems diagram Include: components (boxes), flows (arrows), feedback loops (circular arrows), boundary. Label clearly. Use a case study you know well.
Identify feedback types Read the scenario carefully. If the process opposes change β†’ negative. If it amplifies change β†’ positive. Always explain WHY it is positive/negative.
Explain resilience Define resilience. Identify at least TWO factors (biodiversity, connectivity, redundancy). Apply to the specific case study. Mention tipping points if relevant.
Apply systems thinking Identify components. Map interactions. Identify feedback loops. Discuss emergent properties. Mention boundaries and scale. Consider social-ecological dimensions.
Evaluate a model Identify what the model shows (strength). Identify what it simplifies or misses (limitation). Discuss whether it is appropriate for the question being asked.
Stocks and flows analysis Identify the stock. List all inflows and outflows. Determine if inflows = outflows (equilibrium) or not (change). Discuss what would happen if a flow is altered.

Sample 9-Mark Essay Structure

  1. Introduction β€” Define key terms. State the systems thinking approach you will use.
  2. Body Paragraph 1 β€” Identify system components and their interactions. Draw reference to a systems diagram.
  3. Body Paragraph 2 β€” Identify feedback loops (positive and negative). Explain how they shape system behaviour.
  4. Body Paragraph 3 β€” Discuss resilience, tipping points, and emergent properties in the context of your case study.
  5. Body Paragraph 4 (HL) β€” Apply systems thinking to analyse a management strategy or policy intervention.
  6. Conclusion β€” Summarise key insights. Evaluate the effectiveness of the systems thinking approach for understanding the issue.
βœ… Final Advice:
  • Always use specific examples β€” abstract answers score poorly.
  • Practise drawing systems diagrams by hand β€” this is a frequently assessed skill.
  • For negative/positive feedback, always explain the direction of the loop and the outcome.
  • The phrase "emergent property" must appear in almost every systems-related response.
  • In HL, explicitly reference the concept of social-ecological systems when relevant.