TOPIC 1: Foundation

1.1 Perspectives

1.2 Systems

1.3 Sustainability

Guiding Question

• How can the systems approach be used to model environmental issues at different levels of complexity and scale?

1.2 SL/HL Knowledge & Understandings (5hrs)

1. Systems are sets of interacting or interdependent components.
2. A systems approach is a holistic way of visualizing a complex set of interactions, and it can be applied to ecological or societal situations.
3. In system diagrams, storages are usually represented as rectangular boxes and flows as arrows, with the direction of each arrow indicating the direction of each flow.
4. Flows are processes that may be either transfers or transformations.
5. Systems can be open or closed.
6. The Earth is a single integrated system encompassing the biosphere, the hydrosphere, the cryosphere, the geosphere, the atmosphere and the anthroposphere.
7. The concept of a system can be applied at a range of scales.
8. Negative feedback loops occur when the output of a process inhibits or reverses the operation of the same process in such a way as to reduce change. They are stabilizing as they counteract deviation.*
9. As an open system, an ecosystem will normally exist in a stable equilibrium, either in a steady-state equilibrium or in one developing over time (for example, succession), and will be maintained by stabilizing negative feedback loops.
10. Positive feedback loops occur when a disturbance leads to an amplification of that disturbance, destabilizing the system and driving it away from its equilibrium.*
11. Positive feedback loops will tend to drive the system towards a tipping point.
12. Tipping points can exist within a system where a small alteration in one component can produce large overall changes, resulting in a shift in equilibrium.
13. A model is a simplified representation of reality; it can be used to understand how a system works and to predict how it will respond to change.
14. Simplification of a model involves approximation and, therefore, loss of accuracy.
15. Interactions between components in systems can generate emergent properties.
16. The resilience of a system, ecological or social, refers to its tendency to avoid tipping points and maintain stability.
17. Diversity and the size of storages within systems can contribute to their resilience and affect their speed of response to change (time lags).
18. Humans can affect the resilience of systems through reducing these storages and diversity.

Expected & Ancillary Vocabulary

• Biosphere
• Closed / Open system
• Flow
• Transfer
• Transformation
• Model
• Store
• Sink
• Boundary
• Emergent
• Holism
• ​

• Negative / Positive feedback
• Resilience
• Equilibria
• Steady-state equilibrium
• Time lag
• Tipping point
• Reservoir
• Synergy
• Biodiversity
• Threshold
• Reductionism
• Determinism
• Terrestrial / Aquatic
• ​

1.2.13 Models

… “A simplified representation of structure, relationships or processes.” Can include a variety of media forms:

• Diagram
• Mathematical equation
• Physical model
• Computer model
• Simulation
• Text description

1.2.14 Models: Strengths & Limitations

Strengths:

• Illustrate complex systems in simplified ways
• When inputs changed, outputs measured without waiting (millions of yrs)
• Allow for prediction or projection of events
• Results easily communicated to non-specialists for action or decision-making
• Transfer understanding from one area or scale to another (atoms, carbon cycle)

Limitations:

• Accuracy (e.g., climate models have tens of variables to calculate)
• Rely upon creators’ expertise
• What is important? What is not?
• What happens when knowledge/values change?
• Outcomes can be concluded differently
• Different models may exhibit different results with same inputs
• Chaos theory & determinism
• May prevent updates to worldviews if too attached to a model’s results
• Milankovitch cycles

1.2.14 Behavior-time: Sustainable Development Models

1.2.1_4 What is this?

Axle, bar ends, bar plugs/end caps, basket, bearing, bell, belt-drive, brake cable, bottle cage, bottom bracket, brake, coaster brakes, brake lever, braze-on, cable guide, cable, cartridge bearing, cassette, chain, chainguard, chainring, chainstay, chain tensor, chaintug, cluster, cogset, cone, cranket, cotter, coupler, cup, cyclometer, derailleur hanger, derailleur, down tube, dropout, dustcap, dynamo, eyelet, electronic gear-shifting system, fairing, fender/mudguard, ferrule, fork, fork end, frame, freehub, freewheel, gusset, hanger, handlebar, handlebar plug, handlebar tape, head badge, head tube, headset, hood, hub, hub dynamo, hub gear, indicator, inner tube, jockey wheel, kickstand, Lawyer lips, locknut, lockring, lug, luggage carrier, master link, nipple, pannier, pedal, peg, portage strap, quick release, rack, reflector, removable training wheels, rim, rotor, safety levers, saddle/seat, seat rails, seat lug, seat tube, seat bag, seatpost, seatstay, shaft-drive, shifter, shock absorber, side-view mirror, skirt guard, spindle, spoke, steering tube, stem, tire, toe clips, top tube, valve system, wheel, wingnut.

1.2.1_4 A Two-wheel System

1.2.1_4 Systems & Components

Boundary?

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Components?

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Processes?

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Feedback?

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Synergy?

1.2.1_4 Systems & Components

Boundary - imaginary line between inside/outside the system

Components [BOXES] - parts that are storages, sinks, reservoirs, and stocks

Processes [ARROWS] - flows of matter &/or energy, (inputs/outputs), transfers, transformations, and reactions (e.g., photosynthesis & respiration)

Feedback - outputs that become inputs and influence equilibria

Synergy - emergent behavior

1.2.1_4 Synergy & Emergent Behavior

Emergence... “The whole is greater than the sum of its parts.”

Properties cannot be reliably predicted through reductionism and models

• Human elements ~$20 (2023 prices)
• Human organs sold ~ $550 000 (2024 prices)
• Human organs bought ~ $45 million (U.S.)
• A human?
• Life insurance
• Worker’s compensation
• Lost wages (disability insurance)
• NPR 2020 Podcast: Lives vs. the Economy (23min)
• Holism - parts of a whole are intimately interconnected (mental states, language, ecology)

1.2.4 Flows →

Transfers…

• Matter or energy
• Particles like carbon & other geochemical cycles, gases, e^-
• Light, sound, heat
• Change of location
• Advection, convection, current, thermohaline circulation, conduction
• Distribute resources in an environment
• Nutrients, water, gases, deposition, bacteria, dispersal

Transformations…

• Matter or energy
• Particles like carbon & other geochemical cycles, gases, e^-
• Light, sound, heat, nuclear
• Change of state, phase or chemistry
• Evapotranspiration, sublimation, enthalpy, heat of fusion, nuclear
• NO_x, SO_x, CO_x, reduction-oxidation
• Maintain balance (reuse & recycle) in an environment
• Photosynthesis & respiration

1.2.5 Open, Closed & Isolated Systems

Using the diagram at left, suggest a definition for each of the following types of systems:

• Open -

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• Closed -

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• Isolated -

Real World - Biosphere II

• Terrarium built in Arizona, USA in late 1980’s
• Simulation of ecological systems, biogeochemical cycles and interaction of 3 000 different species (including 8 humans)
• September 26, 1991 experiment began (meant for 2 yrs)
• Low O₂ levels after 1 year → pumping & CO₂ scrubbing (without disclosure)
• NOW (SciAm 2021_10)

VIDEO Documentary Short

1.2.6 Integrated Earth (My Name is Lyla June - Indigenous Knowledge)

1.2.5 & HLc.1. R. Buckminster Fuller

American architect, designer, systems theorist, author, futurist, inventor (1895-1983)

Most documented human ever? Dymaxion Chronofile

• Big ideas:
• Geodesic dome
• Synergetics
• Dymaxion World
• World Game

1.2.7 TOK & Scaling of Systems

A system is the first subdivision of Universe. It divides all the Universe into 6 parts:

1^st - all the universal events occurring geometrically outside the system;

2^nd - all the universal events occurring geometrically inside the system;

3^rd - all the universal events occurring non-simultaneously, remotely, and unrelatedly prior to the system events;

4^th - the Universe events occurring non-simultaneously, remotely, and unrelatedly subsequent to the system events;

5^th - all the geometrically arrayed set of events constituting the system itself;

6^th - all the Universe events occurring synchronously and or coincidentally to and with the systematic set of events uniquely

- According to R. Buckminster Fuller

1.2.7 (2.1.1) Scaling of Systems - Reductionistic & Holistic

Micro

• Quanta
• Atoms
• Amino Acids
• Eukaryotic cells
• Tank bromeliads
• ​
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Ecosystem

• Biotic & abiotic
• Inputs of nutrients, water, energy
• Feeding relationships
• Trophic levels
• Organisms (Im/E)migration
• Boundary (artificial or natural)
• Feedback mechanisms
• ​
• ​

Global

• Biosphere
• Atmosphere
• Hydrosphere
• Cryosphere
• Geosphere
• Pedosphere
• Lithosphere
• ​
• ​

1.2.16 (6.2.13) Global Systems

↑ Click for full 2023 Report ↑

1.2.16 (6.2.13) Global Tipping Points

Global Systems Institute @ the University of Exeter (host), the Potsdam Institute for Climate Impact Research & the Max Planck Institute for Geoanthropology will co-host the Global Tipping Points Conference in July 2025.

Governors:

1.2.16 (2.1.20) Ecosystems

BIG IDEA FOR HEALTHY ECOSYSTEMS

Matter cycles within

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Energy flows through

1.2.8_11 Equilibria → More Than One Type

…the condition of a system when all competing components, storages and processes are balanced.

Static Equilibrium - all components of a system are at rest and net forces are all zero.

Steady-State Equilibrium - average condition of the system is unchanged, but often has deviations above or below the average (equilibrium point)

Dynamic Equilibrium - a state of balance between reversible processes (reactants & products)

Stable Equilibrium - a system returns to its original equilibrium after a disturbance

Unstable Equilibrium - ?

1.2.8_11 Which is Which Equilibria?

1.2.8_11 Feedback (Loops)

Outputs becoming inputs that influence equilibria

Two kinds:

Negative Feedback - feedback causing a system to return to or maintain (steady-state) equilibrium

Positive Feedback - feedback causing increased change to a system’s equilibrium

1.2.11 (6.2.7) Real World Climate 1. State the feedback type, then outline why. [3ea]

1. As CO2 levels in the atmosphere rise, the temperature of Earth rises. As the Earth warms the rate of photosynthesis in plants increases, more CO2 is therefore removed from the atmosphere by plants, reducing the greenhouse effect and reducing global temperatures.
2. As the Earth warms, ice cover melts, exposing soil or water. Albedo decreases. More energy is absorbed by the Earth's surface. Global temperatures rise, more ice melts.
3. As the Earth warms, upper layers of permafrost melt, producing waterlogged soil above frozen ground. Methane gas is released into the environment. The greenhouse effect is enhanced. The Earth warms, melting more permafrost.
4. As the Earth warms, increased evaporation produces more clouds. Clouds increase albedo, reflecting more light away from the Earth. The temperature falls, rates of evaporation fall.
5. As the Earth warms, organic matter in soil decomposes faster, more CO2 is released, the enhanced greenhouse effect occurs, the Earth warms and decomposition rates increase.
6. As the Earth warms, evaporation increases. Snowfall at high latitudes increases. Icecaps enlarge. More energy is reflected by increased albedo of ice cover. The Earth cools, rate of evaporation fall.
7. As the Earth warms, polar ice caps melt, releasing large numbers of icebergs into oceans. Warm ocean currents (Gulf Stream) are disrupted by additional freshwater input. Reduced transfer of energy to the poles reduces temperature at high latitudes. Ice sheets reform and icebergs retreat. Warm currents are reestablished.

- from Rutherford © 2017 pg. 37 (82)

1.2.12 Tipping Points

- a critical threshold after which even a small change can be catastrophic to the system…

- Davis & Nagle

1.2.12 Tipping Points

Examples of ecosystems affected by tipping points:

• Loss of a keystone/ umbrella species
• Coral bleaching
• Eutrophication (Subtopic 4.4)

1.2.16 Resilience

…of an ecological or social system) is a system’s tendency to return to its steady-state equilibrium after a disturbance.

…a system’s response to a disturbance.

Greater resilience = greater stability

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Wikipedia™ on Ecological Resilience & Sustainable Development:

“Resilience has been defined (by Canadian ecologist C.S. Holling) in two ways in ecological literature:

1. time required for an ecosystem to return to an equilibrium or steady-state following a perturbation → ‘engineering resilience’.
2. the capacity of a system to absorb disturbance & reorganize while undergoing change so as to still retain essentially the same function, structure, identity, & feedbacks."

1.2.16 Resilience & System Stability

Real World Physics - Engineering Resilience

• Taipei 101-Wind Loading

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Galloping Gertie

1.2.17 Diversity & Stability

(Bio)diversity - (TOPICS 2 & 3)

There are three kinds (in reverse order of “importance”…):

1. Genetic
2. Species
3. Habitat

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A closer look in order of importance to stability & sustainability…

1.2.17 Habitat Diversity

Scaling from backyards to regions to interconnected transnational networks

1.2.17 Species Diversity

2. Identify when mammals appeared on Earth. [1]
3. State the classification of organism that has existed on Earth since life began. [1]
4. Suggest two reasons for the classification of organism that had the greatest impact on Earth’s geologic history. [2]

1.2.17 Genetic Diversity

Maize’s Genetic Diversity

1.2.18 (8.2.7) Human Terrestrial Influences

Humans affect resilience through reducing storages

1.2.18 Storage & Scale of Influences

1.2.17_18 Human Influence on Aquatic Biodiversity