ENVR 200: Systems Thinking and the Global Environment

Vocabulary flashcards covering core systems thinking concepts, system components, feedback dynamics, equilibrium states, and environmental applications.

System

A set of interacting or interdependent components forming an integrated whole that maintains its existence through mutual interaction within a defined boundary.

Elements (Components)

The entities, state variables, or reservoirs (matter or energy) that make up a system and represent where quantities of matter or energy reside for a period of time.

Linkages (Couplings)

The relationships, connections, flows, or channels that link components in a system through transfers of matter, energy, or conceptual interactions.

Boundaries

The defined limits marking where a system ends, which can be easily defined by natural barriers or chosen arbitrarily to make system analysis manageable.

Open System

A system possessing a porous boundary that allows energy and matter inputs and outputs to enter and exit the system.

Closed System

A system possessing a non-porous boundary that prevents matter from crossing into or out of the system.

Simple System

A system characterized by few, linear relationships that yield consistently predictable outcomes.

Complicated System

A system containing many branching, linear relationships with few loops, yielding predictable outcomes when carefully analyzed.

Complex System

A system containing many non-linear, branching relationships and feedback loops that exhibits resilience, self-organization, emergence, and unexpected outcomes.

Qualitative Systems

System models that represent linked material or immaterial concepts, interacting social groups, institutions, policies, or circumstances.

Quantitative Systems

System models that track measurable quantities of components (such as mass or energy) and describe transfers using mathematical formulations.

Element Dynamics Formula

The mathematical equation expressing the rate of change in an element's reservoir over time: $\frac{\Delta E}{\Delta t} = I - O$, where $I$ is total input rate and $O$ is total output rate.

Steady-State System

A system condition where total inputs equal total outputs ($I = O$) across elements, causing the quantity in reservoirs to remain constant over time ($\frac{\Delta E}{\Delta t} = 0$).

Transient System

A system condition where total inputs do not equal total outputs ($I \neq O$), causing the quantity in a reservoir to increase or decrease over time ($\frac{\Delta E}{\Delta t} \neq 0$).

Mean Residence Time

The average duration matter or energy remains inside a system reservoir, calculated as reservoir quantity divided by total output rate ($E / O$).

Positive Coupling

A linkage between two elements where a change in the first element causes a change of the same sign in the second element.

Negative Coupling

A linkage between two elements where a change in the first element causes a change of the opposite sign in the second element.

Positive Feedback Loop

A closed sequence of couplings containing an even number of negative couplings (or zero) that amplifies initial changes in a system, creating virtuous or vicious cycles.

Negative Feedback Loop

A closed sequence of couplings containing an odd number of negative couplings that diminishes initial changes in a system, acting as the primary agent of stability.

Equilibrium States

The dynamic balance conditions of a system classified into stable equilibrium, unstable equilibrium, and neutral equilibrium based on how the system responds to perturbations.

Stable Equilibrium

A system state where negative feedback loops dominate, causing the system to return toward its original state following a disturbance.

Unstable Equilibrium

A system state where positive feedback loops dominate, causing small perturbations to push the system progressively further away from its initial state.

Tipping Point

A critical threshold of unstable equilibrium where positive feedbacks overcome negative feedbacks, triggering a rapid, self-sustaining transition into a different stable state.

Systems Thinking

A problem-framing approach that analyzes system behavior by investigating the structure of feedback loops and interrelationships rather than linear, isolated cause-and-effect chains.

Carbfix

An environmental technology developed in Iceland that dissolves captured carbon dioxide in water and injects it into basaltic rock to turn it into solid carbonate minerals within $2\,\text{years}$.