Foundations of environmental systems and societies
Domain 1 examines how environmental systems are modelled and how societies value them. The exam tests systems diagrams, feedback, resilience, sustainability and environmental value systems (EVS), often through short data-response items and a case study.
Systems rules
- A system has storages, flows, transfers (same form, e.g. water moving) and transformations (new form, e.g. evaporation).
- Negative feedback stabilises a system; positive feedback amplifies change and can cross a tipping point.
- Resilience is the capacity to absorb disturbance and retain function; it is not the same as resistance.
- Models simplify reality, so they carry uncertainty; evaluate assumptions, scale and boundaries.
EVS continuum
Ecocentric values prioritise nature's intrinsic value; anthropocentric values prioritise human welfare; technocentric values trust technology to solve limits. Real viewpoints mix these.
Worked example
A lake receives phosphorus from farmland. More phosphorus leads to more algae, more decomposition, lower oxygen and fish deaths. Decomposing algae release more phosphorus from sediment, so the loop reinforces itself. That is positive feedback. If wetland plants instead took up phosphorus, that uptake would be negative feedback. Reasoning: identify the variable that changes, the direction of change, and whether the loop opposes or amplifies it. The first loop can cross a tipping point to a turbid, low-oxygen state; the second builds resilience.
Traps
- Calling feedback positive when it is beneficial; in systems terms, positive means amplifying.
- Mixing transfer and transformation.
- Treating an EVS as a single political label rather than a spectrum with trade-offs.
- Assuming a model predicts exactly; credit comes from evaluating limitations.