IB Environmental Systems: Foundations of Environmental Systems Revision

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Is energy recycled within an ecosystem?

Foundations of Environmental Systems is a core part of IB Environmental Systems. Revise the key concepts and common mistakes below, then lock them in with the free games.

Key concepts

ModellingPredicting environmental change.

SystemsA set of interacting components: storages hold matter or energy, and flows move it in, out and between them as transfers or transformations.

Open, closed, isolated systemsOpen systems exchange energy and matter with their surroundings; closed systems exchange energy only; isolated systems exchange neither.

Environmental value systemA worldview, shaped by culture, education and experience, that frames how a person or society perceives and evaluates environmental issues.

Ecocentric to technocentric spectrumEcocentrics put nature first, anthropocentrics manage the environment for human needs, and technocentrics trust technology to solve environmental problems.

Thermodynamics in ecosystemsEnergy is conserved (first law) but every transformation loses some as heat (second law), so energy flows through ecosystems and is not recycled.

Steady-state equilibriumInputs and outputs balance, so a system fluctuates around a constant average and returns to it after small disturbances.

Negative and positive feedbackNegative feedback counteracts change and stabilises a system; positive feedback amplifies change, pushing a system away from equilibrium.

Tipping pointA threshold beyond which a small further change triggers a large, often irreversible shift of a system to a new equilibrium.

SustainabilityUsing resources at a rate that allows natural regeneration, meeting present needs without compromising future generations' ability to meet theirs.

What your exam board covers

Where Foundations of Environmental Systems sits in each exam board's specification. Tap a board to see what it lists.

HLTopic 1 — Foundation

1.1 Perspectives
1.2 Systems
1.3 Sustainability

Source: IB Diploma Environmental Systems and Societies guide, accessed 23 June 2026.

SLTopic 1 — Foundation

1.1 Perspectives
1.2 Systems
1.3 Sustainability

Source: IB Diploma Environmental Systems and Societies guide, accessed 23 June 2026.

Learn Foundations of Environmental Systems step by step

Free interactive mini-lessons: short screens, worked examples and quick checks. Pick your exam board:

Common mistakes to avoid

Questions where students often pick the tempting wrong answer — make sure you know the right one:

Is energy recycled within an ecosystem?✗ Yes, energy cycles round endlessly. ✓ No — energy flows through and is lost as heat; nutrients are recycled.

Practise Foundations of Environmental Systems — free games

Test yourself with these quick revision games for this topic:

▶ Two Truths, One Lie ▶ Reveal Race ▶ Connections Grid ▶ Falling Words ▶ Word Web

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Foundations of Environmental Systems

Key concepts

What your exam board covers

Common mistakes to avoid

Practise Foundations of Environmental Systems — free games

More IB Environmental Systems topics