IB DP Environmental Systems and Societies Topic 1: Foundations -- Revision Notes

Topic 1 – Foundations is deliberately the first thing every ESS student studies, and, as the full syllabus guide explains, its three concepts are explicitly “revisited throughout the course” rather than assessed once and set aside. These notes go deeper into the three sub-topics than the syllabus guide’s overview, alongside the subject overview and assessment revision notes already on the site.

1.1 Perspectives (3 hours)

Differing individual and collective worldviews on environmental issues. The syllabus’s own key term here is the environmental value system (EVS) – a particular world view or paradigm that shapes the way an individual or group perceives and evaluates environmental issues, influenced by cultural, religious, economic and socio-political context. Revise the three broad EVS categories used across the course: ecocentrism (nature-centred, valuing the environment for its own sake), anthropocentrism (human-centred, managing the environment for humanity’s benefit), and technocentrism (a belief that technology and human ingenuity can solve environmental problems). A strong exam answer applies an EVS category to a specific described scenario or stakeholder, rather than only defining the three terms in the abstract.

1.2 Systems (5 hours)

Systems theory as a tool for understanding environmental structures and processes. Key vocabulary to know precisely: a system is an assemblage of interrelated parts that interact in a coherent way; inputs and outputs are energy or matter crossing the system boundary; a feedback loop is a mechanism where a change in a system’s output affects its own input. Distinguish negative feedback (counteracts and stabilises a change, moving the system back toward equilibrium) from positive feedback (amplifies a change, pushing the system further from its original state) – confusing the two is one of the most common ESS exam errors, since “negative” here means stabilising, not “bad”. Also revise the distinction between open systems (exchange both energy and matter with their surroundings), closed systems (exchange only energy, not matter) and isolated systems (exchange neither) – most ecosystems are treated as open systems in this course.

1.3 Sustainability (8 hours)

Resource management and the idea of sustainability as central to the whole course – the largest of Topic 1’s three sub-topics by teaching hours. Core vocabulary: natural capital (natural resources that provide goods and services of value to humans), natural income (the yield obtainable from natural capital without depleting it), and sustainability itself, generally framed as meeting present needs without compromising the ability of future generations to meet their own. Revise the distinction between renewable natural capital (can be replenished, e.g. forests, if harvested within its natural income) and non-renewable natural capital (finite, e.g. fossil fuels, where any use is by definition a depletion). This sub-topic also introduces environmental indicators used to measure sustainability, such as the ecological footprint – the area of land and water required to sustainably provide all resources at the rate they are being consumed, and to assimilate the associated waste.

Why Topic 1 gets disproportionate revision value

Because the specification explicitly revisits perspectives, systems and sustainability throughout every later topic, a student who has genuinely internalised this vocabulary can apply it to unfamiliar content on water, land, atmosphere or resources without having studied that content in the same depth as a student who has not built this foundation. Concretely: any Topic 4-8 question can, in principle, ask you to identify the EVS underlying a described policy position, model a described environmental process as a system with named inputs/outputs/feedback loops, or evaluate whether a described resource-use pattern is within its natural income. Treating Topic 1 as a short warm-up rather than a recurring toolkit is the single most common reason for descriptive, rather than analytical, ESS exam answers.

Common exam pitfalls

• Defining “negative feedback” as bad and “positive feedback” as good – both terms describe the direction of the effect on the system (stabilising vs amplifying), not a value judgement.
• Confusing natural capital with natural income – capital is the stock, income is the sustainable yield from that stock.
• Applying an EVS label without evidence from the scenario – always justify which specific words or actions in a case study indicate ecocentrism, anthropocentrism or technocentrism.
• Treating “sustainable” as a simple yes/no label rather than a threshold – a resource is being used sustainably only while consumption stays within its natural income; the same resource can move between sustainable and unsustainable use over time.

Self-test

1. Define environmental value system (EVS) and name its three broad categories.
2. What is the difference between negative feedback and positive feedback in a system?
3. Distinguish an open system from a closed system.
4. Define natural capital and natural income, and explain how they differ.
5. What does the ecological footprint measure?
6. Explain, with one example, why Topic 1 vocabulary is expected to reappear in answers on later topics such as Water or Atmosphere and climate change.

Answers: 1. A particular world view or paradigm shaping how an individual or group perceives and evaluates environmental issues; ecocentrism, anthropocentrism and technocentrism. 2. Negative feedback counteracts a change and stabilises the system back toward equilibrium; positive feedback amplifies a change, pushing the system further from its original state. 3. An open system exchanges both energy and matter with its surroundings; a closed system exchanges only energy, not matter. 4. Natural capital is the stock of natural resources providing goods and services of value; natural income is the sustainable yield obtainable from that capital without depleting it – capital is the stock, income is the flow. 5. The area of land and water required to sustainably provide all the resources a population consumes, and to assimilate the waste it produces, at the rate it is consuming and producing. 6. Any well-justified example, e.g.: a question on freshwater over-extraction can be analysed as a system with defined inputs/outputs and a feedback loop, and evaluated against whether extraction is exceeding the resource’s natural income – both Topic 1 concepts applied directly to Topic 4 content.

Official syllabus

International Baccalaureate Organization, Diploma Programme Subject Brief – Environmental Systems and Societies, first assessment 2026, https://ibo.org/globalassets/new-structure/university-admission/pdfs/environmental-systems-and-societies-subject-brief-en.pdf, fetched and verified in full 2026-09-02 – the same source already cited by the full syllabus guide, which first reproduced Topic 1’s three sub-topics and their teaching hours from it.