Preview
IB DP ESS — Topic 1: Foundations | SL & HL | Paper 1 & Paper 2A/2B
🎯 Learning Intentions By the end of this note, you will be able to:
- Define open systems, closed systems, and isolated systems using IB-aligned ESS terminology, distinguishing between flows of matter and energy.
- Explain how inputs, outputs, storages, and flows operate within environmental systems, and how these components determine system behaviour.
- Describe Earth as a system, identifying it as approximately closed with respect to matter but open with respect to energy.
- Distinguish between positive and negative feedback mechanisms and explain their roles in maintaining or destabilising environmental systems.
- Explain the concept of steady state and dynamic equilibrium in environmental systems, with reference to named real-world examples.
- Analyse how human activities alter system inputs, outputs, and feedback loops, using ESS analysis parameters including scale, sustainability, and trade-offs.
- Evaluate the significance of Earth's system boundaries in the context of global environmental change and resource limits.
- Discuss contrasting worldviews (ecocentric, technocentric, anthropocentric) in relation to how humans perceive and interact with Earth as a system.
Real-World Context & Relevance
In September 2023, the journal Science Advances published a landmark update to the Planetary Boundaries framework, concluding that six of nine Earth-system boundaries had been transgressed — including climate change, biosphere integrity, freshwater change, and novel entities such as synthetic chemicals. The researchers, led by Johan Rockström at the Stockholm Resilience Centre, described Earth as a single, interconnected system with finite thresholds beyond which the conditions that have supported human civilisation for 10,000 years may no longer hold. This is not abstract theory: it is a direct consequence of treating Earth's systems as if they were open and unlimited, when in reality the planet operates as a largely closed material system with strict physical constraints on how much matter can cycle and how much waste can be absorbed.
Closer to home, consider the fate of the Aral Sea in Central Asia — once the world's fourth-largest lake. Soviet-era irrigation projects diverted the Amu Darya and Syr Darya rivers to grow cotton in the desert, fundamentally altering the water inputs to the lake system. By 2007, the Aral Sea had shrunk to roughly 10% of its original volume, leaving behind salt flats, abandoned fishing villages, and a regional climate that had become hotter and drier. This collapse illustrates what happens when humans redirect the flows within an environmental system without understanding the feedback loops that maintain its equilibrium. Understanding systems — their boundaries, their flows, their feedbacks — is not merely academic; it is the foundation of every environmental decision we make.
🌍 Why This Matters Every environmental problem — from climate change to biodiversity loss to freshwater scarcity — can be understood as a disruption to the flows, storages, and feedbacks within Earth's interconnected systems. Systems thinking is the analytical lens that makes ESS coherent: once you understand how systems work, you can diagnose what is going wrong and evaluate what interventions might restore balance.
Core Concepts & Definitions
Before we can analyse any environmental problem — whether it is the acidification of the ocean, the collapse of a fishery, or the warming of the atmosphere — we need a shared language for describing how things are connected and how