IB ESS SL study plan

Define and correctly apply the core systems vocabulary from Domain 1: open, closed and isolated systems, storages, flows, transfers, transformations, positive and negative feedback, tipping points and resilience.

Construct and annotate a systems diagram for at least two real examples (for example a lake receiving nutrient runoff, or a forest after fire) showing storages, flows and feedback loops.

Distinguish the four spheres (atmosphere, biosphere, hydrosphere, lithosphere) and explain, with one worked example each, how a change in one sphere propagates into another.

Explain the difference between models and reality, and evaluate the strengths and limitations of at least two types of environmental model (for example a climate model and a population-growth model).

Write a one-paragraph answer to a command term such as 'explain' and another to 'evaluate', checking that the depth of response matches the command term.

Describe and compare the processes of photosynthesis, respiration and decomposition in terms of energy flow and carbon transfer, and place them correctly on a food chain.

Construct a quantitative food chain or food web from given data and calculate the energy or biomass lost at each trophic level, then express the transfer efficiency as a percentage.

Draw and interpret a pyramid of numbers, a pyramid of biomass and a pyramid of productivity, and explain one situation in which each can appear inverted.

Explain primary and secondary succession, including the role of pioneer species, climax communities, and the effect of a named human intervention on the successional pathway.

Apply the concepts of gross and net productivity to a named ecosystem and explain how human activity could change the net figure.

Explain how abiotic factors (light, temperature, water, soil pH, salinity) and biotic factors (predation, competition, mutualism, parasitism) shape the distribution of a named species.

Distinguish between species, population, habitat, niche, community and ecosystem, and use each term correctly in a written paragraph about one named ecosystem.

Define biodiversity at genetic, species and habitat levels and describe one method for measuring each, including the use of Simpson's diversity index.

Calculate Simpson's diversity index for two provided communities and interpret which is more diverse and why.

Explain the difference between natural selection and artificial selection and give one example of each relevant to conservation.

Classify the main threats to biodiversity (habitat loss and fragmentation, invasive species, overexploitation, pollution, climate change) and rank them for a named case study with justification.

Explain the criteria used by conservation organisations to set priority, including endemism, rarity, keystone species and flagship species.

Compare in situ and ex situ conservation strategies, giving one advantage and one limitation of each for a named species.

Describe the design principles of protected areas (size, shape, connectivity, edge effects, corridors) and evaluate one real protected-area design against them.

Explain how international agreements and national legislation can support conservation, and identify one enforcement weakness.

Describe the water cycle including the roles of evaporation, transpiration, condensation, precipitation, runoff and groundwater, and explain one human impact on each major flux.

Distinguish between point-source and non-point-source pollution and describe one management strategy for each in an aquatic system.

Explain the causes and consequences of eutrophication and of ocean acidification, and outline one mitigation measure for each.

Compare industrialised fishing, aquaculture and subsistence fishing in terms of yield, energy input and environmental impact, using at least two quantitative indicators.

Describe soil formation, soil texture and soil fertility, and explain how one named agricultural practice affects soil structure and nutrient content.

Explain the causes and consequences of soil erosion and desertification, and evaluate two named soil-conservation techniques.

Compare intensive and extensive terrestrial food production systems and explain the trade-offs between yield, energy use and environmental degradation.

Describe the structure and composition of the atmosphere and explain the natural greenhouse effect using energy-balance terms.

Explain the formation of photochemical smog and acid deposition, naming the primary pollutants, the chemical reactions and one impact on each of the four spheres.

Evaluate two management strategies for reducing air pollution, distinguishing between 'pollution prevention' and 'pollution cleanup' approaches.

Distinguish between the enhanced greenhouse effect and natural climate variability, and explain the evidence used to attribute recent warming to human activity.

Explain at least three feedback mechanisms in the climate system (for example ice-albedo, water vapour, cloud cover) and state whether each is positive or negative.

Compare renewable and non-renewable energy sources using at least four criteria, including energy density, reliability, carbon intensity and land use.

Calculate and interpret a simple carbon footprint from given data, and evaluate one mitigation strategy and one adaptation strategy for a named region.

Explain how international climate agreements and national policies create incentives or barriers for energy transition.

Explain the concept of ecological footprint and carrying capacity, and interpret a footprint calculation for a named country.

Evaluate strategies for reducing resource use, including circular economy approaches, recycling, and demand reduction, using at least two criteria.

Synthesise content across all eight domains by answering two full-length practice questions under timed conditions.

Identify and remediate your three weakest syllabus areas using targeted re-reading and a short self-quiz on each.

Rehearse the command terms and the structure expected for data-response and extended-response questions, including how to use case-study evidence.