ESS HL Skill Progression Mastery Tracker

Easy — Foundations

• 1Environmental value systems definedDescribe a worldview shaping how a person perceives environmental issues.ApplicationThe organising concept for the whole of ESS.Easy
• 2Inputs and outputs of a value systemIdentify education, media, culture and religion as inputs.ApplicationExplains why two people interpret the same evidence differently.Easy
• 3EcocentrismDescribe a nature-centred view prioritising ecological integrity.ApplicationOne of the three worldviews examiners expect named.Easy
• 4AnthropocentrismDescribe a people-centred view emphasising management and regulation.ApplicationThe middle position on the value system spectrum.Easy
• 5TechnocentrismDescribe a technology-centred view confident in human innovation.ApplicationThe third worldview needed for full contrast.Easy
• 6Personal and societal valuesDistinguish individual beliefs from shared cultural norms.ApplicationExplains how societies adopt collective environmental positions.Easy

Medium — Applications

• 7Cultural and religious influences on valuesExplain how belief systems shape attitudes to nature.ApplicationExplains global variation in environmental attitudes.Medium
• 8Indigenous environmental perspectivesDescribe worldviews emphasising reciprocity with land.ApplicationA perspective the current syllabus foregrounds.Medium
• 9Historical development of environmental movementsOutline key events shaping modern environmentalism.ApplicationProvides the timeline examiners expect to be cited.Medium
• 10Influential publications and their impactDescribe works that shifted public environmental awareness.ApplicationExplains sudden changes in societal value systems.Medium
• 11Environmental disasters and value changeExplain how major incidents reshape public attitudes.ApplicationLinks events directly to shifts in policy and opinion.Medium
• 12Media and environmental perceptionExplain how coverage frames environmental risk.ApplicationExplains mismatches between actual and perceived risk.Medium

Hard — Structured IB Questions

• 13Classifying a stated viewpointPlace a described position on the value system spectrum.ApplicationThe core applied task in this topic.Hard
• 14Analysing the influence of an event on valuesExplain how a specific incident changed public attitudes.ApplicationConverts a timeline into genuine analysis.Hard
• 15Comparing responses of different value systemsContrast how each worldview would address one issue.ApplicationThe most frequently set comparison in ESS.Hard
• 16Analysing your own value systemJustify a personal position using specific formative influences.ApplicationA reflective task assessed in internal assessment.Hard
• 17Evaluating the value system spectrum modelAssess its simplification of complex mixed positions.ApplicationA required critique of the central ESS framework.Hard
• 18Evaluating the role of media in shaping valuesAssess bias, framing and selective coverage.ApplicationAdds a critical dimension to a descriptive topic.Hard

Very Hard — Integrated HL Challenge

• 19Constructing an integrated analysis of a value conflictCombine worldviews, stakeholders and evidence in one account.ApplicationThe complete structure for an extended response.Very Hard
• 20Evaluating environmental justice implications of value systemsAssess whose values shape policy and whose are excluded.ApplicationConnects perspectives to justice in 1.3.Very Hard
• 21Assessing the influence of economics on environmental valuesEvaluate how income levels shape environmental priorities.ApplicationExplains differing national positions in negotiations.Very Hard
• 22Evaluating whether value systems can changeAssess evidence on shifting attitudes over a lifetime.ApplicationA conceptual evaluation examiners reward.Very Hard
• 23Assessing perspectives in a contemporary environmental issueEvaluate stakeholder positions in a current controversy.ApplicationApplies theory to a live case study.Very Hard
• 24Synthesis: perspectives, values and environmental decisionsIntegrate influences, worldviews and outcomes into one framework.ApplicationA capstone model reused throughout the course.Very Hard

Easy — Foundations

• 1Systems thinkingDescribe analysis of components, interactions and boundaries.ApplicationThe analytical approach underpinning the entire course.Easy
• 2Storages and flowsDistinguish stores of matter or energy from transfers between them.ApplicationThe vocabulary every systems diagram requires.Easy
• 3Inputs, processes and outputsIdentify what enters, changes within and leaves a system.ApplicationThe basic structure of any system description.Easy
• 4Open systemsDescribe systems exchanging both matter and energy.ApplicationThe category most natural ecosystems belong to.Easy
• 5Closed systemsDescribe systems exchanging energy but not matter.ApplicationExplains why Earth is treated as effectively closed.Easy
• 6Isolated systemsDescribe systems exchanging neither matter nor energy.ApplicationThe theoretical extreme used for contrast.Easy

Medium — Applications

• 7Transfers and transformationsDistinguish movement without change from change of form.ApplicationA distinction examiners test precisely.Medium
• 8Steady-state equilibriumDescribe fluctuation around a stable long-term average.ApplicationThe condition most healthy ecosystems display.Medium
• 9Static and stable equilibriumDistinguish unchanging systems from those returning after disturbance.ApplicationCompletes the equilibrium vocabulary.Medium
• 10Negative feedbackDescribe processes that counteract change and restore stability.ApplicationThe mechanism maintaining ecosystem equilibrium.Medium
• 11Positive feedbackDescribe processes that amplify change and destabilise systems.ApplicationThe mechanism behind runaway environmental change.Medium
• 12Tipping points and resilienceDescribe thresholds beyond which a system shifts state.ApplicationThe concept linking systems theory to climate risk.Medium

Hard — Structured IB Questions

• 13Constructing a systems diagramDraw storages and flows with correct proportional representation.ApplicationA directly assessed practical skill in ESS.Hard
• 14Analysing feedback loops in a described systemIdentify whether a loop is positive or negative and trace it.ApplicationThe core applied task in systems questions.Hard
• 15Applying the laws of thermodynamics to systemsExplain energy conservation and increasing entropy in ecosystems.ApplicationConnects systems theory to energy flow in 2.2.Hard
• 16Analysing resilience factors in a systemExplain diversity, storage size and speed of replacement.ApplicationPredicts which systems survive disturbance.Hard
• 17Analysing a tipping point in a real systemExplain the threshold and resulting state change.ApplicationApplies the concept to a specific case study.Hard
• 18Evaluating the usefulness of modelsAssess simplification against predictive value.ApplicationA required critique whenever a model is used.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating systems diagrams as toolsAssess quantification difficulties and boundary choices.ApplicationThe specific critique of the ESS core diagram.Very Hard
• 20Constructing an integrated systems analysisCombine storages, flows, feedback and resilience in one account.ApplicationThe complete structure for a systems question.Very Hard
• 21Evaluating the reliability of environmental modelsAssess assumptions, data quality and uncertainty.ApplicationConnects modelling to climate projections in 6.2.Very Hard
• 22Assessing the limits of the closed system analogy for EarthEvaluate matter inputs and outputs at planetary scale.ApplicationA precise conceptual evaluation examiners reward.Very Hard
• 23Evaluating positive feedback in climate systemsAssess amplifying mechanisms and their consequences.ApplicationConnects 1.2 directly to climate change in Chapter 6.Very Hard
• 24Synthesis: systems, feedback and environmental stabilityIntegrate structure, equilibrium and thresholds into one framework.ApplicationA capstone model applied across every chapter.Very Hard

Easy — Foundations

• 1Sustainability definedDescribe use of resources at rates allowing indefinite continuation.ApplicationThe organising concept for the whole course.Easy
• 2Natural capital and natural incomeDistinguish the stock of resources from its sustainable yield.ApplicationThe economic framing of sustainability.Easy
• 3Sustainable developmentDescribe development meeting present needs without harming future ones.ApplicationThe definition examiners expect quoted accurately.Easy
• 4The three pillars of sustainabilityIdentify environmental, social and economic dimensions.ApplicationThe framework structuring most sustainability answers.Easy
• 5Environmental justiceDescribe fair distribution of environmental benefits and burdens.ApplicationA concept the current syllabus emphasises strongly.Easy
• 6The Sustainable Development GoalsDescribe the international framework of development targets.ApplicationThe reference framework for sustainability evaluation.Easy

Medium — Applications

• 7Sustainability indicatorsIdentify measures of environmental, social and economic sustainability.ApplicationMakes an abstract concept measurable.Medium
• 8Ecological footprintDescribe the land area required to sustain a population.ApplicationThe most widely used single sustainability indicator.Medium
• 9Biocapacity and overshootDescribe available productive area against demand upon it.ApplicationQuantifies whether current use is sustainable.Medium
• 10Citizen scienceDescribe public participation in environmental data collection.ApplicationA method the syllabus names explicitly.Medium
• 11Planetary boundaries frameworkDescribe safe operating limits across environmental processes.ApplicationThe leading scientific sustainability framework.Medium
• 12Alternative economic modelsDescribe circular economy and doughnut economics approaches.ApplicationThe economic alternatives named in the syllabus.Medium

Hard — Structured IB Questions

• 13Calculating an ecological footprintCompute footprint from consumption and land productivity data.ApplicationA routinely examined quantitative task.Hard
• 14Interpreting sustainability indicator dataAnalyse indicators to judge a country's sustainability.ApplicationThe core applied task in this topic.Hard
• 15Analysing overshoot using biocapacity dataCompare footprint with available biocapacity.ApplicationTurns an indicator into a quantified conclusion.Hard
• 16Applying planetary boundaries to a described issueExplain an issue using boundary transgression evidence.ApplicationConnects the framework to a specific problem.Hard
• 17Evaluating the ecological footprint as an indicatorAssess assumptions, aggregation and omitted impacts.ApplicationA required critique of the headline indicator.Hard
• 18Evaluating the Sustainable Development GoalsAssess measurability, conflicts and enforcement.ApplicationThe standard evaluation of the international framework.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating citizen science dataAssess coverage and engagement against reliability concerns.ApplicationThe methodological critique of participatory data.Very Hard
• 20Constructing an integrated sustainability assessmentCombine indicators, frameworks and value systems in one account.ApplicationThe complete structure for an extended response.Very Hard
• 21Evaluating circular economy modelsAssess feasibility, energy demand and material limits.ApplicationA contemporary evaluation examiners reward.Very Hard
• 22Assessing environmental justice in a case studyEvaluate who bears burdens and who receives benefits.ApplicationApplies justice concepts to a specific situation.Very Hard
• 23Evaluating trade-offs between the three pillarsAssess conflicts between economic growth and ecological limits.ApplicationThe central tension in every sustainability question.Very Hard
• 24Synthesis: sustainability, capital and development choicesIntegrate measurement, frameworks and values into one model.ApplicationA capstone framework closing the whole of Chapter 1.Very Hard

Easy — Foundations

• 1Levels of ecological organisationIdentify individual, population, community, ecosystem and biome.ApplicationThe hierarchy structuring all ecological analysis.Easy
• 2Species, habitat and nicheDistinguish the organism, its address and its role.ApplicationThe vocabulary examiners test most precisely.Easy
• 3Abiotic and biotic factorsDistinguish physical conditions from living interactions.ApplicationThe two categories controlling every population.Easy
• 4Taxonomic classificationDescribe the hierarchical grouping of organisms.ApplicationThe framework for recording biodiversity data.Easy
• 5Dichotomous keysDescribe paired-choice identification of organisms.ApplicationA practical skill assessed in fieldwork.Easy
• 6Human population growthDescribe historical and projected growth of human numbers.ApplicationThe pressure underlying every environmental issue.Easy

Medium — Applications

• 7Limiting factorsExplain resources restricting population size.ApplicationExplains why populations do not grow indefinitely.Medium
• 8Carrying capacityDescribe the maximum population an environment can sustain.ApplicationThe central population concept in ESS.Medium
• 9Exponential and logistic growth curvesDescribe J-shaped and S-shaped population patterns.ApplicationThe two models examiners expect drawn and labelled.Medium
• 10Density-dependent and density-independent factorsDistinguish factors varying with population size from those that do not.ApplicationExplains different population regulation mechanisms.Medium
• 11Fundamental and realised nicheDistinguish potential range from actual range under competition.ApplicationAn HL concept explaining competitive exclusion.Medium
• 12Life-cycle strategiesContrast r-strategists and K-strategists.ApplicationPredicts which species recover after disturbance.Medium

Hard — Structured IB Questions

• 13Sampling populations using quadratsDescribe random placement and abundance estimation.ApplicationA core fieldwork technique assessed in ESS.Hard
• 14Estimating population size by capture-mark-recaptureApply the Lincoln index to estimate abundance.ApplicationA routinely examined quantitative task.Hard
• 15Analysing a population growth curveIdentify phases and explain the limiting factors involved.ApplicationThe core applied task in population questions.Hard
• 16Analysing species interactionsExplain predation, competition, mutualism and parasitism.ApplicationExplains observed population fluctuations.Hard
• 17Applying niche theory to a described communityExplain coexistence or exclusion using niche overlap.ApplicationAn HL application examiners reward.Hard
• 18Evaluating sampling techniquesAssess sample size, randomness and observer error.ApplicationA required critique of any fieldwork data.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating the capture-mark-recapture assumptionsAssess mixing, marking effects and population closure.ApplicationThe specific critique of the named method.Very Hard
• 20Constructing an integrated ecological population analysisCombine growth curves, limiting factors and species interactions.ApplicationThe complete structure for an ecology population question.Very Hard
• 21Evaluating carrying capacity applied to humansAssess technology, trade and consumption complications.ApplicationA demanding conceptual evaluation.Very Hard
• 22Assessing r and K strategies in conservation planningEvaluate which species need most intervention.ApplicationConnects population ecology to conservation in 3.3.Very Hard
• 23Evaluating models of population growthAssess simplification against observed population data.ApplicationConnects population theory to modelling in 1.2.Very Hard
• 24Synthesis: populations, niches and community structureIntegrate growth, limits and interactions into one framework.ApplicationA capstone model for ecological questions.Very Hard

Easy — Foundations

• 1Autotrophs and heterotrophsDistinguish producers from consumers by energy source.ApplicationThe basic division of every food web.Easy
• 2PhotosynthesisDescribe conversion of light energy into chemical energy.ApplicationThe entry point of energy into ecosystems.Easy
• 3RespirationDescribe release of chemical energy for metabolic work.ApplicationExplains energy loss at every trophic level.Easy
• 4Trophic levelsIdentify producer, primary consumer and higher consumer levels.ApplicationThe structure of energy flow analysis.Easy
• 5Food chains and food websDescribe linear and interconnected feeding relationships.ApplicationThe diagrams every energy flow question uses.Easy
• 6Energy losses between trophic levelsExplain respiration, excretion and uncaptured material.ApplicationExplains why food chains are short.Easy

Medium — Applications

• 7Ecological efficiencyCalculate energy transferred as a percentage of energy received.ApplicationThe quantitative measure of trophic transfer.Medium
• 8Gross and net primary productivityDistinguish total fixation from that remaining after respiration.ApplicationThe core productivity distinction in ESS.Medium
• 9Gross and net secondary productivityApply the same distinction to consumer biomass gain.ApplicationCompletes the productivity framework.Medium
• 10Pyramids of numbers, biomass and productivityDescribe the three ecological pyramid types.ApplicationThe diagrams examiners expect drawn accurately.Medium
• 11Biomass measurementDescribe dry mass determination per unit area.ApplicationThe practical basis of productivity data.Medium
• 12Sustainable yieldDescribe harvest equal to net productivity of a system.ApplicationLinks energy flow directly to resource management.Medium

Hard — Structured IB Questions

• 13Calculating net primary productivityCompute productivity from gross fixation and respiration data.ApplicationA routinely examined quantitative task.Hard
• 14Calculating ecological efficiencyCompute transfer efficiency between named trophic levels.ApplicationA core ESS calculation.Hard
• 15Constructing ecological pyramids from dataDraw pyramids to scale from supplied figures.ApplicationA directly assessed practical skill.Hard
• 16Analysing energy flow through a food webTrace energy and quantify losses at each transfer.ApplicationThe core applied task in this topic.Hard
• 17Analysing human impacts on energy flowsExplain how harvesting and land use alter productivity.ApplicationConnects ecology to human activity.Hard
• 18Calculating maximum sustainable yieldCompute harvestable amount from productivity data.ApplicationConnects energy flow to fisheries in 4.3.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating ecological pyramidsAssess seasonal variation and inverted pyramid cases.ApplicationA required critique of the standard diagrams.Very Hard
• 20Evaluating productivity measurement methodsAssess destructive sampling and estimation error.ApplicationThe methodological critique of productivity data.Very Hard
• 21Constructing an integrated energy flow analysisCombine trophic structure, efficiency and human impact.ApplicationThe complete structure for an energy question.Very Hard
• 22Evaluating the implications of trophic efficiency for dietAssess land and energy costs of animal-based diets.ApplicationConnects 2.2 directly to food systems in 5.2.Very Hard
• 23Assessing energy flow disruption in degraded ecosystemsEvaluate productivity loss following disturbance.ApplicationApplies energy theory to a real problem.Very Hard
• 24Synthesis: energy, biomass and ecosystem productivityIntegrate transfer, loss and yield into one framework.ApplicationA capstone model for ecosystem questions.Very Hard

Easy — Foundations

• 1Biogeochemical cycles definedDescribe cyclical movement of elements through biotic and abiotic stores.ApplicationDistinguishes matter cycling from one-way energy flow.Easy
• 2Stores and flows in nutrient cyclesIdentify reservoirs and the transfers between them.ApplicationThe systems vocabulary applied to matter.Easy
• 3The carbon cycleDescribe the movement of carbon between major stores.ApplicationThe cycle most examined in the entire course.Easy
• 4Carbon storesIdentify atmosphere, oceans, biomass, soil and fossil deposits.ApplicationThe reservoirs whose sizes determine climate.Easy
• 5Photosynthesis and respiration in the carbon cycleExplain the two processes as opposing carbon flows.ApplicationThe biological engine of carbon cycling.Easy
• 6Carbon sequestrationDescribe long-term storage of carbon in sinks.ApplicationThe basis of natural climate mitigation.Easy

Medium — Applications

• 7Human disruption of the carbon cycleExplain combustion and land use change as carbon flows.ApplicationThe direct link between human activity and climate.Medium
• 8Strategies to reduce carbon impactsIdentify emission reduction, protection and enhancement of sinks.ApplicationThe policy response derived from the cycle.Medium
• 9The nitrogen cycleDescribe fixation, nitrification, assimilation and denitrification.ApplicationThe second major cycle examined in ESS.Medium
• 10Nitrogen fixationDescribe conversion of atmospheric nitrogen into usable forms.ApplicationThe bottleneck controlling ecosystem productivity.Medium
• 11Human influences on the nitrogen cycleExplain fertiliser production, combustion and cultivation effects.ApplicationExplains eutrophication and nitrous oxide emissions.Medium
• 12Nutrient cycles and ecosystem productivityExplain nutrient availability as a limiting factor.ApplicationConnects nutrient cycling to energy flow in 2.2.Medium

Hard — Structured IB Questions

• 13Constructing a carbon cycle diagramDraw stores and flows with correct labelling.ApplicationA directly assessed diagram skill.Hard
• 14Analysing quantitative flux dataInterpret carbon flow figures to identify imbalance.ApplicationThe core applied task in cycle questions.Hard
• 15Analysing the effect of deforestation on carbon storageTrace changes in stores and atmospheric concentration.ApplicationA frequently examined applied scenario.Hard
• 16Analysing the consequences of nitrogen enrichmentExplain eutrophication pathways from excess nitrogen.ApplicationConnects 2.3 directly to water pollution in 4.4.Hard
• 17Comparing carbon and nitrogen cyclesContrast reservoir sizes, turnover rates and human impact.ApplicationA comparison examiners set regularly.Hard
• 18Evaluating carbon sequestration strategiesAssess permanence, capacity and cost of carbon sinks.ApplicationConnects cycling to climate mitigation in 6.3.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating the reliability of flux measurementsAssess estimation difficulty at global scale.ApplicationA required critique of global cycle data.Very Hard
• 20Constructing an integrated nutrient cycle analysisCombine stores, flows, disruption and management.ApplicationThe complete structure for a cycles question.Very Hard
• 21Evaluating soil carbon management strategiesAssess agricultural practices affecting soil carbon.ApplicationConnects 2.3 to soil systems in 5.1.Very Hard
• 22Assessing the ocean as a carbon sinkEvaluate uptake capacity and acidification consequences.ApplicationConnects cycling to ocean processes in 4.1.Very Hard
• 23Evaluating planetary boundary transgression for nitrogenAssess the extent and consequences of nitrogen overload.ApplicationConnects cycles to the framework in 1.3.Very Hard
• 24Synthesis: cycles, disruption and environmental changeIntegrate stores, flows and human impact into one framework.ApplicationA capstone model for biogeochemical questions.Very Hard

Easy — Foundations

• 1Weather and climate distinguishedSeparate short-term conditions from long-term averages.ApplicationA distinction examiners test in the first question.Easy
• 2Insolation and latitudeExplain uneven heating of the Earth's surface.ApplicationThe driver of all atmospheric circulation.Easy
• 3Tricellular atmospheric circulationDescribe Hadley, Ferrel and Polar cells.ApplicationThe model explaining global climate patterns.Easy
• 4The Coriolis effectExplain deflection of moving air by Earth's rotation.ApplicationExplains prevailing wind directions.Easy
• 5Pressure belts and precipitation patternsExplain rising and sinking air producing wet and dry zones.ApplicationExplains the location of deserts and rainforests.Easy
• 6Ocean currentsDescribe surface and deep circulation transporting heat.ApplicationThe oceanic component of global climate.Easy

Medium — Applications

• 7Thermohaline circulationDescribe density-driven global ocean conveyor circulation.ApplicationExplains regional climate anomalies.Medium
• 8Major terrestrial biomesIdentify forest, grassland, desert and tundra biomes.ApplicationThe classification linking climate to ecosystems.Medium
• 9Biome distribution and climateExplain temperature and precipitation determining biome type.ApplicationThe core relationship in this topic.Medium
• 10Climate graphs and biome identificationInterpret temperature and rainfall data to identify a biome.ApplicationA directly assessed practical skill.Medium
• 11El Nino Southern OscillationDescribe periodic changes in Pacific circulation and climate.ApplicationThe named climate variability system in the syllabus.Medium
• 12Tropical cyclones and climate changeExplain the link between ocean warming and storm intensity.ApplicationA contemporary application examiners expect.Medium

Hard — Structured IB Questions

• 13Interpreting a climate graphExtract temperature range, total rainfall and seasonality.ApplicationThe core quantitative task in this topic.Hard
• 14Analysing biome distribution using circulationExplain a biome's location using atmospheric cells.ApplicationConnects circulation theory to observed patterns.Hard
• 15Analysing the effects of an El Nino eventTrace consequences for rainfall, fisheries and agriculture.ApplicationA frequently examined applied scenario.Hard
• 16Analysing ocean current influence on regional climateExplain warming or cooling effects on adjacent land.ApplicationExplains climate anomalies at a given latitude.Hard
• 17Applying biome knowledge to ecosystem productivityExplain productivity differences using climate conditions.ApplicationConnects 2.4 to energy flow in 2.2.Hard
• 18Evaluating biome classification systemsAssess boundary definition and transitional zones.ApplicationA required critique of the classification.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating predictions of biome shift under warmingAssess model uncertainty and species migration rates.ApplicationConnects biomes to climate change in 6.2.Very Hard
• 20Constructing an integrated climate systems analysisCombine circulation, currents and biome distribution.ApplicationThe complete structure for a climate question.Very Hard
• 21Evaluating evidence linking cyclones to climate changeAssess attribution difficulty and record length.ApplicationA demanding evaluation of contested evidence.Very Hard
• 22Assessing the vulnerability of thermohaline circulationEvaluate freshwater input and circulation slowdown risk.ApplicationConnects ocean circulation to tipping points in 1.2.Very Hard
• 23Evaluating the societal impacts of climate variabilityAssess consequences for food and water security.ApplicationConnects climate systems to human systems.Very Hard
• 24Synthesis: circulation, climate and biome distributionIntegrate energy, circulation and ecosystems into one framework.ApplicationA capstone model for global systems questions.Very Hard

Easy — Foundations

• 1Succession definedDescribe directional change in community composition over time.ApplicationThe core temporal concept in ecosystem ecology.Easy
• 2Primary successionDescribe colonisation of newly exposed bare substrate.ApplicationThe starting case for succession analysis.Easy
• 3Secondary successionDescribe recolonisation where soil already exists.ApplicationExplains faster recovery after disturbance.Easy
• 4Pioneer speciesDescribe early colonisers tolerant of harsh conditions.ApplicationThe first stage of every seral sequence.Easy
• 5Seres and seral stagesDescribe the sequence of communities during succession.ApplicationThe vocabulary examiners expect used precisely.Easy
• 6Climax communitiesDescribe the stable endpoint community of a succession.ApplicationThe traditional endpoint of the succession model.Easy

Medium — Applications

• 7ZonationDescribe spatial change in community along an environmental gradient.ApplicationFrequently confused with succession in exams.Medium
• 8Changes in productivity during successionExplain gross and net productivity change across seral stages.ApplicationLinks succession directly to energy flow in 2.2.Medium
• 9Changes in diversity and biomass during successionExplain increasing complexity through seral stages.ApplicationThe measurable pattern examiners test.Medium
• 10Ecosystem stability and resilienceExplain the capacity to resist and recover from disturbance.ApplicationConnects succession to systems theory in 1.2.Medium
• 11Factors influencing successionIdentify climate, disturbance and human interference.ApplicationExplains arrested and deflected succession.Medium
• 12Reproductive strategies during successionExplain the shift from r-strategists to K-strategists.ApplicationConnects succession to population strategies in 2.1.Medium

Hard — Structured IB Questions

• 13Analysing a described seral sequenceIdentify stages and explain the changes at each.ApplicationThe core applied task in succession questions.Hard
• 14Analysing productivity change across successionExplain why net productivity falls as climax is approached.ApplicationA frequently examined conceptual point.Hard
• 15Distinguishing zonation from succession in field dataClassify observed pattern correctly from evidence.ApplicationThe distinction that separates strong candidates.Hard
• 16Analysing the effect of disturbance on successionExplain arrested succession and plagioclimax communities.ApplicationExplains human-maintained ecosystems such as grazing land.Hard
• 17Analysing diversity data across seral stagesInterpret species richness and evenness changes.ApplicationConnects succession to biodiversity measurement in 3.1.Hard
• 18Evaluating the climax community conceptAssess whether a single stable endpoint exists.ApplicationA required critique of the traditional model.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating resilience of early and late successional systemsAssess recovery capacity across seral stages.ApplicationA conceptual evaluation examiners reward.Very Hard
• 20Constructing an integrated succession analysisCombine stages, productivity, diversity and disturbance.ApplicationThe complete structure for a succession question.Very Hard
• 21Evaluating succession-based restoration approachesAssess assisted succession in habitat restoration.ApplicationConnects 2.5 to restoration in 3.3.Very Hard
• 22Assessing human interference in successionEvaluate deflected succession from land management.ApplicationApplies succession theory to real landscapes.Very Hard
• 23Evaluating succession models against observed dataAssess deterministic sequences against stochastic change.ApplicationA demanding critique of ecological prediction.Very Hard
• 24Synthesis: succession, stability and ecosystem changeIntegrate sequence, productivity and resilience into one framework.ApplicationA capstone model closing the whole of Chapter 2.Very Hard

Easy — Foundations

• 1Biodiversity definedDescribe the variety of life at genetic, species and ecosystem levels.ApplicationThe three-level definition examiners require.Easy
• 2Species diversityDescribe richness and evenness within a community.ApplicationThe most commonly measured level of biodiversity.Easy
• 3Genetic diversityDescribe variation in alleles within a population.ApplicationDetermines a population's capacity to adapt.Easy
• 4Habitat and ecosystem diversityDescribe the range of ecosystems within an area.ApplicationThe largest-scale measure of biodiversity.Easy
• 5Biodiversity and ecosystem resilienceExplain how diversity buffers systems against disturbance.ApplicationConnects biodiversity directly to systems theory in 1.2.Easy
• 6Natural selectionDescribe differential survival and reproduction of variants.ApplicationThe mechanism producing evolutionary change.Easy

Medium — Applications

• 7SpeciationDescribe formation of new species from existing populations.ApplicationThe process generating biodiversity over time.Medium
• 8Reproductive isolationDescribe barriers preventing gene flow between populations.ApplicationThe requirement for speciation to occur.Medium
• 9Biodiversity hotspotsDescribe regions of high endemism under significant threat.ApplicationThe prioritisation framework used in conservation.Medium
• 10The geological timescaleDescribe major divisions of Earth history.ApplicationThe temporal context for extinction analysis.Medium
• 11Mass extinction eventsDescribe past episodes of rapid widespread species loss.ApplicationThe baseline against which current loss is judged.Medium
• 12The AnthropoceneDescribe the proposed epoch defined by human impact.ApplicationThe framing concept for modern biodiversity loss.Medium

Hard — Structured IB Questions

• 13Calculating a diversity indexCompute Simpson's index from species abundance data.ApplicationA routinely examined quantitative task.Hard
• 14Interpreting diversity index valuesCompare communities and explain differences in diversity.ApplicationTurns a calculation into an ecological conclusion.Hard
• 15Analysing human effects on evolutionExplain selection pressures from harvesting and pesticides.ApplicationExplains resistance and size reduction in exploited species.Hard
• 16Analysing speciation in a described scenarioExplain isolation and divergence from case evidence.ApplicationThe core applied task in evolution questions.Hard
• 17Analysing biodiversity hotspot dataInterpret endemism and threat data for prioritisation.ApplicationConnects measurement to conservation decisions.Hard
• 18Evaluating diversity indicesAssess sampling effort, sensitivity and what they omit.ApplicationA required critique of biodiversity measurement.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating evidence for a sixth mass extinctionAssess extinction rate estimates against the fossil baseline.ApplicationA demanding evaluation of contested evidence.Very Hard
• 20Constructing an integrated biodiversity analysisCombine measurement, evolution and threat in one account.ApplicationThe complete structure for a biodiversity question.Very Hard
• 21Evaluating the hotspot approach to conservationAssess prioritisation against neglect of other regions.ApplicationA frequently examined conservation evaluation.Very Hard
• 22Assessing genetic diversity in small populationsEvaluate inbreeding and reduced adaptive capacity.ApplicationConnects biodiversity theory to conservation practice.Very Hard
• 23Evaluating the Anthropocene as a scientific conceptAssess evidence and boundary definition debates.ApplicationA conceptual evaluation examiners reward.Very Hard
• 24Synthesis: diversity, evolution and ecosystem functionIntegrate levels, processes and threats into one framework.ApplicationA capstone model for biodiversity questions.Very Hard

Easy — Foundations

• 1Major threats to biodiversityIdentify habitat loss, overexploitation, invasive species, pollution and climate change.ApplicationThe framework structuring every threat answer.Easy
• 2Habitat loss and fragmentationExplain reduction and division of available habitat.ApplicationThe single largest driver of species loss.Easy
• 3OverexploitationExplain harvesting exceeding population replacement rates.ApplicationConnects biodiversity loss to resource use.Easy
• 4Invasive alien speciesExplain introduced species outcompeting natives.ApplicationA leading cause of island species extinction.Easy
• 5Pollution as a biodiversity threatExplain toxic, nutrient and plastic pressures on species.ApplicationConnects biodiversity to pollution in 4.4 and 8.3.Easy
• 6Climate change and species distributionExplain range shifts and phenological mismatch.ApplicationConnects biodiversity to Chapter 6.Easy

Medium — Applications

• 7Conservation status assessmentDescribe criteria used to classify species threat levels.ApplicationThe framework behind red list categories.Medium
• 8The tragedy of the commonsExplain degradation of shared unregulated resources.ApplicationThe central model for common resource loss.Medium
• 9Threats to biodiversity hotspotsExplain concentrated pressure on high endemism regions.ApplicationExplains disproportionate global extinction risk.Medium
• 10Key biodiversity areasDescribe sites identified as significant for species persistence.ApplicationThe site-based conservation prioritisation framework.Medium
• 11Indigenous land management approachesDescribe traditional practices sustaining biodiversity.ApplicationA perspective the current syllabus foregrounds.Medium
• 12Loss of biosphere integrityDescribe biodiversity loss as a planetary boundary transgression.ApplicationConnects threats to the framework in 1.3.Medium

Hard — Structured IB Questions

• 13Analysing threats to a named speciesIdentify the dominant pressure from case evidence.ApplicationThe core applied task in this topic.Hard
• 14Analysing the effects of habitat fragmentationExplain edge effects, isolation and population viability.ApplicationA frequently examined mechanism.Hard
• 15Analysing a tragedy of the commons scenarioExplain individual incentives producing collective loss.ApplicationApplies the model to a specific resource.Hard
• 16Analysing conservation status dataInterpret population trend and range data for classification.ApplicationConnects assessment criteria to actual evidence.Hard
• 17Analysing an invasive species case studyExplain introduction, spread and ecological consequences.ApplicationA case study examiners expect in detail.Hard
• 18Evaluating conservation status assessmentAssess data gaps and inconsistent application of criteria.ApplicationA required critique of red list classification.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating the tragedy of the commons modelAssess evidence of successful community management.ApplicationA critical point that lifts an evaluation.Very Hard
• 20Constructing an integrated threat analysisCombine multiple pressures and their interactions.ApplicationThe complete structure for a threat question.Very Hard
• 21Evaluating Indigenous land management effectivenessAssess biodiversity outcomes and knowledge integration.ApplicationA contemporary evaluation examiners reward.Very Hard
• 22Assessing environmental justice in biodiversity lossEvaluate who benefits from exploitation and who bears loss.ApplicationConnects biodiversity to justice in 1.3.Very Hard
• 23Evaluating the interaction of multiple threatsAssess cumulative and synergistic pressure on populations.ApplicationA demanding synthesis examiners reward highly.Very Hard
• 24Synthesis: pressures, drivers and biodiversity declineIntegrate threats, mechanisms and justice into one framework.ApplicationA capstone model for biodiversity loss questions.Very Hard

Easy — Foundations

• 1Arguments for preserving biodiversityIdentify ecological, economic, ethical and aesthetic arguments.ApplicationThe justification framework for every conservation answer.Easy
• 2In-situ conservationDescribe protection of species within their natural habitat.ApplicationThe preferred conservation approach in most cases.Easy
• 3Ex-situ conservationDescribe protection outside the natural habitat.ApplicationThe fallback approach for critically threatened species.Easy
• 4Protected area designDescribe size, shape, connectivity and buffer considerations.ApplicationThe applied design principles examiners test.Easy
• 5Habitat corridorsDescribe linked habitat allowing movement between areas.ApplicationAddresses fragmentation identified in 3.2.Easy
• 6Species-based conservation approachesDescribe flagship, keystone and umbrella species strategies.ApplicationExplains why particular species attract funding.Easy

Medium — Applications

• 7Habitat restorationDescribe returning degraded habitat to functional condition.ApplicationThe active intervention approach to recovery.Medium
• 8RewildingDescribe restoring natural processes with reduced management.ApplicationA contemporary approach named in the syllabus.Medium
• 9Planetary boundaries for biodiversityDescribe safe limits for biosphere integrity.ApplicationConnects conservation to the framework in 1.3.Medium
• 10Conservation organisationsDescribe governmental, intergovernmental and non-governmental roles.ApplicationExplains how conservation is actually funded and delivered.Medium
• 11EcotourismDescribe tourism generating conservation funding and incentives.ApplicationLinks conservation to local economic benefit.Medium
• 12Assessment of conservation successDescribe indicators used to judge project outcomes.ApplicationMakes conservation claims measurable.Medium

Hard — Structured IB Questions

• 13Applying protected area design principlesJustify a reserve design for a described species.ApplicationThe core applied task in this topic.Hard
• 14Analysing the effectiveness of a conservation case studyEvaluate outcomes against stated objectives.ApplicationThe case study skill examiners expect.Hard
• 15Analysing corridor design for a fragmented landscapeExplain connectivity benefits and practical constraints.ApplicationA frequently examined applied task.Hard
• 16Comparing in-situ and ex-situ conservationContrast cost, effectiveness and ecological realism.ApplicationThe most commonly set conservation comparison.Hard
• 17Analysing ecotourism impactsEvaluate revenue and awareness against disturbance.ApplicationRequires balance rather than endorsement.Hard
• 18Evaluating rewilding as a conservation strategyAssess ecological benefits against social conflict.ApplicationA contested contemporary evaluation.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating protected areas as a conservation toolAssess enforcement, funding and paper park problems.ApplicationA required critique of the dominant approach.Very Hard
• 20Constructing an integrated conservation strategyCombine protection, restoration, funding and community.ApplicationThe complete structure for a conservation question.Very Hard
• 21Evaluating conservation perspectives across value systemsAssess how worldviews shape conservation priorities.ApplicationConnects conservation to Chapter 1 explicitly.Very Hard
• 22Assessing community involvement in conservation successEvaluate local participation as a determinant of outcomes.ApplicationExplains why externally imposed projects often fail.Very Hard
• 23Evaluating restoration against protection prioritiesJudge resource allocation between the two approaches.ApplicationA demanding policy-level evaluation.Very Hard
• 24Synthesis: conservation, restoration and biodiversity futuresIntegrate strategy, evaluation and values into one framework.ApplicationA capstone model closing the whole of Chapter 3.Very Hard

Easy — Foundations

• 1The hydrological cycleDescribe stores and flows of water through the Earth system.ApplicationThe systems model underlying all water topics.Easy
• 2Water storagesIdentify oceans, ice, groundwater, lakes and atmosphere.ApplicationThe reservoirs whose sizes determine availability.Easy
• 3Flows in the hydrological cycleIdentify evaporation, transpiration, precipitation and runoff.ApplicationThe transfers linking water stores.Easy
• 4Residence timeDescribe the average duration water remains in a store.ApplicationExplains why groundwater depletion is effectively permanent.Easy
• 5Human impacts on the hydrological cycleExplain abstraction, damming, land use and urbanisation effects.ApplicationThe direct human interference in water systems.Easy
• 6Physical properties of waterDescribe density anomaly, heat capacity and latent heat.ApplicationExplains water's role in climate regulation.Easy

Medium — Applications

• 7Chemical properties of waterDescribe polarity and solvent behaviour.ApplicationExplains transport of nutrients and pollutants.Medium
• 8Ocean carbon sequestrationDescribe dissolution and biological uptake of carbon dioxide.ApplicationThe ocean's role in the carbon cycle from 2.3.Medium
• 9Ocean acidificationExplain reduced ocean pH from carbon dioxide uptake.ApplicationThe chemical consequence of carbon emissions.Medium
• 10Water stratificationDescribe layering by temperature and density.ApplicationExplains nutrient limitation in surface waters.Medium
• 11UpwellingDescribe wind-driven rise of nutrient-rich deep water.ApplicationExplains the location of the most productive fisheries.Medium
• 12Ocean circulation and heat transportDescribe surface and deep currents redistributing heat.ApplicationConnects ocean systems to climate in 2.4.Medium

Hard — Structured IB Questions

• 13Constructing a hydrological cycle diagramDraw stores and flows with correct labelling.ApplicationA directly assessed diagram skill.Hard
• 14Analysing human alteration of a water systemTrace changes to flows following a specific intervention.ApplicationThe core applied task in this topic.Hard
• 15Analysing the consequences of ocean acidificationExplain effects on calcifying organisms and food webs.ApplicationConnects chemistry to ecosystem consequences.Hard
• 16Analysing stratification and productivityExplain nutrient limitation caused by stable layering.ApplicationConnects physical processes to biological outcomes.Hard
• 17Analysing upwelling systemsExplain high productivity and fishery importance.ApplicationConnects ocean processes to food production in 4.3.Hard
• 18Evaluating ocean carbon sequestration capacityAssess uptake limits and acidification consequences.ApplicationConnects water systems to climate mitigation in 6.3.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating the reliability of hydrological dataAssess measurement difficulty across large stores.ApplicationA required critique of global water figures.Very Hard
• 20Constructing an integrated water systems analysisCombine stores, flows, human impact and consequences.ApplicationThe complete structure for a water systems question.Very Hard
• 21Evaluating dam construction impactsAssess water supply and energy against ecological disruption.ApplicationA frequently examined case study evaluation.Very Hard
• 22Assessing groundwater depletion sustainabilityEvaluate abstraction rates against recharge rates.ApplicationApplies natural capital reasoning to water.Very Hard
• 23Evaluating ocean circulation change under warmingAssess evidence for slowdown and its consequences.ApplicationConnects ocean systems to tipping points in 1.2.Very Hard
• 24Synthesis: water systems, oceans and global processesIntegrate cycle, properties and human impact into one framework.ApplicationA capstone model for water questions.Very Hard

Easy — Foundations

• 1Global freshwater availabilityDescribe the small proportion of water accessible for human use.ApplicationThe context for every water scarcity discussion.Easy
• 2Factors affecting freshwater availabilityIdentify climate, geology, storage and infrastructure.ApplicationExplains uneven global water distribution.Easy
• 3Water use by sectorCompare agricultural, industrial and domestic consumption.ApplicationIdentifies where reductions would matter most.Easy
• 4Physical and economic water scarcityDistinguish insufficient supply from insufficient infrastructure.ApplicationA distinction examiners test precisely.Easy
• 5Water stress definedDescribe demand approaching or exceeding available supply.ApplicationThe measurable indicator of water pressure.Easy
• 6Methods of increasing water supplyIdentify reservoirs, desalination, rainwater harvesting and transfer.ApplicationThe supply-side toolkit for scarcity.Easy

Medium — Applications

• 7DesalinationDescribe removal of salt to produce freshwater.ApplicationThe most energy-intensive supply option.Medium
• 8Groundwater abstractionDescribe extraction from aquifers and depletion risks.ApplicationThe most widely used and most depleted source.Medium
• 9Demand-side water managementIdentify pricing, efficiency, and behaviour change measures.ApplicationThe alternative to expanding supply.Medium
• 10Water equity and accessDescribe unequal distribution of safe water access.ApplicationConnects water to environmental justice in 1.3.Medium
• 11Transboundary water conflictDescribe disputes over shared river basins.ApplicationExplains international tension over water resources.Medium
• 12Virtual water and water footprintsDescribe water embedded in traded goods.ApplicationReveals hidden water use in consumption patterns.Medium

Hard — Structured IB Questions

• 13Calculating a water footprintCompute water use from consumption data.ApplicationA routinely examined quantitative task.Hard
• 14Interpreting water stress dataAnalyse availability and demand data for a region.ApplicationThe core applied task in this topic.Hard
• 15Analysing water use patterns across countriesExplain sectoral differences using development level.ApplicationConnects water use to economic structure.Hard
• 16Analysing a transboundary water disputeExplain upstream and downstream stakeholder positions.ApplicationA case study examiners expect in detail.Hard
• 17Comparing supply-side and demand-side strategiesContrast cost, sustainability and equity outcomes.ApplicationThe most frequently set water management comparison.Hard
• 18Evaluating desalination as a solutionAssess energy cost, brine disposal and dependence.ApplicationA required critique of the technological fix.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating groundwater abstraction sustainabilityAssess recharge rates against extraction levels.ApplicationApplies sustainability criteria to a specific resource.Very Hard
• 20Constructing an integrated water security strategyCombine supply, demand, equity and governance measures.ApplicationThe complete structure for a water security question.Very Hard
• 21Evaluating water pricing as a management toolAssess efficiency gains against equity of access.ApplicationThe central tension in water policy.Very Hard
• 22Assessing climate change impacts on water securityEvaluate altered precipitation and glacial storage loss.ApplicationConnects water to Chapter 6.Very Hard
• 23Evaluating water equity in policy designAssess whether solutions reach the least served populations.ApplicationA justice-focused evaluation examiners reward.Very Hard
• 24Synthesis: availability, demand and water securityIntegrate supply, use, equity and governance into one framework.ApplicationA capstone model for water resource questions.Very Hard

Easy — Foundations

• 1Aquatic food websDescribe trophic relationships in marine and freshwater systems.ApplicationThe ecological basis of all fisheries analysis.Easy
• 2Ocean productivity and nutrient dynamicsExplain nutrient limitation of primary productivity.ApplicationExplains why most ocean areas are unproductive.Easy
• 3Rising human demand for aquatic foodDescribe growth in consumption and its drivers.ApplicationThe pressure underlying overexploitation.Easy
• 4Overexploitation of fisheriesExplain harvesting exceeding population replacement.ApplicationThe central problem in this topic.Easy
• 5Maximum sustainable yieldDescribe the largest harvest a stock can sustain indefinitely.ApplicationThe management target derived from population ecology.Easy
• 6Fish stock assessmentDescribe methods of estimating population size and status.ApplicationThe evidence base for quota setting.Easy

Medium — Applications

• 7Bycatch and destructive fishing methodsDescribe non-target catch and habitat damage.ApplicationThe ecological cost beyond target species.Medium
• 8Mitigation strategies in fisheriesIdentify quotas, gear restrictions, closed seasons and reserves.ApplicationThe management toolkit examiners expect.Medium
• 9Marine protected areasDescribe closed zones supporting stock recovery.ApplicationThe spatial approach to fisheries management.Medium
• 10AquacultureDescribe farmed production of aquatic organisms.ApplicationThe fastest growing food production sector.Medium
• 11Environmental impacts of aquacultureExplain effluent, escapes, disease and feed demand.ApplicationThe counterweight to aquaculture as a solution.Medium
• 12Climate change and aquatic food systemsExplain warming and acidification effects on stocks.ApplicationConnects fisheries to Chapters 2 and 6.Medium

Hard — Structured IB Questions

• 13Calculating sustainable yield from stock dataCompute harvestable amounts from productivity figures.ApplicationA routinely examined quantitative task.Hard
• 14Interpreting fish stock assessment dataAnalyse catch and biomass trends to judge stock status.ApplicationThe core applied task in this topic.Hard
• 15Analysing the collapse of a named fisheryExplain the sequence of events leading to collapse.ApplicationA case study examiners expect in detail.Hard
• 16Analysing recovery of a depleted stockExplain conditions required for population rebuilding.ApplicationExplains why some stocks recover and others do not.Hard
• 17Analysing aquaculture as a substitute for wild captureEvaluate feed conversion and wild fish input.ApplicationA sophisticated point examiners reward.Hard
• 18Evaluating maximum sustainable yield as a targetAssess data uncertainty and single-species focus.ApplicationA required critique of the standard management target.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating marine protected areasAssess spillover benefits against enforcement difficulty.ApplicationThe standard evaluation of spatial management.Very Hard
• 20Constructing an integrated fisheries management strategyCombine quotas, gear, protection and monitoring.ApplicationThe complete structure for a fisheries question.Very Hard
• 21Evaluating the regulation of international watersAssess enforcement in areas beyond national jurisdiction.ApplicationConnects fisheries to the commons problem in 3.2.Very Hard
• 22Assessing ethical issues in marine harvestingEvaluate welfare, equity and intergenerational concerns.ApplicationA perspective the current syllabus emphasises.Very Hard
• 23Evaluating aquaculture sustainabilityAssess environmental cost against food security benefit.ApplicationA balanced evaluation examiners reward.Very Hard
• 24Synthesis: harvesting, yield and aquatic sustainabilityIntegrate ecology, exploitation and management into one framework.ApplicationA capstone model for aquatic resource questions.Very Hard

Easy — Foundations

• 1Sources of water pollutionIdentify point and non-point sources of contamination.ApplicationThe classification structuring every pollution answer.Easy
• 2Types of water pollutantsIdentify organic, inorganic, thermal, biological and plastic pollutants.ApplicationThe categories examiners expect distinguished.Easy
• 3Plastic contaminationDescribe macroplastic and microplastic pollution pathways.ApplicationA contemporary pollution issue named in the syllabus.Easy
• 4EutrophicationDescribe nutrient enrichment leading to oxygen depletion.ApplicationThe most examined water pollution process.Easy
• 5The eutrophication sequenceExplain nutrient input, algal bloom, decomposition and oxygen loss.ApplicationThe mechanism required for full marks.Easy
• 6Biochemical oxygen demandDescribe oxygen consumed by decomposing organic matter.ApplicationThe key indicator of organic pollution.Easy

Medium — Applications

• 7Indicator speciesDescribe organisms whose presence signals water quality.ApplicationThe biological approach to monitoring.Medium
• 8Biotic indicesDescribe scoring systems using pollution-tolerant species.ApplicationA practical monitoring method assessed in fieldwork.Medium
• 9Water quality monitoring methodsIdentify chemical, physical and biological measurements.ApplicationThe toolkit for assessing pollution.Medium
• 10Drinking water standardsDescribe thresholds for safe human consumption.ApplicationConnects pollution to human health outcomes.Medium
• 11Sewage treatmentDescribe primary, secondary and tertiary treatment stages.ApplicationThe main engineered pollution management approach.Medium
• 12Pollution management strategiesIdentify prevention, treatment and restoration approaches.ApplicationThe three-level management model in ESS.Medium

Hard — Structured IB Questions

• 13Interpreting water quality dataAnalyse oxygen, nutrient and indicator data together.ApplicationThe core applied task in this topic.Hard
• 14Calculating a biotic indexCompute an index score from species abundance data.ApplicationA directly assessed practical skill.Hard
• 15Analysing an eutrophication case studyExplain causes, sequence and consequences at a named site.ApplicationA case study examiners expect in detail.Hard
• 16Analysing the pathway of a pollutantTrace movement from source through the water system.ApplicationConnects pollution to hydrological systems in 4.1.Hard
• 17Applying the pollution management modelJustify measures at each of the three intervention levels.ApplicationThe structure examiners reward most highly.Hard
• 18Evaluating indicator species as a monitoring toolAssess sensitivity, cost and interpretation difficulty.ApplicationA required critique of biological monitoring.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating sewage treatment effectivenessAssess capacity, cost and residual contamination.ApplicationThe standard critique of engineered solutions.Very Hard
• 20Constructing an integrated pollution management strategyCombine prevention, treatment and restoration measures.ApplicationThe complete structure for a pollution question.Very Hard
• 21Evaluating strategies to reduce plastic pollutionAssess bans, recycling and behaviour change measures.ApplicationA contemporary policy evaluation.Very Hard
• 22Assessing environmental justice in water pollutionEvaluate who is exposed and who causes contamination.ApplicationConnects pollution to justice in 1.3.Very Hard
• 23Evaluating agricultural pollution control measuresAssess buffer strips, timing and nutrient management.ApplicationConnects water pollution to agriculture in 5.2.Very Hard
• 24Synthesis: pollution, monitoring and water quality managementIntegrate sources, effects and management into one framework.ApplicationA capstone model closing the whole of Chapter 4.Very Hard

Easy — Foundations

• 1Soil as a systemDescribe soil as a dynamic system with inputs, stores and outputs.ApplicationApplies systems thinking from 1.2 to soil.Easy
• 2Soil compositionIdentify mineral particles, organic matter, water and air.ApplicationThe four components examiners expect quantified.Easy
• 3Soil textureDescribe the relative proportions of sand, silt and clay.ApplicationDetermines drainage, aeration and fertility.Easy
• 4The soil texture triangleUse proportions to classify a soil type.ApplicationA directly assessed practical skill.Easy
• 5Soil structureDescribe the arrangement of particles into aggregates.ApplicationDetermines root penetration and water movement.Easy
• 6Soil functionsIdentify support, nutrient supply, water storage and carbon storage.ApplicationExplains why soil degradation matters so widely.Easy

Medium — Applications

• 7Soil profiles and horizonsDescribe the vertical sequence of soil layers.ApplicationThe framework for describing any soil.Medium
• 8Factors affecting soil formationIdentify parent material, climate, organisms, relief and time.ApplicationThe five factors examiners expect named.Medium
• 9Weathering processesDescribe physical, chemical and biological breakdown of rock.ApplicationThe source of the mineral fraction of soil.Medium
• 10Variation in soil characteristicsCompare soils across contrasting biomes.ApplicationConnects soil to biome distribution in 2.4.Medium
• 11Soil as a carbon storeDescribe organic carbon held in soil systems.ApplicationConnects soil to the carbon cycle in 2.3.Medium
• 12Carbon release from soilsExplain decomposition, drainage and cultivation releasing carbon.ApplicationA significant and often overlooked emission source.Medium

Hard — Structured IB Questions

• 13Determining soil texture from dataClassify a soil using the texture triangle.ApplicationA routinely examined quantitative task.Hard
• 14Analysing a soil profileInterpret horizons to infer formation processes.ApplicationThe core applied task in soil questions.Hard
• 15Analysing soil properties and agricultural suitabilityExplain how texture and structure affect productivity.ApplicationConnects soil science to farming in 5.2.Hard
• 16Analysing soil degradation processesExplain erosion, compaction, salinisation and nutrient loss.ApplicationThe main soil problems examiners test.Hard
• 17Analysing the effect of land use on soil carbonTrace carbon change following cultivation or restoration.ApplicationConnects soil to climate mitigation in 6.3.Hard
• 18Evaluating soil measurement methodsAssess sampling, laboratory analysis and field estimation.ApplicationA required critique of soil data.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating soil as a renewable resourceAssess formation rates against erosion rates.ApplicationApplies natural capital reasoning to soil.Very Hard
• 20Constructing an integrated soil systems analysisCombine composition, formation, function and degradation.ApplicationThe complete structure for a soil question.Very Hard
• 21Evaluating soil conservation techniquesAssess terracing, cover crops and reduced tillage.ApplicationConnects soil science to management practice.Very Hard
• 22Assessing soil degradation as a sustainability issueEvaluate consequences for food security and climate.ApplicationConnects soil to Chapters 5 and 6.Very Hard
• 23Evaluating soil carbon sequestration potentialAssess capacity, permanence and management requirements.ApplicationA contemporary mitigation evaluation.Very Hard
• 24Synthesis: soil systems, function and degradationIntegrate composition, formation and management into one framework.ApplicationA capstone model for soil questions.Very Hard

Easy — Foundations

• 1Agricultural land useDescribe the extent and distribution of farmed land.ApplicationThe context for every food production question.Easy
• 2Traditional and subsistence farming systemsDescribe low-input production primarily for household use.ApplicationOne end of the agricultural intensity spectrum.Easy
• 3Modern intensive farming systemsDescribe high-input high-output commercial production.ApplicationThe system responsible for most global output.Easy
• 4Comparing farming systemsContrast inputs, outputs, efficiency and sustainability.ApplicationThe most frequently set agricultural comparison.Easy
• 5Environmental impacts of intensive agricultureIdentify soil loss, pollution, biodiversity loss and emissions.ApplicationThe costs behind high productivity.Easy
• 6Soil conservation in agricultureDescribe terracing, contour ploughing, cover crops and windbreaks.ApplicationThe practical response to soil degradation.Easy

Medium — Applications

• 7Food security definedDescribe reliable access to sufficient safe nutritious food.ApplicationThe four-pillar definition examiners expect.Medium
• 8Factors influencing farming choicesIdentify climate, soil, economics, culture and policy.ApplicationExplains why farming differs between regions.Medium
• 9Alternative and regenerative agricultureDescribe organic, agroforestry and regenerative approaches.ApplicationThe named alternatives in the syllabus.Medium
• 10Technological innovation in agricultureDescribe precision farming, genetic modification and vertical farming.ApplicationThe technocentric response to food demand.Medium
• 11Sustainability of different dietsCompare land, water and emissions across dietary patterns.ApplicationConnects diet to trophic efficiency in 2.2.Medium
• 12Food distribution, waste and malnutritionDescribe loss in supply chains and unequal access.ApplicationExplains hunger despite sufficient global production.Medium

Hard — Structured IB Questions

• 13Analysing the energy efficiency of food systemsCompare energy inputs and food energy outputs.ApplicationThe core quantitative task in this topic.Hard
• 14Analysing land use requirements of different dietsQuantify land needed per unit of food energy.ApplicationConnects diet choice to land availability.Hard
• 15Analysing a named agricultural case studyExplain inputs, outputs and sustainability of a real system.ApplicationA case study examiners expect in detail.Hard
• 16Analysing the causes of food insecurity in a regionIdentify availability, access, utilisation and stability failures.ApplicationApplies the food security framework precisely.Hard
• 17Analysing the environmental cost of a food productTrace water, land and emissions through production.ApplicationA contemporary applied task.Hard
• 18Evaluating intensive against extensive farmingAssess yield, environmental cost and resilience.ApplicationThe central agricultural evaluation.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating genetic modification in agricultureAssess yield and resistance benefits against risks and equity.ApplicationA contested evaluation requiring balance.Very Hard
• 20Constructing an integrated sustainable food strategyCombine production, distribution, diet and waste measures.ApplicationThe complete structure for a food systems question.Very Hard
• 21Evaluating regenerative agricultureAssess soil and carbon benefits against yield and scale.ApplicationA contemporary evaluation examiners reward.Very Hard
• 22Assessing the sustainability of harvesting wild speciesEvaluate bushmeat and wild harvest against alternatives.ApplicationA named syllabus topic requiring careful judgement.Very Hard
• 23Evaluating dietary change as an environmental strategyAssess emissions reduction against cultural and economic barriers.ApplicationThe most impactful individual-level intervention.Very Hard
• 24Synthesis: agriculture, security and food system sustainabilityIntegrate production, environment and access into one framework.ApplicationA capstone model closing the whole of Chapter 5.Very Hard

Easy — Foundations

• 1Atmospheric compositionIdentify the major and trace gases of the atmosphere.ApplicationThe basis for understanding greenhouse effects.Easy
• 2Functions of the atmosphereDescribe temperature regulation, protection and gas supply.ApplicationExplains why atmospheric change matters.Easy
• 3Atmospheric layersDescribe troposphere, stratosphere and higher layers.ApplicationDistinguishes surface pollution from ozone processes.Easy
• 4Changes with altitudeExplain temperature, pressure and density variation with height.ApplicationExplains layer boundaries and vertical mixing.Easy
• 5The natural greenhouse effectDescribe absorption and re-emission of longwave radiation.ApplicationThe process making Earth habitable.Easy
• 6Greenhouse gasesIdentify carbon dioxide, methane, nitrous oxide and water vapour.ApplicationThe gases responsible for radiative forcing.Easy

Medium — Applications

• 7The enhanced greenhouse effectExplain intensification from increased greenhouse gas concentration.ApplicationThe mechanism of anthropogenic warming.Medium
• 8AlbedoDescribe surface reflectivity and its effect on energy balance.ApplicationThe key variable in ice-albedo feedback.Medium
• 9Atmospheric dynamics and energy balanceDescribe incoming and outgoing radiation budgets.ApplicationThe framework for analysing climate forcing.Medium
• 10Milankovitch cyclesDescribe orbital variations driving long-term climate change.ApplicationThe natural driver examiners expect named.Medium
• 11Hothouse Earth conditionsDescribe past periods of extreme global warmth.ApplicationThe palaeoclimate context for current change.Medium
• 12Atmospheric composition and the evolution of lifeExplain oxygenation and its biological consequences.ApplicationConnects atmosphere to biological history.Medium

Hard — Structured IB Questions

• 13Constructing an energy balance diagramDraw incoming, reflected and outgoing radiation flows.ApplicationA directly assessed diagram skill.Hard
• 14Analysing the greenhouse effect mechanismExplain wavelength-specific absorption step by step.ApplicationThe core explanatory task in this topic.Hard
• 15Analysing albedo feedbackExplain ice loss amplifying warming as positive feedback.ApplicationConnects atmosphere to feedback theory in 1.2.Hard
• 16Analysing Milankovitch cycle evidenceInterpret ice core data against orbital forcing.ApplicationConnects natural cycles to palaeoclimate data.Hard
• 17Comparing natural and anthropogenic forcingContrast timescales and magnitudes of each driver.ApplicationAddresses the most common climate misconception.Hard
• 18Evaluating evidence for the enhanced greenhouse effectAssess concentration, temperature and isotope evidence.ApplicationThe standard evaluation of attribution evidence.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating palaeoclimate proxy dataAssess resolution and uncertainty in ice core records.ApplicationA required critique of palaeoclimate evidence.Very Hard
• 20Constructing an integrated atmospheric systems analysisCombine composition, energy balance and forcing.ApplicationThe complete structure for an atmosphere question.Very Hard
• 21Evaluating water vapour as a feedback rather than forcingAssess its amplifying role in the climate system.ApplicationA precise conceptual point examiners reward.Very Hard
• 22Assessing hothouse Earth scenariosEvaluate palaeoclimate analogues for future warming.ApplicationConnects past climate to future projection.Very Hard
• 23Evaluating the role of aerosols in the energy balanceAssess cooling effects offsetting greenhouse warming.ApplicationA sophisticated point often omitted by candidates.Very Hard
• 24Synthesis: composition, energy balance and atmospheric functionIntegrate structure, radiation and forcing into one framework.ApplicationA capstone model for atmospheric questions.Very Hard

Easy — Foundations

• 1Causes of climate changeDistinguish natural and anthropogenic drivers of warming.ApplicationThe framework structuring every climate answer.Easy
• 2Anthropogenic emission sourcesIdentify energy, transport, industry, agriculture and land use.ApplicationLocates where mitigation must be targeted.Easy
• 3Methane sources and warming potentialDescribe agricultural, waste and fossil sources of methane.ApplicationExplains a high-impact short-lived greenhouse gas.Easy
• 4Land use change and emissionsExplain deforestation as both emission and sink loss.ApplicationConnects climate to biodiversity and carbon cycling.Easy
• 5Ecological impacts of climate changeDescribe range shifts, phenology change and coral bleaching.ApplicationThe biological consequences examiners expect.Easy
• 6Societal impacts of climate changeDescribe food, water, health and displacement consequences.ApplicationThe human consequences requiring policy response.Easy

Medium — Applications

• 7Sea level riseExplain thermal expansion and land ice melt contributions.ApplicationThe impact with the largest long-term consequences.Medium
• 8Climate monitoring and data collectionDescribe instrumental records, satellites and proxy data.ApplicationThe evidence base for climate conclusions.Medium
• 9Global climate modelsDescribe computer simulation of the climate system.ApplicationThe tool used for all future projections.Medium
• 10Critical thresholds and tipping pointsDescribe irreversible shifts in climate subsystems.ApplicationConnects climate to systems theory in 1.2.Medium
• 11Differences in responsibility for emissionsCompare historical and current emissions across countries.ApplicationThe equity basis of international negotiation.Medium
• 12Differences in vulnerability to impactsCompare exposure and adaptive capacity across regions.ApplicationConnects climate to environmental justice in 1.3.Medium

Hard — Structured IB Questions

• 13Interpreting climate data trendsAnalyse temperature, concentration and sea level records.ApplicationThe core quantitative task in this topic.Hard
• 14Analysing attribution of a specific eventExplain the link between warming and an extreme event.ApplicationA contemporary applied task examiners set.Hard
• 15Analysing a named tipping pointExplain the mechanism and consequences of a threshold crossing.ApplicationA case study examiners expect in detail.Hard
• 16Analysing emissions data by country and per capitaCompare total and per person responsibility.ApplicationThe distinction that transforms an equity argument.Hard
• 17Analysing climate impacts on a named ecosystemTrace warming effects through an ecological system.ApplicationConnects climate to Chapters 2 and 3.Hard
• 18Evaluating global climate modelsAssess resolution, feedback representation and uncertainty.ApplicationA required critique of climate projections.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating climate monitoring evidenceAssess record length, coverage and proxy reliability.ApplicationThe methodological critique of climate data.Very Hard
• 20Constructing an integrated climate impact analysisCombine drivers, mechanisms and consequences in one account.ApplicationThe complete structure for a climate question.Very Hard
• 21Evaluating differentiated responsibility argumentsAssess historical emissions against current capability.ApplicationThe central equity evaluation in climate policy.Very Hard
• 22Assessing vulnerability and adaptive capacityEvaluate why identical hazards produce different outcomes.ApplicationA justice-focused analysis examiners reward.Very Hard
• 23Evaluating uncertainty in climate projectionsAssess scenario dependence and confidence intervals.ApplicationPrevents overconfident use of single figures.Very Hard
• 24Synthesis: drivers, impacts and climate vulnerabilityIntegrate causes, consequences and equity into one framework.ApplicationA capstone model for climate change questions.Very Hard

Easy — Foundations

• 1Mitigation and adaptation distinguishedSeparate reducing causes from managing consequences.ApplicationThe distinction structuring every response answer.Easy
• 2International climate agreementsDescribe the framework and major agreements on emissions.ApplicationThe governance context for national action.Easy
• 3Nationally determined contributionsDescribe country-level emission reduction commitments.ApplicationThe mechanism behind current international policy.Easy
• 4DecarbonisationDescribe reducing carbon intensity of energy and industry.ApplicationThe central mitigation strategy.Easy
• 5Renewable energy transitionDescribe replacement of fossil fuels with low-carbon sources.ApplicationConnects climate policy to energy in 7.2.Easy
• 6Energy efficiency and demand reductionDescribe reducing energy required per unit of output.ApplicationThe cheapest mitigation option available.Easy

Medium — Applications

• 7Carbon pricing mechanismsDescribe taxes and emissions trading schemes.ApplicationThe main economic mitigation instrument.Medium
• 8Nature-based mitigation solutionsDescribe afforestation, wetland and soil carbon approaches.ApplicationConnects mitigation to Chapters 2, 3 and 5.Medium
• 9Adaptation strategiesIdentify flood defence, drought-resistant crops and relocation.ApplicationThe response where mitigation is insufficient.Medium
• 10Greenhouse gas emission scenariosDescribe projected pathways under differing policy assumptions.ApplicationThe basis of all long-term climate projection.Medium
• 11Geoengineering approachesDescribe solar radiation management and carbon dioxide removal.ApplicationThe intervention option named in the syllabus.Medium
• 12Challenges of climate interventionDescribe governance, side effects and termination risk.ApplicationThe critical framing for geoengineering evaluation.Medium

Hard — Structured IB Questions

• 13Analysing a mitigation strategy's emission reductionQuantify the effect of a specific measure.ApplicationThe core applied task in this topic.Hard
• 14Analysing the cost effectiveness of mitigation optionsCompare abatement cost per unit of emissions avoided.ApplicationDirects limited resources to the best measures.Hard
• 15Analysing adaptation needs for a named regionIdentify priority measures from vulnerability evidence.ApplicationConnects adaptation to vulnerability analysis in 6.2.Hard
• 16Comparing mitigation and adaptation prioritiesContrast timescale, cost and equity implications.ApplicationA frequently set climate policy comparison.Hard
• 17Analysing stakeholder perspectives on climate policyExplain positions of governments, industry and citizens.ApplicationConnects climate policy to value systems in 1.1.Hard
• 18Evaluating international climate agreementsAssess enforcement, ambition and participation.ApplicationA required critique of the governance framework.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating carbon pricing effectivenessAssess price levels, leakage and distributional effects.ApplicationThe standard evaluation of the economic instrument.Very Hard
• 20Constructing an integrated climate response strategyCombine mitigation, adaptation and governance measures.ApplicationThe complete structure for a climate policy question.Very Hard
• 21Evaluating geoengineering proposalsAssess effectiveness, risk, governance and moral hazard.ApplicationA demanding evaluation examiners reward highly.Very Hard
• 22Assessing equity in climate finance and responsibilityEvaluate support flows from high to low emitting countries.ApplicationConnects climate policy to justice in 1.3.Very Hard
• 23Evaluating nature-based solutionsAssess permanence, land competition and co-benefits.ApplicationBalances enthusiasm against ecological limits.Very Hard
• 24Synthesis: mitigation, adaptation and climate governanceIntegrate strategy, equity and feasibility into one framework.ApplicationA capstone model for climate response questions.Very Hard

Easy — Foundations

• 1Ultraviolet radiationDescribe UVA, UVB and UVC and their biological effects.ApplicationExplains why stratospheric ozone matters.Easy
• 2Stratospheric ozone formationDescribe the natural cycle of ozone creation and destruction.ApplicationThe equilibrium disrupted by human emissions.Easy
• 3The ozone layer functionDescribe absorption of harmful ultraviolet radiation.ApplicationThe protective service provided by the stratosphere.Easy
• 4ChlorofluorocarbonsDescribe their properties, uses and atmospheric persistence.ApplicationThe primary ozone-depleting substances.Easy
• 5Mechanism of ozone depletionExplain chlorine catalysed destruction of ozone molecules.ApplicationThe chemistry required for full marks.Easy
• 6Polar ozone lossExplain polar stratospheric clouds and springtime depletion.ApplicationExplains the concentrated Antarctic ozone hole.Easy

Medium — Applications

• 7Consequences of ozone depletionDescribe health, ecological and agricultural effects.ApplicationThe impacts justifying international action.Medium
• 8The Montreal ProtocolDescribe the agreement phasing out ozone depleting substances.ApplicationThe most successful environmental treaty.Medium
• 9Hydrofluorocarbons as replacementsDescribe substitutes and their greenhouse warming potential.ApplicationExplains the link between ozone and climate policy.Medium
• 10The Kigali AmendmentDescribe extension of the protocol to phase down replacements.ApplicationThe contemporary development in ozone governance.Medium
• 11Ozone recovery evidenceDescribe monitoring data showing stratospheric recovery.ApplicationThe measurable outcome of successful policy.Medium
• 12Tropospheric and stratospheric ozone distinguishedSeparate harmful surface ozone from protective stratospheric ozone.ApplicationA distinction examiners test in almost every session.Medium

Hard — Structured IB Questions

• 13Analysing ozone concentration dataInterpret monitoring records for depletion and recovery.ApplicationThe core quantitative task in this topic.Hard
• 14Analysing the ozone depletion mechanismExplain the catalytic cycle step by step.ApplicationThe explanatory task examiners set most often.Hard
• 15Analysing why depletion is greatest at the polesExplain the specific conditions enabling polar loss.ApplicationA frequently examined mechanism question.Hard
• 16Analysing the link between ozone and climate policyExplain how replacement gases affect warming.ApplicationConnects 6.4 directly to Chapter 6 climate content.Hard
• 17Comparing ozone and climate governance outcomesContrast the success of each international response.ApplicationA comparison examiners reward highly.Hard
• 18Evaluating the Montreal ProtocolAssess design features explaining its effectiveness.ApplicationThe standard evaluation of successful governance.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating ozone monitoring evidenceAssess measurement methods and natural variability.ApplicationA required critique of atmospheric data.Very Hard
• 20Constructing an integrated ozone analysisCombine chemistry, consequences and governance in one account.ApplicationThe complete structure for an ozone question.Very Hard
• 21Evaluating the transferability of the Montreal modelAssess whether its approach could work for climate.ApplicationA demanding conceptual evaluation.Very Hard
• 22Assessing remaining threats to the ozone layerEvaluate illegal emissions and unregulated substances.ApplicationA contemporary application examiners reward.Very Hard
• 23Evaluating equity provisions in the Montreal ProtocolAssess differentiated timetables and financial support.ApplicationConnects ozone governance to justice in 1.3.Very Hard
• 24Synthesis: ozone, protection and environmental governanceIntegrate chemistry, impact and policy into one framework.ApplicationA capstone model closing the whole of Chapter 6.Very Hard

Easy — Foundations

• 1Natural capital definedDescribe natural resources that produce a flow of goods and services.ApplicationThe economic framing of the environment in ESS.Easy
• 2Natural incomeDescribe the sustainable yield derived from natural capital.ApplicationThe flow that may be harvested without depletion.Easy
• 3Renewable and non-renewable resourcesDistinguish resources by their replenishment capacity.ApplicationThe classification structuring every resource answer.Easy
• 4Replenishable resourcesDescribe resources restored by physical processes.ApplicationThe intermediate category examiners expect distinguished.Easy
• 5Ecosystem goods and servicesIdentify provisioning, regulating, supporting and cultural services.ApplicationThe framework for valuing natural capital.Easy
• 6Valuation of natural resourcesDescribe market and non-market approaches to valuation.ApplicationExplains why environmental value is often ignored.Easy

Medium — Applications

• 7Difficulties in environmental valuationExplain intangible, aesthetic and intrinsic value problems.ApplicationThe central critique of monetary valuation.Medium
• 8Dynamic nature of natural capitalExplain how technology and culture change what counts as a resource.ApplicationExplains why resource definitions shift over time.Medium
• 9Sustainable resource useDescribe harvesting within regenerative capacity.ApplicationApplies sustainability criteria to resource decisions.Medium
• 10Unsustainable exploitation of renewable resourcesExplain harvesting exceeding replacement rates.ApplicationExplains why renewable resources can still be exhausted.Medium
• 11Environmental impact assessmentDescribe evaluation of a project's environmental consequences.ApplicationThe main regulatory tool for development decisions.Medium
• 12Natural resource securityDescribe reliable access to resources over time.ApplicationConnects resource management to national policy.Medium

Hard — Structured IB Questions

• 13Classifying resources in a described scenarioPlace resources correctly by renewability and use.ApplicationThe core applied task in this topic.Hard
• 14Analysing the sustainability of a resource use patternCompare extraction rates with regeneration rates.ApplicationApplies natural capital reasoning quantitatively.Hard
• 15Analysing ecosystem services for a named ecosystemIdentify and categorise the services provided.ApplicationConnects valuation to specific ecosystems.Hard
• 16Analysing an environmental impact assessmentEvaluate the scope and conclusions of an assessment.ApplicationA practical applied task examiners set.Hard
• 17Analysing changing resource value over timeExplain how technology altered the status of a resource.ApplicationDemonstrates the dynamic nature of natural capital.Hard
• 18Evaluating monetary valuation of ecosystem servicesAssess decision-making usefulness against ethical objections.ApplicationThe central evaluation in this topic.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating environmental impact assessment as a toolAssess scope, independence and enforcement.ApplicationA required critique of the regulatory process.Very Hard
• 20Constructing an integrated resource management strategyCombine valuation, regulation and sustainable yield.ApplicationThe complete structure for a resource question.Very Hard
• 21Evaluating value system influence on resource decisionsAssess how worldviews shape management choices.ApplicationConnects Chapter 7 back to Chapter 1.Very Hard
• 22Assessing resource security and geopolitical riskEvaluate dependence on imported critical resources.ApplicationA contemporary application examiners expect.Very Hard
• 23Evaluating intergenerational equity in resource useAssess obligations to future users of natural capital.ApplicationA sustainability principle from 1.3 applied precisely.Very Hard
• 24Synthesis: capital, income and resource sustainabilityIntegrate valuation, yield and governance into one framework.ApplicationA capstone model for resource questions.Very Hard

Easy — Foundations

• 1Classification of energy sourcesDistinguish renewable, non-renewable and replenishable energy.ApplicationThe framework structuring every energy answer.Easy
• 2Fossil fuel energy sourcesDescribe coal, oil and gas formation, use and consequences.ApplicationThe dominant global energy sources.Easy
• 3Fossil fuel reservesDescribe proven reserves and reserve-to-production ratios.ApplicationQuantifies the finite nature of fossil energy.Easy
• 4Nuclear powerDescribe fission energy generation and its characteristics.ApplicationA low-carbon but controversial energy source.Easy
• 5Nuclear waste and safety concernsDescribe long-lived waste and accident risk.ApplicationThe counterweight in every nuclear evaluation.Easy
• 6Solar and wind energyDescribe generation, capacity factors and intermittency.ApplicationThe fastest growing renewable sources.Easy

Medium — Applications

• 7Hydroelectric powerDescribe generation and its ecological consequences.ApplicationConnects energy to water systems in 4.1.Medium
• 8Biomass and biofuel energyDescribe energy from organic material and its trade-offs.ApplicationConnects energy to land use in Chapter 5.Medium
• 9Patterns of energy consumptionDescribe variation in use across countries and over time.ApplicationExplains unequal contributions to emissions.Medium
• 10Factors influencing energy choicesIdentify availability, cost, politics, culture and technology.ApplicationExplains why countries adopt different energy mixes.Medium
• 11Energy storage technologiesDescribe batteries and other storage addressing intermittency.ApplicationThe key enabler of high renewable penetration.Medium
• 12Energy security and conservationDescribe reliable affordable supply and demand reduction.ApplicationThe policy objective guiding energy decisions.Medium

Hard — Structured IB Questions

• 13Interpreting energy mix dataAnalyse the composition of a country's energy supply.ApplicationThe core applied task in this topic.Hard
• 14Analysing energy consumption trendsInterpret consumption data against development level.ApplicationConnects energy to human development.Hard
• 15Analysing the energy choices of a named countryExplain the mix using availability, politics and economics.ApplicationA case study examiners expect in detail.Hard
• 16Comparing energy sources on multiple criteriaContrast emissions, cost, reliability and land use.ApplicationThe most frequently set energy comparison.Hard
• 17Analysing intermittency and storage requirementsExplain the technical challenge of variable generation.ApplicationA contemporary technical point examiners reward.Hard
• 18Evaluating nuclear powerAssess low emissions against waste, cost and risk.ApplicationThe standard evaluation of a contested source.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating renewable energy transition feasibilityAssess materials, land, storage and grid requirements.ApplicationPrevents uncritical optimism about renewables.Very Hard
• 20Constructing an integrated energy strategyCombine sources, storage, efficiency and security.ApplicationThe complete structure for an energy question.Very Hard
• 21Evaluating biofuels as a sustainable energy sourceAssess land competition and net emissions.ApplicationA required critique of a widely promoted option.Very Hard
• 22Assessing energy poverty and access equityEvaluate unequal access to reliable modern energy.ApplicationConnects energy to justice in 1.3.Very Hard
• 23Evaluating energy conservation against supply expansionJudge demand reduction as an alternative to new generation.ApplicationThe cheapest and most overlooked strategy.Very Hard
• 24Synthesis: energy sources, security and sustainabilityIntegrate mix, security and environmental cost into one framework.ApplicationA capstone model for energy questions.Very Hard

Easy — Foundations

• 1Types of solid wasteIdentify municipal, industrial, hazardous and electronic waste.ApplicationThe classification structuring every waste answer.Easy
• 2Sources of solid wasteDescribe household, commercial, industrial and construction sources.ApplicationLocates where reduction efforts should target.Easy
• 3Waste generation patternsDescribe variation in waste volume with income and development.ApplicationExplains unequal global waste production.Easy
• 4Environmental consequences of wasteDescribe leachate, emissions, litter and habitat damage.ApplicationThe ecological case for waste management.Easy
• 5Social consequences of wasteDescribe health, amenity and environmental justice impacts.ApplicationConnects waste to justice in 1.3.Easy
• 6Landfill disposalDescribe engineered burial and its management requirements.ApplicationThe most common disposal method globally.Easy

Medium — Applications

• 7Incineration and energy recoveryDescribe combustion with heat and power generation.ApplicationConnects waste management to energy in 7.2.Medium
• 8Composting and anaerobic digestionDescribe biological treatment of organic waste.ApplicationThe main route for the largest waste fraction.Medium
• 9Recycling systemsDescribe collection, sorting and reprocessing of materials.ApplicationThe most widely promoted waste strategy.Medium
• 10The waste hierarchyDescribe prevention, reuse, recycling, recovery and disposal.ApplicationThe framework examiners expect applied.Medium
• 11Circular economy approaches to wasteDescribe designing out waste through material loops.ApplicationConnects waste to economic models in 1.3.Medium
• 12Electronic waste and transboundary movementDescribe export of hazardous waste between countries.ApplicationA contemporary environmental justice issue.Medium

Hard — Structured IB Questions

• 13Applying the waste hierarchy to a scenarioJustify measures at each level of the hierarchy.ApplicationThe core applied task in this topic.Hard
• 14Analysing waste composition dataInterpret waste stream data to target interventions.ApplicationDirects strategy at the largest fractions.Hard
• 15Analysing the life cycle of a productTrace material and energy flows from extraction to disposal.ApplicationA directly assessed analytical skill.Hard
• 16Comparing disposal methodsContrast landfill, incineration and recycling on cost and impact.ApplicationThe most frequently set waste comparison.Hard
• 17Analysing the consequences of a waste management failureExplain environmental and social effects at a named site.ApplicationA case study examiners expect in detail.Hard
• 18Evaluating recycling as a waste strategyAssess energy cost, contamination and market limitations.ApplicationA required critique of the default solution.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating incineration with energy recoveryAssess emissions and residues against landfill diversion.ApplicationA contested evaluation requiring balance.Very Hard
• 20Constructing an integrated waste management strategyCombine prevention, treatment and disposal measures.ApplicationThe complete structure for a waste question.Very Hard
• 21Evaluating circular economy approaches to wasteAssess material recovery limits and energy requirements.ApplicationA contemporary evaluation examiners reward.Very Hard
• 22Assessing environmental justice in waste disposalEvaluate siting of facilities and waste export patterns.ApplicationConnects waste to justice explicitly.Very Hard
• 23Evaluating waste reduction against improved disposalJudge prevention as the priority intervention.ApplicationApplies the hierarchy as an evaluative principle.Very Hard
• 24Synthesis: waste, management and material sustainabilityIntegrate generation, treatment and prevention into one framework.ApplicationA capstone model closing the whole of Chapter 7.Very Hard

Easy — Foundations

• 1Human population changeDescribe historical and projected trends in global population.ApplicationThe pressure underlying every environmental issue.Easy
• 2Crude birth and death ratesCalculate and interpret rates per thousand population.ApplicationThe basic demographic measures examiners test.Easy
• 3Natural increase rateCalculate population change excluding migration.ApplicationThe core measure of population growth.Easy
• 4Total fertility rateDescribe average births per woman and replacement level.ApplicationThe strongest predictor of long-term population change.Easy
• 5Doubling timeCalculate the time for a population to double in size.ApplicationA routinely examined quantitative task.Easy
• 6The demographic transition modelDescribe the five stages of demographic change.ApplicationThe framework structuring every population answer.Easy

Medium — Applications

• 7Population pyramidsDescribe age and sex structure diagrams.ApplicationThe diagram examiners expect interpreted accurately.Medium
• 8Dependency ratiosCalculate dependent population relative to working population.ApplicationExplains economic pressure from age structure.Medium
• 9Population momentumExplain continued growth despite falling fertility.ApplicationExplains why growth continues after policy change.Medium
• 10Approaches to managing population growthDescribe education, healthcare, family planning and policy.ApplicationThe intervention toolkit examiners expect.Medium
• 11Population growth and environmental stressExplain resource demand and pollution consequences.ApplicationThe central link in this topic.Medium
• 12Environmental migrationDescribe movement driven by environmental degradation.ApplicationA contemporary issue named in the syllabus.Medium

Hard — Structured IB Questions

• 13Calculating demographic indicatorsCompute rates, ratios and doubling time from data.ApplicationThe core quantitative task in this topic.Hard
• 14Interpreting a population pyramidInfer stage, dependency and future trends from structure.ApplicationA directly assessed practical skill.Hard
• 15Analysing a country's position in the transition modelJustify placement using demographic evidence.ApplicationThe core applied task in population questions.Hard
• 16Analysing the IPAT relationshipExplain impact as population, affluence and technology.ApplicationThe framework linking population to environmental impact.Hard
• 17Analysing the effect of a population policyTrace demographic and environmental consequences.ApplicationA case study examiners expect in detail.Hard
• 18Evaluating the demographic transition modelAssess its Eurocentric basis and predictive limits.ApplicationA required critique of the central model.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating population policiesAssess effectiveness, ethics and unintended consequences.ApplicationThe standard evaluation in this topic.Very Hard
• 20Constructing an integrated population analysisCombine structure, trends, policy and environmental pressure.ApplicationThe complete structure for a population question.Very Hard
• 21Evaluating population against consumption as a driverAssess whether numbers or affluence dominate impact.ApplicationThe central debate in population and environment.Very Hard
• 22Assessing environmental migration as a policy challengeEvaluate recognition, rights and receiving country capacity.ApplicationA contemporary justice issue examiners reward.Very Hard
• 23Evaluating ageing population consequencesAssess economic, social and environmental implications.ApplicationApplies demography to high-income contexts.Very Hard
• 24Synthesis: population, consumption and environmental pressureIntegrate demography, impact and policy into one framework.ApplicationA capstone model for population questions.Very Hard

Easy — Foundations

• 1Characteristics of urban areasDescribe density, land use and infrastructure features.ApplicationThe defining features analysed in urban questions.Easy
• 2UrbanisationDescribe the increasing proportion of population living in cities.ApplicationThe dominant demographic trend of the century.Easy
• 3Drivers of urbanisationIdentify push and pull factors driving rural to urban movement.ApplicationExplains the pace and pattern of city growth.Easy
• 4Urban expansion and sprawlDescribe low-density outward growth of built areas.ApplicationThe land use consequence of unplanned growth.Easy
• 5Urban ecological footprintDescribe the resource demand of a city beyond its boundary.ApplicationQuantifies urban dependence on wider systems.Easy
• 6The urban heat island effectExplain elevated city temperatures from surfaces and energy use.ApplicationA measurable urban environmental problem.Easy

Medium — Applications

• 7Urban planning approachesDescribe zoning, density and transport planning tools.ApplicationThe intervention toolkit for city environments.Medium
• 8Ecological approaches to city designDescribe green space, corridors and ecosystem integration.ApplicationConnects urban planning to ecology.Medium
• 9Urban sustainability modelsDescribe compact city and transit-oriented development.ApplicationThe named models in the syllabus.Medium
• 10Green architectureDescribe building design reducing energy and resource use.ApplicationThe building-scale sustainability intervention.Medium
• 11Urban water and waste systemsDescribe supply, drainage and waste infrastructure demands.ApplicationConnects urban systems to Chapters 4 and 7.Medium
• 12Urban agriculture and food systemsDescribe food production within and near cities.ApplicationConnects urban planning to food security in 5.2.Medium

Hard — Structured IB Questions

• 13Analysing an urban system using systems diagramsDraw inputs, storages and outputs for a city.ApplicationApplies systems thinking from 1.2 to cities.Hard
• 14Calculating an urban ecological footprintCompute footprint from city consumption data.ApplicationA routinely examined quantitative task.Hard
• 15Analysing the urban heat island in a named cityExplain causes and consequences with evidence.ApplicationA case study examiners expect in detail.Hard
• 16Analysing the environmental effects of sprawlExplain habitat loss, transport emissions and infrastructure cost.ApplicationThe core applied task in urban questions.Hard
• 17Comparing compact and dispersed urban formsContrast resource use, transport and land consumption.ApplicationThe most frequently set urban comparison.Hard
• 18Evaluating urban sustainability modelsAssess feasibility, cost and social acceptability.ApplicationThe standard evaluation in this topic.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating green architectureAssess emissions reduction against construction cost.ApplicationA balanced evaluation examiners reward.Very Hard
• 20Constructing an integrated sustainable city strategyCombine planning, transport, buildings and green space.ApplicationThe complete structure for an urban question.Very Hard
• 21Evaluating urban green space provisionAssess ecological, health and cooling benefits.ApplicationConnects urban planning to multiple benefits.Very Hard
• 22Assessing environmental justice in urban planningEvaluate unequal access to green space and clean air.ApplicationConnects urban systems to justice in 1.3.Very Hard
• 23Evaluating cities as solutions rather than problemsAssess density as an efficiency advantage.ApplicationA counterintuitive argument examiners reward.Very Hard
• 24Synthesis: urbanisation, planning and urban sustainabilityIntegrate growth, design and resource use into one framework.ApplicationA capstone model for urban questions.Very Hard

Easy — Foundations

• 1Sources of urban air pollutionIdentify transport, industry, heating and construction sources.ApplicationThe classification structuring every air quality answer.Easy
• 2Primary and secondary pollutantsDistinguish directly emitted from atmospherically formed pollutants.ApplicationA distinction examiners test precisely.Easy
• 3Major urban air pollutantsIdentify particulates, nitrogen oxides, sulfur dioxide and ozone.ApplicationThe pollutants monitored in every city.Easy
• 4Particulate matterDescribe size fractions and their health consequences.ApplicationThe pollutant with the greatest health burden.Easy
• 5Tropospheric ozone formationExplain photochemical reaction of nitrogen oxides and hydrocarbons.ApplicationThe mechanism behind photochemical smog.Easy
• 6Photochemical smogDescribe conditions producing and trapping urban smog.ApplicationA named syllabus topic examined regularly.Easy

Medium — Applications

• 7Thermal inversionsExplain trapping of pollutants beneath a warm air layer.ApplicationExplains severe pollution episodes in specific cities.Medium
• 8Acid depositionDescribe formation and deposition of acidic pollutants.ApplicationA named syllabus topic with transboundary effects.Medium
• 9Ecological impacts of acid depositionDescribe effects on soils, forests and freshwater systems.ApplicationConnects air pollution to Chapters 4 and 5.Medium
• 10Health impacts of urban air pollutionDescribe respiratory, cardiovascular and mortality effects.ApplicationThe human cost driving air quality policy.Medium
• 11Air quality monitoring and standardsDescribe measurement methods and guideline thresholds.ApplicationThe evidence base for air quality management.Medium
• 12Pollution management strategies for airIdentify prevention, control and clean-up interventions.ApplicationThe three-level management model applied to air.Medium

Hard — Structured IB Questions

• 13Interpreting air quality dataAnalyse pollutant concentration data against standards.ApplicationThe core quantitative task in this topic.Hard
• 14Analysing a photochemical smog episodeExplain formation conditions and consequences at a named city.ApplicationA case study examiners expect in detail.Hard
• 15Analysing acid deposition pathwaysTrace pollutants from source to distant deposition.ApplicationExplains transboundary pollution disputes.Hard
• 16Applying the pollution management model to air qualityJustify measures at each intervention level.ApplicationThe structure examiners reward most highly.Hard
• 17Analysing the effect of a transport policy on air qualityTrace emission changes following an intervention.ApplicationConnects urban policy to measurable outcomes.Hard
• 18Evaluating air quality standardsAssess threshold levels against health evidence.ApplicationA required critique of regulatory limits.Hard

Very Hard — Integrated HL Challenge

• 19Evaluating urban transport interventionsAssess congestion charging, low emission zones and public transport.ApplicationThe standard evaluation of urban air policy.Very Hard
• 20Constructing an integrated air quality strategyCombine prevention, control and monitoring measures.ApplicationThe complete structure for an air pollution question.Very Hard
• 21Evaluating international cooperation on acid depositionAssess agreements addressing transboundary pollution.ApplicationConnects air pollution to governance in 6.4.Very Hard
• 22Assessing environmental justice in air pollution exposureEvaluate unequal exposure across income groups.ApplicationConnects air quality to justice in 1.3.Very Hard
• 23Evaluating the co-benefits of air and climate policyAssess emission reductions serving both objectives.ApplicationA sophisticated synthesis examiners reward highly.Very Hard
• 24Synthesis: urban air quality, health and managementIntegrate sources, effects and interventions into one framework.ApplicationA capstone model closing the whole course.Very Hard