100+ Free IB ESS SL Practice Questions

1: Foundations of ESS

Systems approach (open, closed, isolated systems), first and second laws of thermodynamics applied to environmental systems, energy and matter transfers and transformations, positive vs negative feedback loops with environmental examples, environmental value systems (anthropocentric, ecocentric, technocentric), Brundtland (1987) definition of sustainable development

2: Ecosystems and Ecology

Biotic vs abiotic factors, community vs population vs ecosystem vs biome, trophic levels (producers, primary/secondary/tertiary consumers), food chains and food webs, pyramids of numbers/biomass/energy, GPP vs NPP, secondary productivity, 10% energy transfer rule, water/carbon/nitrogen/phosphorus cycles, primary vs secondary succession, climax community, zonation, sampling (quadrats, line and belt transects, Lincoln Index), Simpson's diversity index

3: Biodiversity and Conservation

Genetic, species and ecosystem diversity, species richness vs evenness, ecological/economic/ethical/aesthetic/cultural value of biodiversity, Myers (2000) and Conservation International biodiversity hotspots, habitat loss/overexploitation/pollution/invasive species/climate change threats, IUCN Red List categories, CITES, in-situ conservation (national parks, MPAs, Ramsar, UNESCO MAB biosphere reserves) vs ex-situ (zoos, Svalbard and Kew seed banks, botanic gardens, captive breeding), flagship/keystone/umbrella species

4: Water

Hydrological cycle, thermohaline circulation, water demand and supply, surface water/groundwater/glaciers/desalination, agricultural/industrial/domestic uses, transboundary disputes (Nile, Mekong, Jordan), eutrophication causes (fertiliser runoff) and effects (algal bloom, dead zones), BOD biological oxygen demand, aquatic food production sustainability, MSY maximum sustainable yield, aquaculture, bycatch, Aral Sea, Three Gorges Dam, Pacific gyre plastic patch

5: Soil and Terrestrial Food Production

Soil composition (mineral/organic/water/air), A/B/C horizons, sandy/clay/loam soil types, degradation (erosion, compaction, salination, contamination), conservation (terracing, agroforestry, crop rotation, contour ploughing, cover crops), subsistence vs commercial and intensive vs extensive systems, arable vs pastoral, Green Revolution and GM crops, meat industry impacts, food waste, food security

6: Atmospheric Systems

Troposphere and stratosphere structure, stratospheric ozone formation (O2 to 2O to O3), CFC catalytic destruction, Montreal Protocol 1987, Antarctic ozone hole and recovery projections, tropospheric primary (SO2, NOx, CO, PM10/PM2.5, VOCs) vs secondary (acid rain, ground-level ozone, smog) pollutants, sources (vehicles, industry, agriculture), health/ecosystem/building effects, management (emissions standards, catalytic converters, scrubbers, electric vehicles)

7: Climate Change and Energy

Natural vs enhanced greenhouse effect, GHGs (CO2, CH4, N2O, water vapour, CFCs) and global warming potential, fossil fuel/deforestation/agriculture sources, evidence (temperature records, ice cores, glacier retreat, sea level), impacts (sea level rise, extreme weather, biodiversity, agriculture, ocean acidification), Kyoto 1997, Paris 2015 1.5C target, IPCC, COP, energy security, non-renewable (fossil fuels, nuclear) vs renewable (solar, wind, hydro, geothermal, biomass, wave, tidal), energy efficiency

8: Human Systems and Resource Use

Demographic transition model stages, youthful/mature/ageing population pyramids, ecological footprint (MEDC vs LEDC), biocapacity, solid domestic waste (landfill methane, incineration, recycling, composting), e-waste, circular vs linear economy, environmental impact assessment (EIA), Rockstrom planetary boundaries, Costa Rica and Galapagos ecotourism, sustainable urban planning