June exam CH1-CH4.2

IB ESS SL Key Definitions (Ch. 1 - 4.2)

Chapter 1: The Environment and Society

• Environment: All living and non-living things interacting in a particular area.

• System: A set of interrelated parts working together through inputs, processes, and outputs.

• Sustainability: Using resources in a way that meets current needs without compromising future generations.

• Natural Capital: Natural resources and ecosystems that provide goods and services.

• Environmental Value System (EVS): A world view or paradigm shaping how people perceive and evaluate environmental issues.

• Ecological Footprint: The area of land and water required to sustainably provide resources and absorb waste.

Chapter 2: Ecosystems and Ecology

• Ecosystem: A community of living organisms and their non-living environment interacting as a system.

• Biotic Factors: Living components of an ecosystem (plants, animals, bacteria).

• Abiotic Factors: Non-living components (water, soil, temperature).

• Niche: The role or function of an organism within an ecosystem.

• Population: Group of organisms of the same species living in a particular area.

• Community: All populations of different species living and interacting in an area.

• Producer (Autotroph): Organisms that produce their own food through photosynthesis.

• Consumer (Heterotroph): Organisms that obtain energy by consuming other organisms.

• Decomposer: Organisms that break down dead material and recycle nutrients.

• Food Chain: A linear sequence showing who eats whom.

• Food Web: A network of interconnected food chains.

• Biomass: Total mass of living organisms in a given area.

• Productivity: Rate of production of biomass.

• Gross Primary Productivity (GPP): Total energy captured by producers.

• Net Primary Productivity (NPP): Energy remaining after producers use energy for respiration (NPP = GPP - respiration).

• Energy Flow: Transfer of energy through trophic levels in an ecosystem (always decreases due to the 10% rule).

• Trophic Level: Position an organism occupies in a food chain/web.

Chapter 3: Biodiversity and Conservation

• Biodiversity: The variety of life in all its forms and levels.

• Genetic Diversity: Variety of genes within a species.

• Species Diversity: Number of different species in an ecosystem.

• Ecosystem Diversity: Variety of ecosystems within a region.

• Endemic Species: Species native to and found only within a specific area.

• Invasive Species: Non-native species that cause harm to the environment.

• Conservation: Protection and management of biodiversity to prevent extinction.

• Sustainable Yield: Harvesting resources at a rate that does not exceed regeneration.

• Indicator Species: Species that signal the health of an ecosystem.

• IUCN Red List: International list categorizing species according to extinction risk.

• Habitat Fragmentation: Breaking of habitats into smaller, isolated patches.

Chapter 4: Pollution Management (Up to 4.2)

• Pollution: Introduction of harmful substances or products into the environment.

• Point Source Pollution: Pollution from a single, identifiable source.

• Non-Point Source Pollution: Pollution from diffuse sources, not easily traced.

• Biodegradable Pollutant: Pollutant that can be broken down naturally.

• Non-biodegradable Pollutant: Pollutant that does not break down easily.

• Acid Deposition: Acidic pollutants falling to the ground as wet or dry deposition.

• Eutrophication: Excess nutrients (mainly nitrogen and phosphorus) causing algal blooms and oxygen depletion.

• Thermal Pollution: Release of heated water or air causing changes in temperature.

• Bioaccumulation: Build-up of substances, like pesticides, in an organism.

• Biomagnification: Increase in concentration of a pollutant as it moves up the food chain.

• Primary Pollutant: Pollutant emitted directly from a source.

• Secondary Pollutant: Pollutant formed by chemical reactions in the atmosphere.

• Mitigation: Actions taken to reduce or prevent pollution.

• Remediation: Cleaning up and restoring polluted environments.

Case studies

Absolutely, Steph! I’ll make sure each case study has the key IB ESS requirements for a case study:

• Background/context

• Causes (human/natural where relevant)

• Impacts on environment and people

• Responses (management, policy, human intervention)

• Evaluation/why it’s important

Here’s a complete IB-style case study for each topic example, covering all these points clearly:

IB ESS Case Studies (Topics 1–4) — Full IB Requirements

🔵 Topic 1: Environmental Movement — Chernobyl Nuclear Disaster (1986)

Background:

• Nuclear power plant in Ukraine (then USSR). Safety test caused reactor explosion.

Causes:

• Human error during poorly designed safety test.

Impacts:

• Released radioactive material → severe environmental contamination.

• Long-term health issues (cancers) in surrounding populations.

• Forest and wildlife contamination (mutations, deaths).

Responses:

• Worldwide reviews of nuclear safety protocols.

• Anti-nuclear protests and campaigns increased globally.

• Exclusion zone created (~30 km radius), still uninhabitable.

Evaluation:

• Showed risks of nuclear power and transboundary pollution.

• Raised awareness of ecosystem vulnerability to industrial disasters.

• Major milestone in environmental activism.

🟢 Topic 2: DDT and Silent Spring (Rachel Carson, 1962)

Background:

• Widespread use of DDT pesticide post-WWII to kill agricultural pests.

Causes:

• Chemical pesticide overuse in farming.

Impacts:

• Biomagnification harmed birds (eggshell thinning → population decline).

• Ecosystem imbalance by killing insects, affecting food webs.

• Human health concerns emerged.

Responses:

• Public outcry after Silent Spring book exposed impacts.

• US banned DDT in 1972; many other countries followed.

• Development of safer pest management methods.

Evaluation:

• Sparked modern environmentalism focused on chemical pollution.

• Example of how human actions can disrupt ecosystems.

• Key turning point for environmental legislation.

🟡 Topic 3: Endangered Species — Koala (Australia)

Background:

• Iconic Australian marsupial reliant on eucalyptus forests.

Causes:

• Habitat loss due to urban expansion and logging.

• Increased frequency of bushfires worsened by climate change.

Impacts:

• Population declines; some local extinctions.

• Reduced genetic diversity threatens long-term survival.

• Social and economic impact on ecotourism.

Responses:

• Habitat protection laws and conservation zones.

• Koala hospitals and rehabilitation centers.

• Community-led tree planting and wildlife corridors.

Evaluation:

• Highlights importance of habitat conservation.

• Shows how combined human and natural factors threaten species.

• Demonstrates success potential of targeted conservation.

🔴 Topic 4: Water Conflict — Nile River Dispute (Egypt, Ethiopia, Sudan)

Background:

• Nile River is the world’s longest, crucial to millions.

Causes:

• Ethiopia’s construction of Grand Ethiopian Renaissance Dam (GERD).

• Egypt’s fear of reduced Nile water flow, vital for agriculture and drinking.

Impacts:

• Tensions risk regional instability.

• Potential water shortages in Egypt.

• Ethiopia expects energy generation for development.

Responses:

• Diplomatic talks mediated by African Union and UN.

• Calls for cooperative water sharing agreements.

• Regional efforts toward sustainable water management.

Evaluation:

• Example of complex interplay of development and resource scarcity.

• Shows transboundary water management challenges.

• Emphasizes need for cooperation in shared ecosystems.