IB Environmental Systems and Societies (ESS) 2025 Study Guide – Extended Essays

A comprehensive set of vocabulary flashcards covering key concepts in IB Environmental Systems and Societies for revision.

Ecological Footprint

A measurement of human demand on Earth's ecosystems, representing the land and water area required to produce resources and absorb waste.

Biocapacity

The capacity of an area to generate renewable resources and absorb waste, especially carbon dioxide.

Sustainability

The ability of a system to maintain ecological balance by operating within environmental limits.

Sustainable Development Goals (SDGs)

Seventeen interdependent global goals adopted by the United Nations to address social, economic, and environmental challenges by 2030.

Planetary Boundaries

A framework identifying nine critical Earth system processes and the thresholds that should not be crossed to maintain stability.

Doughnut Economics

An economic model that integrates planetary boundaries with social foundations, ensuring basic human needs are met within ecological limits.

Carrying Capacity

The maximum population size that an environment can sustain without long-term degradation.

Exponential Growth (J-curve)

Population growth in environments with abundant resources, leading to rapid increases that are ultimately unstable.

Logistic Growth (S-curve)

Population growth that stabilizes as resource availability limits growth, reaching the carrying capacity.

Trophic Levels

Layers in a food chain that depict feeding relationships, including primary producers, consumers, and decomposers.

Gross Primary Productivity (GPP)

The total energy captured by producers in an ecosystem.

Net Primary Productivity (NPP)

The energy captured by producers minus energy lost through respiration.

Biogeochemical Cycles

Processes that recycle essential elements like carbon and nitrogen through the environment.

Carbon Sink

Natural reservoirs that absorb more carbon than they emit, such as forests and oceans.

Nitrogen Fixation

The process by which certain bacteria convert atmospheric nitrogen into forms usable by plants.

Cladistics

A method of classifying organisms based on their evolutionary relationships and common ancestry.

Community Structure

The complex arrangement of species populations interacting within an ecosystem.

Keystone Species

Species that have a disproportionately large effect on their environment, critical for maintaining the structure of the ecosystem.

Fossil Fuels

Natural substances formed from ancient organic matter that serve as significant carbon sources when burned.

Negative Feedback Mechanisms

Processes that counteract changes in population size, helping to stabilize ecosystems.

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem, encompassing genetic, species, and ecosystem diversity.

Ecosystem Services

The many benefits that nature provides to humanity, such as clean air and water, pollination of crops, and regulation of climate.

Ecological Succession

The process of change in the species structure of an ecological community over time, often following a disturbance.

Limiting Factors

Environmental conditions that restrict the growth, abundance, or distribution of an organism or population within an ecosystem.

Biomes

Large, naturally occurring communities of flora and fauna occupying a major habitat, such as forest or tundra.

Greenhouse Effect

The process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without its atmosphere.

Renewable Resources

Natural resources that are replenished naturally over a relatively short period, such as solar energy, wind energy, and biomass.