IB ESS Flashcards
Key IB ESS Terms, Concepts, and Applications
Flashcards built around the 2026 IB ESS syllabus. Each deck is organized by topic and covers key terms, core concepts, practical skills, and HL lens applications for that area. Study one topic at a time, shuffle for mixed practice, and track what you’ve mastered and aligned to the 2026 syllabus. SL and HL content included.
Topic 1: Foundation
Environmental perspectives and value systems — the range of viewpoints that shape how individuals and societies respond to environmental issues. Systems thinking, including open and closed systems, stores, flows and transfers, transformations, equilibrium, steady-state, feedback loops, tipping points, and resilience. Systems models and diagrams. Sustainability concepts including carrying capacity, planetary boundaries, ecological footprints, natural capital, and sustainability models, with environmental justice and circular economy as applications within the wider sustainability framework. This topic builds the conceptual framework that underpins the entire course.
Topic 2: Ecology
The organization of life from individuals and populations to communities and ecosystems. Classification and taxonomy, ecological niches, population dynamics, population growth and carrying capacity, and factors affecting population size and distribution. Species interactions including predation, competition, mutualism, and parasitism. Energy flow, productivity and ecological pyramids. Biogeochemical cycles including carbon, nitrogen and phosphorus. Climate, biomes and atmospheric circulation. Zonation, succession and change in ecosystems. Includes broader ecological principles, along with integrated practical and data skills.
Topic 3: Biodiversity and Conservation
Biodiversity at genetic, species, and ecosystem levels. Measurement of biodiversity including diversity indices and interpretation of biodiversity data. Biodiversity and evolution — how evolutionary processes and natural selection give rise to and shape biodiversity. Human impacts on biodiversity including habitat loss, invasive species, pollution, overexploitation, and climate change. Conservation and regeneration — in-situ and ex-situ approaches, protected areas, conservation strategies, evaluation of conservation effectiveness, and relevant international and legal mechanisms. Ethical dimensions of conservation are developed further in the HL Environmental Ethics lens.
Topic 4: Water and Aquatic Food Production Systems
Water systems including the hydrological cycle, groundwater, and surface systems. Water access, use, and security — physical and economic scarcity, infrastructure, governance, sanitation, inequity, and management strategies. Aquatic food production systems — marine and freshwater food production, productivity, harvesting, and sustainability. Water pollution — sources, types of pollutants, impacts on ecosystems and human health, monitoring, and management, including eutrophication, plastic debris, and other contaminants. Includes broader freshwater resource management and the environmental and social dimensions of water use.
Topic 5: Land and Food Production Systems
Soil as a system — composition, structure, inputs, outputs, storages, flows and transformations. Soil properties and their effects on plant growth, biodiversity, nutrient cycling and carbon storage. Agriculture and food systems — terrestrial food production, inputs and outputs of agricultural systems, subsistence and commercial farming, environmental impacts of intensive agriculture and land use change. Food security, food distribution, and global inequalities in the food-security context. Sustainable agriculture and regenerative farming approaches as examples of sustainable practice. Land degradation, soil conservation, and the relationships between land use, food production, and sustainability.
Topic 6: Atmosphere and Climate Change
Composition and structure of the atmosphere. Atmospheric processes and natural regulation. Evidence for human-caused climate change, its causes, observed and projected impacts on ecosystems and societies. Climate mitigation and adaptation strategies and their evaluation. Stratospheric ozone depletion and its management, including the relevant international response. Greenhouse gases and their role in climate regulation, alongside the wider atmospheric processes that shape climate.
Topic 7: Natural Resources
Natural capital and its different values, linked to natural income and ecosystem services, and connected to resource use and sustainability. Renewable and non-renewable resource use and management, including evaluation of environmental costs and benefits. Energy sources and resource-management choices, with evaluation of environmental impacts. Resource extraction and its environmental impacts. Resource depletion and resource management concepts. Solid waste management, including reduction, reuse, and recycling as applications within resource and waste management.
Topic 8: Human Populations and Urban Systems
Human population dynamics and demographic change. Demographic transition, population policies, and factors driving population growth and distribution. Population-resource relationships and pressures associated with human population growth. Urban systems — how cities function as systems, including flows and interactions, and the environmental challenges they generate. Urban air pollution and environmental health consequences of urbanization and industrialization—sustainable urban planning and evaluating urban sustainability using systems thinking, data, and evidence.
HL Lenses
Environmental Law, Economics, and Ethics applied across the course. Environmental law at different scales, including national and international legal approaches, agreements, enforcement, and legal mechanisms, with the Polluter Pays Principle as an application within this lens. Environmental and ecological economics — externalities, market failure, valuation methods, and economic approaches to environmental issues. Environmental ethics — ethical approaches, environmental value, rights and responsibilities, and intergenerational considerations. Designed to support HL students in applying the three lenses to environmental issues and case studies across the course.
How to Use These Flashcards
- Pick a topic — Start with the topic you’re currently studying or the one you feel least confident about.
- Flip each card — Read the front, try to recall the answer, then flip to check.
- Rate yourself — Mark each card Again, Hard, Good, or Easy so you know what to revisit.
- Shuffle — Once you’ve been through a deck, shuffle for mixed practice.
- Revisit weak cards — Come back to the ones you marked Again or Hard.
Tip: Use these alongside the Syllabus Guide to track which topics you’ve mastered.
About These IB ESS Flashcards
These flashcards are organized around the IB Environmental Systems and Societies (ESS) syllabus for 2026. Each deck follows the structure of the official syllabus and the IB ESS Subject Guide.
Decks include key terms and definitions, core concepts, practical skills, and HL-specific content such as the three lenses — Environmental Law, Environmental and Ecological Economics, and Environmental Ethics.
Whether you’re revising for Paper 1, Paper 2, or studying the additional HL content and applying the three HL lenses, these cards build recall and reinforce understanding across all eight topics.