IB Environmental Systems and Societies: ESS Syllabus & Lessons

Foundation

Environmental value systems

• Values and perspectives SL
  6 syllabus points

  • 1.1.1 A perspective is how a particular situation is viewed and understood by an individual. It is based on a mix of personal and collective assumptions, values and beliefs.
  • 1.1.2 Perspectives are informed and justified by sociocultural norms, scientific understandings, laws, religion, economic conditions, local and global events, and lived experience, among other factors.
  • 1.1.3 Values are qualities or principles that people feel have worth and importance in life.
  • 1.1.4 The values that underpin our perspectives can be seen in our communication and actions with the wider community. The values held by organizations can be seen through advertisements, media, policies and actions.
  • 1.1.5 Values surveys can be used to investigate the perspectives shown by a particular social group towards environmental issues.
  • 1.1.6 Worldviews are the lenses shared by groups of people through which they perceive, make sense of and act within their environment. They shape people’s values and perspectives through culture, philosophy, ideology, religion and politics.
• Environmental worldviews SL
  3 syllabus points

  • 1.1.6 Worldviews are the lenses shared by groups of people through which they perceive, make sense of and act within their environment. They shape people’s values and perspectives through culture, philosophy, ideology, religion and politics.
  • 1.1.7 An environmental value system is a model that shows the inputs affecting our perspectives and the outputs resulting from our perspectives.
  • 1.1.8 Environmental perspectives (worldviews) can be classified into the broad categories of technocentric, anthropocentric and ecocentric.
• The environmental movement SL
  2 syllabus points

  • 1.1.9 Perspectives and the beliefs that underpin them change over time in all societies. They can be influenced by government or non-governmental organization (NGO) campaigns or through social and demographic change.
  • 1.1.10 The development of the environmental movement has been influenced by individuals, literature, the media, major environmental disasters, international agreements, new technologies and scientific discoveries.

Systems and models

• Systems SL
  9 syllabus points

  • 1.2.1 Systems are sets of interacting or interdependent components.
  • 1.2.2 A systems approach is a holistic way of visualizing a complex set of interactions, and it can be applied to ecological or societal situations.
  • 1.2.3 In system diagrams, storages are usually represented as rectangular boxes and flows as arrows, with the direction of each arrow indicating the direction of each flow.
  • 1.2.4 Flows are processes that may be either transfers or transformations.
  • 1.2.5 Systems can be open or closed.
  • 1.2.6 The Earth is a single integrated system encompassing the biosphere, the hydrosphere, the cryosphere, the geosphere, the atmosphere and the anthroposphere.
  • 1.2.7 The concept of a system can be applied at a range of scales.
  • 1.2.13 A model is a simplified representation of reality; it can be used to understand how a system works and to predict how it will respond to change.
  • 1.2.14 Simplification of a model involves approximation and, therefore, loss of accuracy.
• Feedback loops SL
  4 syllabus points

  • 1.2.8 Negative feedback loops occur when the output of a process inhibits or reverses the operation of the same process in such a way as to reduce change. They are stabilising as they counteract deviation.
  • 1.2.9 As an open system, an ecosystem will normally exist in a stable equilibrium, either in a steady-state equilibrium or in one developing over time (for example, succession), and will be maintained by stabilising negative feedback loops.
  • 1.2.10 Positive feedback loops occur when a disturbance leads to an amplification of that disturbance, destabilizing the system and driving it away from its equilibrium.
  • 1.2.11 Positive feedback loops will tend to drive the system towards a tipping point.
• System resilience SL
  5 syllabus points

  • 1.2.12 Tipping points can exist within a system where a small alteration in one component can produce large overall changes, resulting in a shift in equilibrium.
  • 1.2.15 Interactions between components in systems can generate emergent properties.
  • 1.2.16 The resilience of a system, ecological or social, refers to its tendency to avoid tipping points and maintain stability.
  • 1.2.17 Diversity and the size of storages within systems can contribute to their resilience and affect their speed of response to change (time lags).
  • 1.2.18 Humans can affect the resilience of systems through reducing these storages and diversity.

Sustainability

• Sustainability SL
  7 syllabus points

  • 1.3.1 Sustainability is a measure of the extent to which practices allow for the long-term viability of a system. It is generally used to refer to the responsible maintenance of socio-ecological systems such that there is no diminishment of conditions for future generations.
  • 1.3.2 Sustainability is comprised of environmental, social and economic pillars.
  • 1.3.3 Environmental sustainability is the use and management of natural resources that allows replacement of the resources, and recovery and regeneration of ecosystems.
  • 1.3.4 Social sustainability focuses on creating the structures and systems, such as health, education, equity, community, that support human well-being.
  • 1.3.5 Economic sustainability focuses on creating the economic structures and systems to support production and consumption of goods and services that will support human needs into the future.
  • 1.3.6 Unit Review Sustainable development meets the needs of the present without compromising the ability of future generations to meet their own needs. Sustainable development applies the concept of sustainability to our social and economic development.
  • 1.3.7 Unsustainable use of natural resources can lead to ecosystem collapse.
• Measuring sustainability SL
  6 syllabus points

  • 1.2.13 A model is a simplified representation of reality; it can be used to understand how a system works and to predict how it will respond to change.
  • 1.3.12 Sustainability indicators include quantitative measures of biodiversity, pollution, human population, climate change, material and carbon footprints, and others. These indicators can be applied on a range of scales, from local to global.
  • 1.3.13 The concept of ecological footprints can be used to measure sustainability. If these footprints are greater than the area or resources available to the population, this indicates unsustainability.
  • 1.3.14 The carbon footprint measures the amount of greenhouse gases (GHGs) produced, measured in carbon dioxide equivalents (in tonnes). The water footprint measures water use (in cubic metres per year).
  • 1.3.15 Biocapacity is the capacity of a given biologically productive area to generate an ongoing supply of renewable resources and to absorb its resulting wastes.
  • 1.3.16 Citizen science plays a role in monitoring Earth systems and whether resources are being used sustainably.
• Development and the SDGs SL
  5 syllabus points

  • 1.3.8 Common indicators of economic development, such as gross domestic product (GDP), neglect the value of natural systems and may lead to unsustainable development.
  • 1.3.9 Environmental justice refers to the right of all people to live in a pollution-free environment, and to have equitable access to natural resources, regardless of issues such as race, gender, socio- economic status, nationality.
  • 1.3.10 Inequalities in income, race, gender and cultural identity within and between different societies lead to disparities in access to water, food and energy.
  • 1.3.11 Sustainability and environmental justice can be applied at the individual to the global operating scale.
  • 1.3.18 The UN Sustainable Development Goals (SDGs) are a set of social and environmental goals and targets to guide action on sustainability and environmental justice.
• Models SL
  4 syllabus points

  • 1.3.17 There are a range of frameworks and models that support our understanding of sustainability, each with uses and limitations.
  • 1.3.19 The planetary boundaries model describes the nine processes and systems that have regulated the stability and resilience of the Earth system in the Holocene epoch. The model also identifies the limits of human disturbance to those systems, and proposes that crossing those limits increases the risk of abrupt and irreversible changes to Earth systems.
  • 1.3.20 The doughnut economics model is a framework for creating a regenerative and distributive economy in order to meet the needs of all people within the means of the planet.
  • 1.3.21 The circular economy is a model that promotes decoupling economic activity from the consumption of finite resources. It has three principles: eliminating waste and pollution, circulating products and materials, and regenerating nature.

Ecology

Species and populations

• Individuals SL
  3 syllabus points

  • 2.1.2 An individual organism is a member of a species.
  • 2.1.3 Classification of organisms allows for efficient identification and prediction of characteristics.
  • 2.1.4 Taxonomists use a variety of tools to identify an organism.
• Populations SL
  5 syllabus points

  • 2.1.1 The biosphere is an ecological system composed of individuals, populations, communities, ecosystems.
  • 2.1.5 A population is a group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.
  • 2.1.6 Factors that determine the distribution of a population can be abiotic or biotic.
  • 2.1.7 Temperature, sunlight, pH, salinity, dissolved oxygen and soil texture are examples of many abiotic factors that affect species distributions in ecosystems.
  • 2.1.9 Populations interact in ecosystems by herbivory, predation, parasitism, mutualism, disease and competition, with ecological, behavioural and evolutionary consequences.
• Population Size SL
  6 syllabus points

  • 2.1.8 A niche describes the particular set of abiotic and biotic conditions and resources upon which an organism or a population depends.
  • 2.1.10 Carrying capacity is the maximum size of a population determined by competition for limited resources.
  • 2.1.11 Population size is regulated by density-dependent factors and negative feedback mechanisms.
  • 2.1.12 Population growth can either be exponential or limited by carrying capacity.
  • 2.1.13 Limiting factors on the growth of human populations have increasingly been eliminated, resulting in consequences for sustainability of ecosystems.
  • 2.1.14 Carrying capacity cannot be easily assessed for human populations.
• Population abundance SL
  3 syllabus points

  • 2.1.15 Population abundance can be estimated using random sampling, systematic sampling or transect sampling.
  • 2.1.16 Random quadrat sampling can be used to estimate population size for non-mobile organisms.
  • 2.1.17 Capture–mark–release–recapture and the Lincoln index can be used to estimate population size for mobile organisms.
• Communities and ecosystems SL
  8 syllabus points

  • 2.1.18 A community is a collection of interacting populations within the ecosystem.
  • 2.1.19 Habitat is the location in which a community, species, population or organism lives.
  • 2.1.20 Ecosystems are open systems in which both energy and matter can enter and exit.
  • 2.1.21 Sustainability is a natural property of ecosystems.
  • 2.1.22 Human activity can lead to tipping points in ecosystem stability.
  • 2.1.23 Keystone species have a role in the sustainability of ecosystems.
  • 2.1.24 The planetary boundaries model indicates that changes to biosphere integrity have passed a critical threshold.
  • 2.1.25 To avoid critical tipping points, loss of biosphere integrity needs to be reversed.
• Knowledge of species’ classifications, niche requirements and life cycles HL
  5 syllabus points

  • 2.1.20 Ecosystems are open systems in which both energy and matter can enter and exit.
  • 2.1.26 There are advantages of using a method of classification that illustrates evolutionary relationships in a clade.
  • 2.1.27 There are difficulties in classifying organisms into the traditional hierarchy of taxa.
  • 2.1.28 The niche of a species can be defined as fundamental or realized.
  • 2.1.30 Knowledge of species’ classifications, niche requirements and life cycles help us to understand the extent of human impacts upon them.
• Understanding the extent of human impacts HL
  1 syllabus point

  • 2.1.30 Knowledge of species’ classifications, niche requirements and life cycles help us to understand the extent of human impacts upon them.

Communities and ecosystems

• Energy SL
  7 syllabus points

  • 2.2.1 Ecosystems are sustained by supplies of energy and matter.
  • 2.2.2 The first law of thermodynamics states that as energy flows through ecosystems, it can be transformed from one form to another but cannot be created or destroyed.
  • 2.2.3 Photosynthesis and cellular respiration transform energy and matter in ecosystems.
  • 2.2.4 Photosynthesis is the conversion of light energy to chemical energy in the form of glucose, some of which can be stored as biomass by autotrophs.
  • 2.2.6 Cellular respiration releases energy from glucose by converting it into a chemical form that can easily be used in carrying out active processes within living cells.
  • 2.2.7 Some of the chemical energy released during cellular respiration is transformed into heat.
  • 2.2.8 The second law of thermodynamics states that energy transformations in ecosystems are inefficient.
• Energy flows SL
  7 syllabus points

  • 2.2.1 Ecosystems are sustained by supplies of energy and matter.
  • 2.2.2 The first law of thermodynamics states that as energy flows through ecosystems, it can be transformed from one form to another but cannot be created or destroyed.
  • 2.2.3 Photosynthesis and cellular respiration transform energy and matter in ecosystems.
  • 2.2.4 Photosynthesis is the conversion of light energy to chemical energy in the form of glucose, some of which can be stored as biomass by autotrophs.
  • 2.2.6 Cellular respiration releases energy from glucose by converting it into a chemical form that can easily be used in carrying out active processes within living cells.
  • 2.2.7 Some of the chemical energy released during cellular respiration is transformed into heat.
  • 2.2.8 The second law of thermodynamics states that energy transformations in ecosystems are inefficient.
• Biomass and food webs SL
  7 syllabus points

  • 2.2.1 Ecosystems are sustained by supplies of energy and matter.
  • 2.2.2 The first law of thermodynamics states that as energy flows through ecosystems, it can be transformed from one form to another but cannot be created or destroyed.
  • 2.2.3 Photosynthesis and cellular respiration transform energy and matter in ecosystems.
  • 2.2.4 Photosynthesis is the conversion of light energy to chemical energy in the form of glucose, some of which can be stored as biomass by autotrophs.
  • 2.2.6 Cellular respiration releases energy from glucose by converting it into a chemical form that can easily be used in carrying out active processes within living cells.
  • 2.2.7 Some of the chemical energy released during cellular respiration is transformed into heat.
  • 2.2.8 The second law of thermodynamics states that energy transformations in ecosystems are inefficient.
• Pollutants, Bioaccumulation and Biomagnification SL
  4 syllabus points

  • 2.2.18 Pollutants that are non-biodegradable, such as polychlorinated biphenyl (PCB), dichlorodiphenyltrichloroethane (DDT) and mercury, cause changes to ecosystems through the processes of bioaccumulation and biomagnification.
  • 2.2.19 Non-biodegradable pollutants are absorbed within microplastics, which increases their transmission in the food chain.
  • 2.2.20 Human activities, such as burning fossil fuels, deforestation, urbanization and agriculture, have impacts on flows of energy and transfers of matter in ecosystems.
  • 2.2.21 Autotrophs synthesize carbon compounds from inorganic sources of carbon and other elements. Heterotrophs obtain carbon compounds from other organisms.
• Productivity, Sustainable Yields and Thermodynamics HL
  7 syllabus points

  • 2.2.23 Primary productivity is the rate of production of biomass using an external energy source and inorganic sources of carbon and other elements.
  • 2.2.24 Secondary productivity is the gain in biomass by consumers using carbon compounds absorbed and assimilated from ingested food.
  • 2.2.25 Net primary productivity is the basis for food chains because it is the quantity of carbon compounds sustainably available to primary consumers.
  • 2.2.26 Maximum sustainable yields (MSYs) are the net primary or net secondary productivity of a system.
  • 2.2.27 Sustainable yields are higher for lower trophic levels.
  • 2.2.28 Ecological efficiency is the percentage of energy received by one trophic level that is passed on to the next level.
  • 2.2.29 The second law of thermodynamics shows how the entropy of a system increases as biomass passes through ecosystems.

Biogeochemical cycles

• A Tour of the Carbon Cycle SL
  11 syllabus points

  • 2.3.1 Biogeochemical cycles ensure chemical elements continue to be available to living organisms.
  • 2.3.2 Biogeochemical cycles have stores, sinks and sources.
  • 2.3.3 Organisms, crude oil and natural gas contain organic stores of carbon. Inorganic stores can be found in the atmosphere, soils and oceans.
  • 2.3.4 Carbon flows between stores in ecosystems by photosynthesis, feeding, defecation, cellular respiration, death and decomposition.
  • 2.3.5 Carbon sequestration is the process of capturing gaseous and atmospheric carbon dioxide and storing it in a solid or liquid form.
  • 2.3.6 Ecosystems can act as stores, sinks or sources of carbon.
  • 2.3.7 Fossil fuels are stores of carbon with unlimited residence times. They were formed when ecosystems acted as carbon sinks in past eras and become carbon sources when burned.
  • 2.3.8 Agricultural systems can act as carbon stores, sources and sinks, depending on the techniques used.
  • 2.3.9 Carbon dioxide is absorbed into the oceans by dissolving and is released as a gas when it comes out of a solution.
  • 2.3.10 Increases in concentrations of dissolved carbon dioxide cause ocean acidification, harming marine animals.
  • 2.3.11 Measures are required to alleviate the effects of human activities on the carbon cycle.
• The Carbon Cycle: Systems, Energy and Change SL
• Carbon in the Lithosphere, Fossil Fuels and Methane HL
  5 syllabus points

  • 2.3.12 The lithosphere contains carbon stores in fossil fuels and in rocks, such as limestone, that contain calcium carbonate.
  • 2.3.13 Reef-building corals and molluscs have hard parts that contain calcium carbonate that can become fossilized in limestone.
  • 2.3.14 In past geological eras, organic matter from partially decomposed plants became fossilized in coal, and partially decomposed marine organisms became fossilized in oil and natural gas held in porous rocks.
  • 2.3.15 Methane is produced from dead organic matter in anaerobic conditions by methanogenic bacteria.
  • 2.3.16 Methane has a residence time of about 10 years in the atmosphere and is eventually oxidized to carbon dioxide.
• The Nitrogen Cycle: From Bacteria to Planetary Boundaries SL
  9 syllabus points

  • 2.3.17 The nitrogen cycle contains organic and inorganic stores.
  • 2.3.18 Bacteria have essential roles in the nitrogen cycle.
  • 2.3.19 Denitrification only happens in anaerobic conditions, such as soils that are waterlogged.
  • 2.3.20 Plants cannot fix nitrogen so atmospheric dinitrogen is unavailable to them unless they form mutualistic associations with nitrogen-fixing bacteria.
  • 2.3.21 Flows in the nitrogen cycle include mineral uptake by producers, consumption, excretion, death, decomposition and ammonification.
  • 2.3.22 Human activities such as deforestation, agriculture, aquaculture and urbanization change the nitrogen cycle.
  • 2.3.23 The Haber process is an industrial process that produces ammonia from nitrogen and hydrogen for use as fertilizer.
  • 2.3.24 Increases in nitrates in the biosphere from human activities have led to the planetary boundary for the nitrogen cycle being crossed, making irreversible changes to Earth systems likely.
  • 2.3.25 Global collaboration is needed to address the uncontrolled use of nitrogen in industrial and agricultural processes and bring the nitrogen cycle back within planetary boundaries.

Biomes

• Climate, Atmospheric Circulation and Biome Distribution SL
  4 syllabus points

  • 2.4.1 Climate describes atmospheric conditions over relatively long periods of time, whereas weather describes the conditions in the atmosphere over a short period of time.
  • 2.4.3 Abiotic factors are the determinants of terrestrial biome distribution.
  • 2.4.5 The tricellular model of atmospheric circulation explains the behaviour of atmospheric systems and the distribution of precipitation and temperature at different latitudes. It also explains how these factors influence the structure and relative productivity of different terrestrial biomes.
  • 2.4.6 The oceans absorb solar radiation and ocean currents distribute the resulting heat around the world.
• Biomes: Characteristics, Distribution and Change HL
  3 syllabus points

  • 2.4.2 A biome is a group of comparable ecosystems that have developed in similar climatic conditions, wherever they occur.
  • 2.4.4 Biomes can be categorized into groups that include freshwater, marine, forest, grassland, desert and tundra. Each of these groups has characteristic abiotic limiting factors, productivity and diversity. They may be further classed into many subcategories (for example, temperate forests, tropical rainforests and boreal forests).
  • 2.4.7 Global warming is leading to changing climates and shifts in biomes.
• Climate Types, ENSO and Tropical Cyclones HL
  6 syllabus points

  • 2.4.8 There are three general patterns of climate types that are connected to biome types.
  • 2.4.9 The biome predicted by any given temperature and rainfall pattern may not develop in an area because of secondary influences or human interventions.
  • 2.4.10 The El Niño Southern Oscillation (ENSO) cycle is the fluctuation in wind and sea surface temperatures that characterizes conditions in the tropical Pacific Ocean. The two opposite and extreme states are El Niño and La Niña, with transitional and neutral states between the extremes.
  • 2.4.11 El Niño is due to a weakening or reversal of the normal east–west (Walker) circulation, which increases surface stratification and decreases upwelling of cold, nutrient-rich water near the coast of north-western South America. La Niña is due to a strengthening of the Walker circulation and reversal of other effects of El Niño.
  • 2.4.12 Tropical cyclones are rapidly circulating storm systems with a low-pressure centre that originate in the tropics and are characterized by strong winds.
  • 2.4.13 Rises in ocean temperatures resulting from global warming are increasing the intensity and frequency of hurricanes and typhoons because warmer water and air have more energy.

Succession

• Zonation and Succession SL
  5 syllabus points

  • 2.2.5 Producers form the first trophic level in a food chain.
  • 2.5.1 Zonation refers to changes in community along an environmental gradient.
  • 2.5.2 Transects can be used to measure biotic and abiotic factors along an environmental gradient in order to determine the variables that affect the distribution of species.
  • 2.5.3 Succession is the replacement of one community by another in an area over time due to changes in biotic and abiotic variables.
  • 2.5.4 Each seral community (sere) in a succession causes changes in environmental conditions that allow the next community to replace it through competition until a stable climax community is reached.
• Secondary Succession, Changes During Succession and Resilience SL
  3 syllabus points

  • 2.5.6 Secondary successions happen on bare soil where there has been a pre-existing community, such as a field where agriculture has ceased or a forest after an intense firestorm.
  • 2.5.7 Energy flow, productivity, species diversity, soil depth and nutrient cycling change over time during succession.
  • 2.5.8 An ecosystem's capacity to tolerate disturbances and maintain equilibrium depends on its diversity and resilience.
• Factors Influencing Succession, Productivity and Plagioclimax HL
  5 syllabus points

  • 2.5.9 The type of community that develops in a succession is influenced by climatic factors, the properties of the local bedrock and soil, geomorphology, together with fire and weather-related events that can occur. There can also be top-down influences from primary consumers or higher trophic levels.
  • 2.5.10 Patterns of net productivity (NP) and gross productivity (GP) change over time in a community undergoing succession.
  • 2.5.11 r- and K-strategist species have reproductive strategies that are better adapted to pioneer and climax communities, respectively.
  • 2.5.12 The concept of a climax community has been challenged, and there is uncertainty over what ecosystems would develop naturally were there no human influences.
  • 2.5.13 Human activity can divert and change the progression of succession leading to a plagioclimax.

Biodiversity and Conservation

Biodiversity

• Biodiversity and Resilience SL
  3 syllabus points

  • 3.1.1 Biodiversity is the total diversity of living systems and it exists at several levels.
  • 3.1.2 The components of diversity contribute to the resilience of ecological systems.
  • 3.1.3 Biodiversity arises from evolutionary processes.
• Natural Selection SL
  3 syllabus points

  • 3.1.4 Natural selection is the mechanism driving evolutionary change.
  • 3.1.5 Evolution by natural selection involves variation, overproduction, competition for limited resources, and differences in adaptation that affect rates of survival and reproduction.
  • 3.1.6 Speciation is the generation of new species through evolution.
• Species diversity SL
  3 syllabus points

  • 3.1.7 Species diversity in communities is a product of richness and evenness.
  • 3.1.8 Simpson's reciprocal index is used to provide a quantitative measure of species diversity, allowing different ecosystems to be compared and for change in a specific ecosystem over time to be monitored.
  • 3.1.9 Knowledge of global and regional biodiversity is needed for the development of effective management strategies to conserve biodiversity.
• Reproductive Isolation and Biodiversity Hotspots HL
  3 syllabus points

  • 3.1.10 Mutation and sexual reproduction increase genetic diversity.
  • 3.1.11 Reproductive isolation can be achieved by geographical separation or, for populations living in the same area, by ecological or behavioural differences.
  • 3.1.12 Biodiversity is spread unevenly across the planet, and certain areas contain a particularly large proportion of species, especially species that are rare and endangered.
• Humans and Selection HL
  2 syllabus points

  • 3.1.13 Human activities have impacted the selective forces acting on species within ecosystems, resulting in evolutionary change in these species.
  • 3.1.14 Artificial selection reduces genetic diversity and, consequently, species resilience.
• Deep Time and the Anthropocene HL
  5 syllabus points

  • 3.1.15 Earth history extends over a period of 4.5 billion years. Processes that occur over an extended timescale have led to the evolution of life on Earth.
  • 3.1.16 Earth history is divided up into geological epochs according to the fossil record.
  • 3.1.17 Mass extinctions are followed by rapid rates of speciation due to increased niche availability.
  • 3.1.18 The Anthropocene is a proposed geological epoch characterized by rapid environmental change and species extinction due to human activity.
  • 3.1.19 Human impacts are having a planetary effect, which will be detectable in the geological record.

Threats to biodiversity

• Human Impact on Biodiversity and Invasive Alien Species SL
  3 syllabus points

  • 3.2.1 Biological diversity is being adversely affected by both direct and indirect influences.
  • 3.2.2 Most ecosystems are subject to multiple human impacts.
  • 3.2.3 Invasive alien species can reduce local biodiversity by competing for limited resources, predation and introduction of diseases or parasites.
• The IUCN Red List and the Tragedy of the Commons SL
  4 syllabus points

  • 3.2.4 The global conservation status of species is assessed by the International Union for Conservation of Nature (IUCN) and is published as the IUCN Red List. Status is based on number of individuals, rate of increase or decrease of the population, breeding potential, geographic range and known threats.
  • 3.2.5 Assigning a global conservation status publicizes the vulnerability of species and allows governments, non-governmental agencies and individual citizens to select appropriate conservation priorities and management strategies.
  • 3.2.6 Investigate three different named species: a species that has become extinct due to human activity; a species that is critically endangered; and a species whose conservation status has been improved by intervention.
  • 3.2.7 The tragedy of the commons describes possible outcomes of the shared unrestricted use of a resource, with implications for sustainability and the impacts on biodiversity.
• Hotspots, KBAs and the Conservation Conflict HL
  3 syllabus points

  • 3.2.8 Biodiversity hotspots are under threat from habitat destruction, which could lead to a significant loss of biological diversity, especially in tropical biomes.
  • 3.2.9 Key areas that should be prioritized for biodiversity conservation have been identified on the basis of the international importance of their species and habitats.
  • 3.2.10 In KBAs, there is conflict between exploitation, sustainable development and conservation.
• Indigenous Land, Justice and Biosphere Integrity HL
  3 syllabus points

  • 3.2.11 Traditional indigenous approaches to land management can be seen as more sustainable but are facing challenges of population growth, economic development, climate change and a lack of governmental support and protection.
  • 3.2.12 Environmental justice must be considered when undertaking conservation efforts to address biodiversity loss.
  • 3.2.13 The planetary boundary \"loss of biosphere integrity\" indicates that species extinctions have already crossed a critical threshold.

Conservation

• Why and How We Conserve SL
  4 syllabus points

  • 3.3.1 Arguments for species and habitat preservation can be based on aesthetic, ecological, economic, ethical and social justifications.
  • 3.3.2 Species-based conservation tends to involve ex situ strategies, and habitat-based conservation tends to involve in situ strategies.
  • 3.3.3 Sometimes a mixed conservation approach is adopted, where both habitat and particular species are considered.
  • 3.3.4 The Convention on Biological Diversity (CBD) is a UN treaty addressing both species-based and habitat-based conservation.
• Habitat Conservation and Reserve Design SL
  2 syllabus points

  • 3.3.5 Habitat conservation strategies protect species by conservation of their natural environment. This may require protection of wild areas or active management.
  • 3.3.6 Effective conservation of biodiversity in nature reserves and national parks depends on an understanding of the biology of target species and on the effect of the size and shape of conservation areas.
• Rewilding, Regeneration and Conservation Choices SL
  3 syllabus points

  • 3.3.7 Natural processes in ecosystems can be regenerated by rewilding.
  • 3.3.8 Conservation and regeneration measures can be used to reverse the decline in biodiversity to ensure a safe operating space for humanity within the biodiversity planetary boundary.
  • 3.3.9 Environmental perspectives and value systems can impact the choice of conservation strategies selected by a society.
• The return of the wolf: judging conservation success HL
  2 syllabus points

  • 3.3.10 Success in conserving and restoring biodiversity by international, governmental and non-governmental organizations depends on their use of media, speed of response, diplomatic constraints, financial resources and political influence.
  • 3.3.13 The success of conservation or regeneration measures needs to be assessed.

4: Water

• Water Systems SL
  6 syllabus points

  • 4.1.1 Movements of water in the hydrosphere are driven by solar radiation and gravity.
  • 4.1.2 The global hydrological cycle operates as a system with stores and flows.
  • 4.1.3 The main stores in the hydrological cycle are the oceans (96.5%), glaciers and ice caps (1.7%), groundwater (1.7%), surface freshwater (0.02%), atmosphere (0.001%), organisms (0.0001%).
  • 4.1.4 Flows in the hydrological cycle include transpiration, sublimation, evaporation, condensation, advection, precipitation, melting, freezing, surface run-off, infiltration, percolation, streamflow and groundwater flow.
  • 4.1.5 Human activities, such as agriculture, deforestation and urbanization, can alter these flows and stores.
  • 4.1.6 The steady state of any water body can be demonstrated through flow diagrams of inputs and outputs.
• Water Security and Scarcity SL
  5 syllabus points

  • 4.2.1 Water security is having access to sufficient amounts of safe drinking water.
  • 4.2.2 Social, cultural, economic and political factors all have an impact on the availability of, and equitable access to, the freshwater required for human well-being.
  • 4.2.3 Human societies undergoing population growth or economic development must increase the supply of water or the efficiency of its utilization.
  • 4.2.4 Water supplies can be increased by constructing dams, reservoirs, rainwater catchment systems, desalination plants and enhancement of natural wetlands.
  • 4.2.5 Water scarcity refers to the limited availability of water to human societies.
• Water Conservation Strategies SL
  3 syllabus points

  • 4.2.6 Water conservation techniques can be applied at a domestic level.
  • 4.2.7 Water conservation strategies can be applied at an industrial level in food production systems.
  • 4.2.8 Mitigation strategies exist to address water scarcity.
• From plankton to plate SL
  3 syllabus points

  • 4.3.1 Phytoplankton and macrophytes provide energy for freshwater and marine food webs.
  • 4.3.2 Humans consume organisms from freshwater and marine environments.
  • 4.3.4 The increasing global demand for seafood has encouraged use of unsustainable harvesting practices and overexploitation.
• Collapse, limits and warming waters SL
  3 syllabus points

  • 4.3.5 Overexploitation has led to the collapse of fisheries.
  • 4.3.6 The maximum sustainable yield (MSY) is the highest possible annual catch that can be sustained over time, so it should be used to set caps on fishing quotas.
  • 4.3.7 Climate change and ocean acidification are having impacts on ecosystems and may cause collapse of some populations in freshwater or marine ecosystems.
• Rules, reserves and fish farms SL
  3 syllabus points

  • 4.3.8 Unsustainable exploitation of freshwater and marine ecosystems can be mitigated through policy legislation addressing the fishing industry and changes in consumer behaviour.
  • 4.3.9 Marine protected areas (MPAs) can be used to support aquatic food chains and maintain sustainable yields.
  • 4.3.10 Aquaculture is the farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants. The industry is expanding to increase food supplies and support economic development, but there are associated environmental impacts.
• Water Pollution and Water Quality SL
  3 syllabus points

  • 4.4.1 Water pollution has multiple sources and has major impacts on marine and freshwater systems.
  • 4.4.2 Plastic debris is accumulating in marine environments. Management is needed to remove plastics from the supply chain and to clear up existing pollution.
  • 4.4.3 Water quality is the measurement of chemical, physical and biological characteristics of water.
• The lake that turned green SL
  4 syllabus points

  • 4.4.5 Eutrophication occurs when lakes, estuaries and coastal waters receive inputs of mineral nutrients, especially nitrates and phosphates, often causing excessive growth of phytoplankton.
  • 4.4.6 Eutrophication leads to a sequence of impacts and changes to the aquatic system.
  • 4.4.7 Eutrophication can substantially impact ecosystem services.
  • 4.4.8 Eutrophication can be addressed at three different levels of management.

HL Lenses

Environmental law

• hl.a.1 Environmental laws #1 HL
• hl.a.1 Environmental laws #2 HL

Environmental economics

• hl.b.1 Environmental economics #1 HL
• hl.b.1 Environmental economics #2 HL

Environmental ethics

• hl.c.1 Introduction to environmental ethics HL
• hl.c.2 Ethical frameworks HL

Skills

• exams.1 Paper 2 Section B SL
• skills.1 Top 10 Command Terms SL