IB ESS Syllabus 2022

Comprehensive IB ESS Syllabus

Chapter 1: Fundamentals of ESS

Topic Number Subtopic Key points
1 1.1 Environmental Value Systems
  • A SOCIETY is a group of individuals who share some common characteristics.
  • The ENVIRONMENT of an animal or plant is the external surroundings that act on it and affect its survival.
  • A SYSTEM is something that is made from separate parts that are linked together and affect each other.
  • An environmental value system (EVS) is a particular worldview or set of paradigms that shapes the way an individual, or group of people, perceive and evaluate environmental issues.
  1.2 Systems and Models
  • A system consists of:

Systems diagrams should always be in the same format, with storages (boxes) linked by arrows (flows). They should be kept as visually simple as possible.

Storages-which are places where matter or energy is kept in a system.

Flows- which provide inputs and outputs of energy and matter. The flows are processes that may be either:

Transfers (a change in location)

Transformations (a change in the chemical nature, a change in state or a change in energy)

  1.3 Energy and Equilibria
  • First Law of Thermodynamics (law of conservation of energy) -states that energy cannot be created or destroyed
  • Second Law of Thermodynamics– states that the transfer of energy through a system is inefficient and that energy is transformed into heat.
  1.4 Sustainability
  • Sustainability means using global resources at a rate that allows natural regeneration and minimizes damage to the environment
  • Sustainable development means ‘meeting the needs of the present without compromising the ability of future generations to meet their own needs’.
  •  Indicators of Sustainability: Environmental Impact Assessment, Ecological Footprints, The Millennium Ecosystem Assessment
  1.5 Humans and Pollution
  • Pollution is the addition of a harmful substance to an environment at a rate greater than that at which it can be removed, and which has a noticeable effect on the organisms within the environment.
  •  Dichlorodiphenyltrichloroethane (DDT) is a man-made pesticide that has both advantages and disadvantages.
  • Pollution Management: Changing Human activities, Regulating activities, cleaning up after, Integration of policies.

 

Chapter 2: Ecosystems and Ecology

Topic Number Subtopic Key points
2 2.1 Species and Population
  • Species- A species can be defined as a group of organisms that interbreed and produce fertile offspring.
  • Habitat- Habitat is the kind of biotic and abiotic environment in which a species normally lives.
  • Niche- An ecological niche is best described as where, when, and how an organism lives. An organism’s niche depends not only on where it lives (its habitat) but also on what it does.
  • Abiotic Factors– Are non-living parts of the environment.
  • Biotic Factors- Are the living part of the environment.
  2.2 Communities and Ecosystem
  • A community is many species living together, whereas the term population refers to just one species.
  • An ecosystem is a community of interdependent organisms (the biotic component) and the physical environment (the abiotic component) they inhabit.
  • Photosynthesis converts light energy to chemical energy, which is stored in biomass.
  • A pyramid of numbers represents the number of organisms (producers and consumers) coexisting in an ecosystem.
  • A pyramid of biomass represents the stores of energy and matter at each trophic level measured in units such as grams of biomass per square metre (gm–2).
  • Pyramids of biomass represent the momentary stock, whereas pyramids of productivity show the rate at which that stock is being generated.
  2.3 Flows of Energy and Matter
  • Primary Productivity – the gain by producers (autotrophs) in energy or biomass per unit area per unit time.
  • Gross Primary Productivity (GPP)- is equivalent to the mass of glucose created by photosynthesis per unit area per unit time in primary producers.
  • Net Primary Productivity (NPP)- is the gain by producers in energy or biomass per unit area per unit time remaining after allowing for respiratory losses (R).
  • Secondary Productivity – the biomass gained by heterotrophic organisms, through feeding and absorption, measured in units of mass or energy per unit area per unit time.
  2.4 Biomes, Zonation, and Succession

 

  • Biome distribution depends on levels of insolation (sunlight), temperature and precipitation
  • Zonation refers to changes in communities in space, along an environmental gradient
  • Succession happens when species change the habitat they have colonized and make it more suitable for new species.
  • Climate and edaphic (i.e. relating to soil) factors determine the nature of a climax community. Human factors frequently affect this process through disturbance.
  2.5 Investigating Ecosystems
  • A dichotomous key is a handy tool for identification of organisms that one is not familiar with.
  • Species diversity is considered as a function of two components: the number of different species and the relative numbers of individuals of each species.

Chapter 3: Biodiversity and Conservation

Topic Number Subtopic Key points
3 3.1 Introduction to Biodiversity
  • The word “biodiversity” is derived from the term “biological diversity”. The concept includes habitat, species and genetic diversity
  • Conservation means ‘keeping what we have’.
  • Conservation aims to protect habitats and ecosystems, and species from human-made disturbances, such as deforestation and pollution.
  3.2 Origins of Biodiversity
  • The theory of evolution by natural selection was first developed by Charles Darwin. Because species show variation, those individuals that have adapted best to their surroundings
  • Speciation: With natural selection, the genetic makeup of the species changes over time, and this, combined with isolation can lead to speciation.
  • Isolation is essential to the process of speciation.
  • Mass extinction: A period where at least 75% of total species on Earth were wiped out at the same time.
  3.3 Threats to Biodiversity
  • Rates of Species Loss: 30,000 – 60,000 species a year, 100 – 100,000x greater than background extinction rate
  • Causes of species loss: natural causes, human causes
  • Ecosystem exploitation often prevalent in LICs due to their need to provide income for local economies; HICs can preserve ecosystems as they do not rely on them for income.
  • Red List– Information that assesses the conservation status of species on a worldwide basis.
  • Conservation status– A measure of how endangered a species is; a sliding scale operates from being of least concern to extinct.
  3.4 Conservation of Biodiversity
  • Conservation Organizations can be international, governmental or non-governmental, with varying levels of success when approaching conservation due to their use of media, their speed of response, diplomatic constraints, finances and influence
  • For many years, international zoos have focused on keeping endangered or critically endangered animals so that they can protect them from the dangers they face in the wild.
  • Captive breeding programmes maintain population numbers and genetic diversity, with a view to returning animals to the wild once their natural habitats have been protected.

 

Chapter 4: Water, Aquatic, Food Production Systems and Societies

Topic Number Subtopic Key points
4 4.1 ​​Introduction to Water Systems

 

  • The hydrological cycle refers to the cycle of water between the biosphere, atmosphere, lithosphere, and hydrosphere.
  • System – any set of interrelated components which are connected to form a working unit.
  • Evapotranspiration – the combined losses of evaporation and transpiration.
  4.2 Access to Freshwater

 

  • The availability of fresh water is likely to become more stressed in the future. This may be the result of climate change
  • Redistribution is an example of a technocratic environmental value system.
  • Advantages of dams– include flood and drought control, irrigation, hydroelectric power, improved navigation, recreation and tourism.
  4.3 Aquatic Food Production Systems

 

  • Sustainable Yield is the amount of increase per unit time (i.e. the rate of increase).
  • Aquaculture has increased rapidly since the 1990s. Aquaculture involves raising fish commercially, usually for food
  • Managing Fisheries: Total allowable catches, Fishing license, Boat capacity management, Reducing environmental impact, Specifying a minimum mesh size on nets.
  4.4 Water Pollution

 

  • Water pollution: Freshwater and marine pollution sources include run-off, sewage, industrial discharge, solid domestic waste, transport, recreation and tourism, and energy waste.
  • The Trent Biotic Index is based on the disappearance of indicator species as the level of organic pollution increases in a river.
  • Eutrophication refers to the nutrient enrichment of streams, ponds, and groundwater.
  • Red tide is a common name for algal blooms, which are large concentrations of aquatic microorganisms.

 

Chapter 5: Soil Systems, Terrestrial Food, Production Systems and Societies

Topic Number Subtopic Key points
5 5.1 Introduction to Soil systems
  • A soil profile is a vertical section through a soil, and is divided into horizons (distinguishable layers).
  • Soil-forming processes involve: Gains and losses of material to and from the profile, Movement of water between the horizons, Chemical Transformations Within Each Horizon.
  • Triangular graphs are used to show data that can be divided into three parts, such as the proportion of sand, silt and clay in a soil.
5.2 Terrestial Food Production Systems
  • The sustainability of terrestrial food production systems is influenced by several factors, including the degree of dependence on agriculture and the value of agricultural output.
  • Food production and distribution are very uneven throughout the world. Food production systems vary in terms of sustainability, use of water, fertilizers, pesticides and machinery.
  • Socio-cultural factors influence tastes and the development of different food production systems
5.3 Soil Degradation and Conservation

  

 

  • Soil degradation and erosion are the decline in the amount and quality of a soil. Soil degradation leads to a reduction in soil fertility.
  • Soil Conservation Methods: Revegetation, Measures to stop bank erosion, Measures to stop gully enlargement, Crop management, Slope run-off control, Prevention of erosion from point sources such as roads, feedlots, Suppression of wind erosion.

 

Chapter 6: Atmospheric Systems and Societies

Topic Number Subtopic Key points
6 6.1 Introduction to Atmosphere

 

  • The Earth’s atmosphere is both influenced by the biosphere and influences the biosphere.
  • Insolation refers to incoming solar radiation.
  • The gasses create a ‘thermal blanket’ that maintains an average Earth temperature that can support life.
  • These gasses act in the same way that glass acts in a greenhouse, they are called greenhouse gasses.
  • Troposphere – the lowest layer of the atmosphere extending from the ground’s surface to the tropopause (between 10 km and 15 km).
  • Stratosphere – a layer of the Earth’s atmosphere extending from the tropopause to about 50 km.
  • Albedo – the amount of incoming radiation that is reflected by the Earth’s surface and atmosphere.
  6.2 Stratospheric Ozone

 

  • Increased ultraviolet radiation is damaging to ecosystems as it damages plant tissues and plankton.
  • UV radiation can also cause genetic mutations in DNA. There are also negative impacts on reproduction.
  • The 1987 Montreal Protocol on Substances that Deplete the Ozone Layer is the most significant and successful international agreement relating to an environmental issue.
  6.3 Photochemical Smog

 

  • Smog is formed as the result of pollution by volatile organic compounds (VOCs), carbon monoxide, carbon dioxide, black carbon or soot, unburned hydrocarbon, oxides of nitrogen (NOx), and oxides of sulfur
  • Primary pollutant- The main cause of photochemical smog (ground level/tropospheric ozone) is the volume of road transport concentrated in cities.
  • Secondary pollutant– Tropospheric ozone—or ground-level ozone it is formed by reactions involving oxides of nitrogen (NOx).
  • Tropospheric ozone – “bad” ozone which is found at ground level i.e. within the troposphere, and is formed when oxygen molecules react with molecules from nitrogen dioxide in the presence of sunlight.
  6.4 Acid Deposition

 

  • Acid deposition is the increased acidity of rainfall and dry deposition.
  • Pollution Management strategies: The first main type of strategy is to alter human activity and to reduce the production of pollutants. The most effective long-term treatment is to reduce the emissions of SOx and NOx.

 

Chapter 7: Climate Change and Energy Production

Topic Number Subtopic Key points
7 7.1 Energy Choices & Security

 

  • Energy can be generated from both Renewable and Non Renewable sources.
  • Energy Security is a country’s ability to secure all its energy needs whereas energy insecurity refers to a lack of security over energy sources.
  • Sustainability: The use of resources at such a rate that allows natural regeneration and/ or minimizes damage to the environment.
  7.2  Climate Change, Causes and Impact

 

  • Ocean Circulatory systems: Warm ocean currents move water away from the equator, whereas cold ocean currents move water away from cold regions towards the equator.
  • Specific Heat Capacity– Specific heat capacity is the amount of energy it takes to raise the temperature of 1 g of substance by 1 °C.
  • Air Motion- The basic cause of air motion is the unequal heating of Earth’s surface.
  • Climate sensitivity is a measure of how much the Earth’s climate will cool or warm after a change in the climate system, for instance, how much it will warm for doubling in carbon dioxide concentrations.
  7.3 Climate change- Mitigation and Adaptation

 

  • Mitigation involves reduction and/or stabilization of greenhouse gas (GHG) emissions and their removal from the atmosphere.
  • Decarbonization– It refers to a large reduction of carbon dioxide per value of gross world product
  • Adaptation refers to efforts to live with the consequences of climate change

 

Chapter 8: Human Systems and Resource Use

Topic Number Subtopic Key points
8 8.1 Human Population and Dynamics

 

  • Crude Birth Rate– is defined as the number of live births per thousand people in a population.
  • Population Mortality- is defined as the number of live births per thousand people in a population.
  • Total Fertility Rate- The total fertility rate is the average number of births per woman of childbearing age.
  • Natural increase rate (NIR)- is the increase in population as a result of the birth rate exceeding the death rate.
  • Doubling time (DT)– refers to the length of time it takes for a population to double in size
  • Factors influencing the birth rate- cultural, historical, religious, social, political, and economic factors.
  • Factors influencing the death rate- include the age-structure of the population, availability of clean water, sanitation, adequate housing, etc
  • The most famous anti-natalist policy is China’s one-child policy.
  8.2 Resource Use in Society

 

  • Natural Capital is the total quantity of natural resources.
  • Sustainability is living within the means of nature (i.e. on the ‘interest’ or sustainable income generated by natural capital) and ensuring resources are not degraded (i.e. natural capital is not depleted and/or polluted) so that future generations can continue to use the resource.
  8.3 Solid Domestic Waste

 

  • Solid domestic waste – household waste/garbage—it does not include faecal waste.
  • Landfill – the disposal of waste onto or into the land.
  • Incineration – the burning of waste.
  • Composting – the breakdown/ natural decay of organic material and its use as a fertilizer in soil
  8.4 Carrying Capacity & Ecological Footprints

 

  • Carrying capacity is the maximum number of a species or “load” that can be sustainably supported by a given environment.
  • Optimum population is the number of people who, when using all the available resources, will produce the highest per capita economic return. It is the point at which the population has the highest standard of living and quality of life.
  • Over-population occurs when there are too many people relative to the resources and technology locally available to attain the optimum standard of living. They suffer from natural disasters such as drought and famine and are characterized by low incomes, poverty, poor living conditions, and a high level of emigration.
  • Under-population occurs when there are far more resources in an area (e.g. food production, energy and minerals) than can be used by the people living there in order to reach the optimum population.
  • The ecological footprint of a population is the area of land that would be required to provide all of the population’s resources and assimilate all of its wastes.

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