Embedded Files
Lots of useful pollution videos here.
Significant ideas:
A variety of models and indicators are employed to quantify human population dynamics.
Human population growth rates are impacted by a complex range of changing factors.
Knowledge and understanding:
Demographic tools for quantifying human population include crude birth rate (CBR), crude death rate (CDR), total fertility rate (TFR), doubling time (DT) and natural increase rate (NIR).
Global human population has followed a rapid growth curve, but there is uncertainty as to how this may be changing.
As the human population grows, increased stress is placed on all of the Earth’s systems.
Age–gender pyramids and demographic transition models (DTM) can be useful in the prediction of human population growth. The DTM is a model that shows how a population transitions from a pre-industrial stage with high CBRs and CDRs to an economically advanced stage with low or declining CBRs and low CDRs.
Influences on human population dynamics include cultural, historical, religious, social, political and economic factors.
National and international development policies may also have an impact on human population dynamics.
Applications and skills:
Calculate values of CBR, CDR, TFR, DT and NIR.
Explain the relative values of CBR, CDR, TFR, DT and NIR.
Analyse age–gender pyramids and diagrams showing demographic transition models.
Significant ideas:
The renewability of natural capital has implications for its sustainable use.
The status and economic value of natural capital is dynamic.
Knowledge and understanding:
Renewable natural capital can be generated and/or replaced as fast as it is being used. It includes living species and ecosystems that use solar energy and photosynthesis, as well as non-living items, such as groundwater and the ozone layer.
Non-renewable natural capital is either irreplaceable or can only be replaced over geological timescales; for example, fossil fuels, soil and minerals.
Renewable natural capital can be utilized sustainably or unsustainably. If renewable natural capital is used beyond its natural income this use becomes unsustainable.
The impacts of extraction, transport and processing of a renewable natural capital may cause damage, making this natural capital unsustainable.
Natural capital provides goods (such as tangible products) and services (such as climate regulation) that have value. This value may be aesthetic, cultural, economic, environmental, ethical, intrinsic, social, spiritual or technological.
The concept of a natural capital is dynamic. Whether or not something has the status of natural capital, and the marketable value of that capital varies regionally and over time and is influenced by cultural, social, economic, environmental, technological and political factors. Examples include cork, uranium and lithium.
Applications and skills:
Outline an example of how renewable and non-renewable natural capital has been mismanaged.
Explain the dynamic nature of the concept of natural capital.
Guidance:
The valuation of natural capital can be divided into the following two main categories.
– Use of valuation: resources that have a price—marketable goods, ecological functions, recreational function
– Non-use of valuation: resources that have intrinsic value (the right to exist), future uses (medicines, potential gene pool), existence value (Amazon rainforest), present for future generations
Consider at least two examples of how the status of natural capital can vary.
“Natural capital” is often used interchangeably with the term “resource”, and the rate of its replacement is referred to as “natural income”.
International-mindedness:
There are marked cultural differences in attitudes to the management of natural capital.
Theory of knowledge:
As resources become scarce, we have to make decisions about how to use them—to what extent should potential damage to the environment limit our pursuit of knowledge?
Connections:
ESS: Environmental values systems (1.1); sustainability (1.4)
Diploma Programme: Social and cultural anthropology; design technology (topics 2 and 8); physics (topic 8); geography (topic 4); economics
The concept of a natural capital is dynamic- cork, uranium and lithium
The concept of a natural capital is dynamic- cork, uranium and lithium
Newspaper articles on how renewable and non-renewable natural capital has been mismanaged
Newspaper articles on how renewable and non-renewable natural capital has been mismanaged
Significant ideas:
Pollution is a highly diverse phenomenon of human disturbance in ecosystems.
Pollution management strategies can be applied at different levels.
Knowledge and understanding:
Pollution is the addition of a substance or an agent to an environment through human activity, at a rate greater than that at which it can be rendered harmless by the environment, and which has an appreciable effect on the organisms in the environment.
Pollutants may be in the form of organic or inorganic substances, light, sound or thermal energy, biological agents or invasive species, and may derive from a wide range of human activities including the combustion of fossil fuels.
Pollution may be non-point or point source, persistent or biodegradable, acute or chronic.
Pollutants may be primary (active on emission) or secondary (arising from primary pollutants undergoing physical or chemical change).
Dichlorodiphenyltrichloroethane (DDT) exemplifies a conflict between the utility of a “pollutant” and its effect on the environment.
Applications and skills:
Construct systems diagrams to show the impact of pollutants.
Evaluate the effectiveness of each of the three different levels of intervention, with reference to figure 3.
Evaluate the uses of DDT
Guidance:
The terms “pollutant” and “contaminant” in environmental chemistry are considered more or less synonymous.
Pollution which arises from numerous widely dispersed origins is described as non-point source. Point source pollution arises from a single clearly identifiable site.
“Biodegradable” means capable of being broken down by natural biological processes
The principles of this sub-topic, particularly figure 3, should be used throughout the course when addressing issues of pollution.
Students should be aware that for some pollutants there may be a time lag before an appreciable effect on organisms is evident.
With reference to figure 3, students should appreciate the advantages of employing the earlier strategies of pollution management over the later ones, and the importance of collaboration.
Students might demonstrate knowledge of both the anti-malarial and agricultural use of DDT.
International-mindedness:
Pollution cannot be contained by national boundaries and therefore can act either locally, regionally or globally.
Theory of knowledge:
Experts sometimes disagree about pollution management strategies—on what basis might we decide between the judgments of the experts if they disagree?
Connections:
ESS: Stratospheric ozone (6.2); photochemical smog (6.3); water pollution (4.4); terrestrial food production systems and food choices (5.2); human population carrying capacity (8.4); biodiversity and conservation (topic 3)
Diploma Programme: Social and cultural anthropology; chemistry (options A, B, C and D); design technology (topic 2), geography (option G); economics
Significant ideas:
Solid domestic waste (SDW) is increasing as a result of growing human populations and consumption.
Both the production and management of SDW can have significant influence on sustainability.
Knowledge and understanding:
There are different types of SDW, the volume and composition of which changes over time.
The abundance and prevalence of non-biodegradable pollution (such as plastic, batteries or e-waste) in particular has become a major environmental issue.
Waste disposal options include landfills, incineration, recycling and composting.
There are a variety of strategies that can be used to manage SDW (refer to figure 3) influenced by cultural, economic, technological and political barriers.
These strategies include:
– altering human activity—for example, through a reduction of consumption and composting of food waste.
– controlling the release of pollutant—governments create legislation to encourage recycling and reuse initiatives and impose taxes for SDW collection and on disposable items
– reclaiming landfills, using SDW for waste-to-energy programmes, implementing initiatives to remove plastics from the Great Pacific garbage patch (clean-up and restoration).
Applications and skills:
Evaluate SDW disposal options.
Compare and contrast pollution management strategies for SDW.
Evaluate, with reference to figure 3, pollution management strategies for SDW by considering recycling, incineration, composting and landfills.
Guidance:
SDW includes household waste such as paper, glass, metal, plastics, organic (kitchen or garden), packaging, construction debris, and clothing.
Students should consider the amount and source of non-biodegradable pollution generated within a chosen locality and how it is managed.
The adoption of the circular economy provides an alternative approach to waste and sustainability.
International-mindedness:
Pollution can be transborder; the pollution from one country may affect another.
Differences in development level of countries can influence the amount and type of SDW they generate.
Theory of knowledge:
The circular economy can be seen as a paradigm shift—does knowledge develop through paradigm shifts in all areas of knowledge?
Connections:
ESS: Sustainability (1.4); humans and pollution (1.5); flows of energy and matter (2.3); water pollution (4.4); soil degradation and conservation (5.3); acid deposition (6.4)
Diploma Programme: Chemistry (option A); geography (topic 4 and option B)
Significant ideas:
Human carrying capacity is difficult to quantify.
The EF is a model that makes it possible to determine whether human populations are living within carrying capacity.
Knowledge and understanding:
Carrying capacity is the maximum number of a species, or “load”, that can be sustainably supported by a given area.
It is possible to estimate the carrying capacity of an environment for a given species; however, this is problematic in the case of human populations for a number of reasons.
An EF is the area of land and water required to support a defined human population at a given standard of living. The measure of an EF takes into account the area required to provide all the resources needed by the population, and the assimilation of all wastes.
EF is a model used to estimate the demands that human populations place on the environment.
EFs may vary significantly by country and by individual and include aspects such as lifestyle choices (EVS), productivity of food production systems, land use and industry. If the EF of a human population is greater than the land area available to it, this indicates that the population is unsustainable and exceeds the carrying capacity of that area.
Degradation of the environment, together with the consumption of finite resources, is expected to limit human population growth.
• If human populations do not live sustainably, they will exceed carrying capacity and risk collapse.
Applications and skills:
Evaluate the application of carrying capacity to local and global human populations.
Compare and contrast the differences in the EF of two countries.
Evaluate how EVSs impact the EFs of individuals or populations.
Guidance:
Discussion of the application of the carrying capacity that allows human populations to grow beyond the boundaries set by their local resources should include:
– the range of resources used
– human ingenuity, meaning that humans are able to substitute one material for another
– variations in lifestyles
– importation of resources
– technological developments that give rise to continual changes in the resources required and that are available for consumption.
Because carrying capacity for human populations is difficult to calculate, it is also difficult to estimate the extent to which they are approaching or exceeding carrying capacity, although environmental indicators (see sub-topic 1.4) may help in this respect.
The EF is a model that provides a way round this dilemma. Instead of focusing on a given environment and trying to calculate the carrying capacity it provides, it focuses on a given population (with its current rate of resource consumption) and estimates the area of environment necessary to sustainably support that particular population. The size of this area is compared with the area available to the population, then gives an indication of whether the population is living sustainably and within the carrying capacity provided.
International-mindedness:
Sustainability is the responsible use and management of global resources that allows natural regeneration and minimizes environmental damage.
Theory of knowledge:
Human carrying capacity is difficult to quantify and contains elements of subjective judgment. It has been claimed that historians cannot be unbiased—could the same be said of environmental scientists when making knowledge claims?
Connections:
ESS: Sustainability (1.4); humans and pollution (1.5); access to fresh water (4.2); aquatic food production systems (4.3); terrestrial food production systems and food choices (5.2); energy choices and security (7.1); resource use in society (8.2)
Diploma Programme: Geography (topic 4 and option G)
Google Sites
Report abuse