Topic 8: Human systems and resource use
8.1 Human population dynamics
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.
Discuss the use of models in predicting the growth of human populations.
Explain the nature and implications of growth in human populations.
Analyse the impact that national and international development policies can have on human population dynamics and growth.
Discuss the cultural, historical, religious, social, political and economic factors that influence human population dynamics.
8.2 Resource use in society
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.
8.3 Solid domestic waste
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 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.
8.4 Human population carrying capacity
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.
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