Population and Resources

Under population

Under population

too few people to use resources efficiently for a given level of technology e.g. Canada. Increasing population would lead to more effective use of resources and increased living standards for all.

Optimum Population

The ideal balance between population and resources. A population size in an area which, working with all resources, gives the highest standards of living by maximising capital.

Over population

Too many people in the area relative to the available resources putting pressure on resources therefore living standards fall e.g. Bangladesh.

How can optimum population be limited? How can this increased?

Population growth is limited by environmental factors that limit resource availability. The optimum population can increase with use of technology increasing crop yield. Optimum population can also change depending on population structure- a low dependency ratio would mean a higher population can be supported.

Outline cost and benefits of overpopulation.

Cheap labour however lots of negatives such as low income/capital, unemployment, outward migration, insufficient resources.

Outline cost and benefits of underpopulation.

Lots of space, lower house prices however not enough workers (therefore no multiplier effect). Living standards and incomes are high but not maximised.

Ecological footprint

total productive biocapacity/total population. The bigger the ecological footprint, the more demanding ecological footprint than entitled to. Countries with highest ecological footprint = Qatar (11.7gha/person).

Measures the environmental impact of human activities and calculates the amount of productive land required to produce the resources used at any scale.

Carrying Capacity and IPAT

Refer to the maximum population a given environment is capable of supporting in the long-term, within the limits of the natural resources. Calculated using IPAT (total impact = population x affluence x technology).

Where levels of affluence and technology are higher, more resources are used therefore fewer people can be supported. However technology can also reduce resources use impact. More affluent countries have a higher CC as they import goods and export waste products, utilising the resources of LICs.

Has CC been exceeded?

Many argue that CC has been exceeded in some areas e.g. Sahel, where famines are regular. On a global scale population growth is starting to slow and adjust to CC (Sigmoidal curve).

What negative implications have been a result of ecological footprint

Climate change.

More land used for settlement, industry → loss of habitats and deforestation.

Degradation of natural ecosystems (e.g. 10% of coral reefs degraded beyond recovery).

Increased threat of species extinction and overfishing.

Over cultivation and over grazing worsens soil quality.

Sigmoidal curve (stages)

1. Lag phase

2. Exponential growth phase- where BR>DR and mortality is low as there are an abundance of resources and minimal environmental resistance that limits population growth.

3. Transitional phase- as population continues to grow, resources become limited and overshoots carrying capacity therefore BR fall and DR increase due to famine, disease, conflict.

4. Plateau phase- eventually increasing mortality = natality rate. Population reaches CC and fluctuates above and below CC.

What is the PRP Model?

Population, Resources and Pollution. Shows the ecological relationships that exist between population growth, human demand and environmental consequences. Contain a number of +ve and -ve feedbacks. Takes a systems approach into sustainable solutions.

Negative Feedbacks

Control biological systems e.g. continued soil erosion from overgrazing → reduction in food production and decline in living standard an reduced yields therefore causing populations to decline. PRP model suggests negative feedback will be the consequence of continued population growth as it nears to CC → population decline and back to equilibrium.

Positive Feedbacks

Enhances/amplifies change e.g. agricultural and population can be seen as a positive feedback spiral. Population growth → higher food demand driving an increase in food production and allows for population to further grow through increased yields and use of technology therefore further food demand. To cause problems of depletion and env degradation long-term.

UN alternative scenarios

gives estimated medium, high and low future prediction for population growth until 2050, based on 2010 rates. Ranges between 9.6bn-12.3bn by 2100.

Malthusian- theory, evidence, limitations

Predicted a gloomy view of the human race (1798). States population would grow until it reached limit food supply. Food supply grows arithmetically whereas population growth geometrically. Exponential growth prevented by checks. Can be positive (increased mortality e.g. war, famine) or negative (people reducing fertility).

Limitations: too simplistic, ignores reality that only poor go hungry, claims that poverty results from poor distribution not physical limits to production and doesn’t take into account technological revolutions.

neo-Malthusian

1972- the limits to growth model by Club of Rome. If the present growth trends in world production, industrialisation, pollution continues unchanged the limits to growth will be reached sometime by 2040/2050. The most probable result will be a sudden, uncontrollable declines in population. Famines, wars, strategies will become more common. Evidence to support neo-Malthusian: the regular famines that occurred in Sudan, Ethiopian etc. The wars that we often fought over food, water and energy resources. Water scarcities and increasing pandemics.

Boserup

1965: challenged the idea that there were limits to human population growth, saying that people would always produce sufficient food to meet their needs. Environment has limits that restrict activity that can be altered by use of appropriate technology e.g. farms becoming intensive as pressures on food resources grow.

Evidence: green revolution, HYVs increasing yields, increasing intensity of farming, population and living standards are increasing despite crisis of desertification and deforestation.

Limitations: limits to which humans can reduce limits is becoming stretched.

Simon (theory, evidence, criticisms)

Optimistic view. Wrote ‘the ultimate resources’ in which he argues that human brain power means the supply of natural resource can be infinite. Argued that every important long-term measure of human material welfare shows improvement in all areas of the world therefore shows humans are better off.

Evidence: raw materials less scarce, water cleanliness increase, food production increased.

Criticisms: conditions in some countries have gotten worse due to climate change.