Published on

A2 Through revision of population theories and models

Published in: Technology, Economy & Finance
1 Comment
No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  1. 1. Population A2 Revision
  2. 2. The Challenge <ul><li>The world population is growing…fast </li></ul><ul><li>Since 1960 the population of the earth has doubled </li></ul><ul><li>This has been caused by </li></ul><ul><li>Better medicine and treatment of disease </li></ul><ul><li>Better access to healthcare </li></ul><ul><li>Better sanitation and hygiene </li></ul><ul><li>Better diet and food supply </li></ul>
  3. 3. <ul><li>90% of all babies born each day are born in LEDC’s </li></ul><ul><li>Of the 4.8bn living there: </li></ul><ul><li>60% lack basic sanitation </li></ul><ul><li>30% are without clean water </li></ul><ul><li>25% have inadequate housing </li></ul><ul><li>20% have no access to healthcare </li></ul>
  4. 4. <ul><li>By 2050 the population of the world is expected to reach 9bn </li></ul><ul><li>It’s unlikely to level out before 2200 </li></ul><ul><li>All have this has lead to many issues and worries for the future: </li></ul><ul><li>Disparity </li></ul><ul><li>Consumption </li></ul><ul><li>Production </li></ul><ul><li>Migration </li></ul><ul><li>Family size </li></ul>
  5. 5. Systems <ul><li>Population change is the result of two processes </li></ul><ul><li>Natural change and migrational change </li></ul><ul><li>Its an OPEN SYSTEM </li></ul><ul><li>Inputs = births and inward migration </li></ul><ul><li>Outputs = Deaths and outward migration </li></ul><ul><li>When births exceed deaths its called natural increase </li></ul><ul><li>Net migration gain/ net migration loss </li></ul>
  6. 6. Measures <ul><li>Fertility </li></ul><ul><li>Measured per 1000 people living in an area – Crude Birth rate (This is a weak measurement) </li></ul><ul><li>General Fertility rate – Number of Births per year per 100 women of fertile age. </li></ul>
  7. 7. Measures <ul><li>Mortality </li></ul><ul><li>Measured per 1000 people living in an area – Crude death rate (This is a weak measurement) </li></ul><ul><li>Infant Mortality rate: Number of child deaths under the age of 1 per 1000 live births in a given year. </li></ul>
  8. 8. The demographic status of the world's population
  9. 10. Measuring Population Change
  10. 11. <ul><li>Most change is measured by a census but these can sometimes be unreliable especially in LEDC’s </li></ul><ul><li>As management, money, education and rurality can all play an issue </li></ul><ul><li>3 categories are important to find information on: </li></ul><ul><li>Population Distribution </li></ul><ul><li>Population Structure </li></ul><ul><li>Population Change </li></ul>
  11. 12. <ul><li>To do this the UNO recommends that questions on the following should be asked: </li></ul><ul><li>Total Population and distribution within the country </li></ul><ul><li>Sex age and marital status </li></ul><ul><li>P.O.B and nationality </li></ul><ul><li>Mother tongue and literacy </li></ul><ul><li>Occupation </li></ul><ul><li>Residential location, urban or rural </li></ul><ul><li>Household type (Size, structure) </li></ul><ul><li>Fertility </li></ul>
  12. 13. <ul><li>In MEDC’s most census are carried out every ten years </li></ul><ul><li>Population Distribution is generally shown as a Cartographic chart or topological map </li></ul>
  13. 14. Density <ul><li>Measure as a Choropleth map </li></ul>
  14. 15. Limitations of Choropleth map <ul><li>Only represent an average value for each area not matter what the scale </li></ul><ul><li>Mean values are generalisations </li></ul><ul><li>When they differ the neighbouring state gives an impression of a sudden break whereas reality says its gradual </li></ul><ul><li>Does not take into account terrain </li></ul><ul><li>Who decides the amount of classes </li></ul><ul><li>How are they delineated </li></ul>
  15. 16. Measuring change <ul><li>Can be done by Choropleth map </li></ul><ul><li>Graphs </li></ul>
  16. 17. Natural Change <ul><li>Changes in fertility </li></ul><ul><li>Mortality </li></ul><ul><li>Birth control </li></ul>
  17. 18. Development Improving living standards Personal aspirations Materialism Awareness Social traits Awareness of need for BC Women's rights Perception of children Sensitivity to cost Government Balance pop’n and resources Access to BC Healthcare Education Environment High Infant Mortality No access to BC or health care Large extended families Cheap child labour Cultural Heritage Religion Children as symbols of male virility Ignorance Focus/ education Birth Control Weakening factors Strengthening factors
  18. 19. Spread Of Disease <ul><li>Diseases such as AIDS can have an immediate effect on population </li></ul>
  19. 20. Demographic Transition model
  20. 21. The Cairo Conference <ul><li>Sept 1994 – 180 govt’s and hundreds of NGO’s </li></ul><ul><li>Ended with a 20 yr plan </li></ul><ul><li>Goals: </li></ul><ul><li>Increase investment in women's reproductive health </li></ul><ul><li>Reducing number of unsafe abortions </li></ul><ul><li>Eliminate female genital mutilation </li></ul><ul><li>Enforce marriage age laws </li></ul><ul><li>Improve sex education </li></ul><ul><li>Increase opportunities for women </li></ul>
  21. 22. Population theories Malthus, Boserup and the Club of Rome
  22. 23. Thomas Malthus <ul><li>1766-1834. Born near Guildford! </li></ul><ul><li>Wrote ‘An essay in the First Principle of population’ first published in 1798 </li></ul><ul><li>Debatable whether the principles of Malthus two hundred years ago ( that were very revolutionary and controversial ) have any relevance to the modern world. </li></ul><ul><li>The world population in 1798 was at nine million people. We have now passed the six billion mark. </li></ul>
  23. 24. The Core Principles of Malthus: <ul><li>Food is necessary for human existence </li></ul><ul><li>Human population tends to grow faster than the power in the earth to produce subsistence </li></ul><ul><li>The effects of these two unequal powers must be kept equal </li></ul><ul><li>Since humans tend not to limit their population size voluntarily - “preventive checks” in Malthus’ terminology. </li></ul>
  24. 25. <ul><li>Malthus recognised that population if unchecked, grows at a geometric rate: </li></ul><ul><li>1 2 4 8 16 32 </li></ul><ul><li>However, food only increases at an arithmetic rate, as land is finite. </li></ul><ul><li>1 2 3 4 5 6 </li></ul>
  25. 26. and therefore he said…. War, famine, disease.
  26. 27. CHECKS <ul><li>Malthus suggested that once this ceiling (catastrophe) had been reached, further growth in population would be prevented by negative and positive checks. He saw the checks as a natural method of population control. They can be split up into 3 groups…. </li></ul>
  27. 28. Negative checks (decreased birth rate)…. <ul><li>Negative Checks were used to limit the population growth. It included abstinence/ postponement of marriage which lowered the fertility rate. </li></ul><ul><li>Malthus favoured moral restraint (including late marriage and sexual abstinence) as a check on population growth. However, it is worth noting that Malthus proposed this only for the working and poor classes! </li></ul>
  28. 29. Positive checks (increased death rate) <ul><li>Positive Checks were ways to reduce population size by events such as famine, disease, war - increasing the mortality rate and reducing life expectancy. </li></ul>
  29. 30. 'J' Curve - Population Crash Model
  30. 31. Was Malthus right? <ul><li>There has been a population explosion </li></ul><ul><li>Africa – repeated famines, wars, food crisis, environmental degradation, soil erosion, crop failure and disastrous floods – so was he right? </li></ul>
  31. 32. But….. <ul><li>Technological improvements which he could not have foreseen </li></ul><ul><li>The increased amount of cropland due to irrigation </li></ul><ul><li>Reduced population growth as countries move through the DTM </li></ul>
  32. 33. The Club of Rome <ul><li>Group of industrialists, scientists, economists and statesmen from 10 countries </li></ul><ul><li>Published ‘The Limits to Growth’ in 1972 </li></ul>
  33. 34. The Club of Rome – basic conclusion…. <ul><li>If present growth trends in world population continue and if associated industrialisation, pollution, food production and resource depletion continue unchanged, the limits to growth on this planet will be reached sometime in the next 100 years. </li></ul><ul><li>The most probably result will be sudden and uncontrollable decline in both population and industrial capacity </li></ul>
  34. 36. Is the Club of Rome right? <ul><li>Don’t panic yet! </li></ul><ul><li>Doesn’t take human dimension sufficiently into account </li></ul><ul><li>Human race is adaptable and innovative </li></ul><ul><li>Human responses have changed – e.g. alternative sources of fuel (to replace fossil fuels), HYVs seeds to prevent starvation in parts of Asia </li></ul>
  35. 37. Esther Boserup 1965 <ul><li>Boserup believed tat people have the resources of knowledge and technology to increase food supplies. </li></ul><ul><li>Opposite to Malthus – she suggested that population growth has enabled agricultural development to occur </li></ul><ul><li>Assumes people knew of the techniques required by more intensive systems and used them when the population grew. </li></ul>
  36. 38. i.e….. <ul><li>Demographic pressure (population density) promotes innovation and higher productivity in use of land (irrigation, weeding, crop intensification, better seeds) and labour (tools, better techniques). </li></ul>
  37. 39. Was she right? <ul><li>Boserup argued that the changes in technology allow for improved crop strains and increased yields. </li></ul><ul><li>GM crops </li></ul><ul><li>‘Green revolution’ </li></ul>
  38. 40. But…. <ul><li>Boserup admits overpopulation can lead to unsuitable farming practices which may degrade the land </li></ul><ul><li>e.g. population pressure as one of the reasons for desertification in the Sahal region (so fragile environments at risk) </li></ul><ul><li>Boserup’s theory based on assumption of ‘closed’ society -not the case in reality (migration) </li></ul>