POPULATION DYNAMICS

TOPIC 3: HUMAN POPULATION, CARRYING CAPACITY AND RESOURCE USECh.3.1 Population DynamicsCh.3.2 Resources-natural capitalCh.3.3 Energy ResourcesCh.3.4 The Soil SystemCh.3.5 Food ResourcesCh.3.6 Water ResourcesCh.3.7 Limits to growthCh.3.8 Environmental Demands of Human Populations

POPULATION DYNAMICS1. EXPONENTIAL GROWTH in human populn.2. Recent DEMOGRAPHIC CHANGES3. The Concept of EXPONENTIAL GROWTH4. CRUDE BIRTH & DEATH RATES, FERTILITY, DOUBLING TIME AND RATES OF NATURAL CHANGE

5. AGE-SEX PYRAMIDS and the Model of DEMOGRAPHIC TRANSITION6. Models and predicting the growth of Human Populations7. POPULATION PROJECTIONS & UN 2010 REVISION

1. EXPONENTIAL GROWTH IN HUMAN POPULN.

WORLD POPULATION NOS. (2011)WORLDMEDCsLEDCsPOPULATION6.98 b1.24 b5.74 bBirths peryear13.95 b1.4 b12.54 bday382 35138 548343 803minute26627239Death perYear56.6 m12.2 m44.4 mday155 09933 427121 671minute1082384Natural Increase(Births-Deaths) peryear82.94 m1.86 m81.07 mday227 2525121222 132minute1584154Infants deathsperyear6.07 m77 0006 mday16 6522111 644minute12.10.111

2. RECENT DEMOGRAPHIC CHANGEMEDCs, LEDCs and POPULATION GRThe total populn. and the rate of populn. Gwth are much higher in LEDCs than MEDCs.MEDCs:high populn. gwth in 19th and early 20th cent.LEDCs:high populn. gwth since 1950Refer next ppt slidePopulation Explosion-Highest global popul GR reached in 1960s in LEDCs : 2.4% By late 1990s:GR declined to 1.2%Population Momentum: Numbers being added each yr.

DEMOGRAPHIC TRANSFORMATIONtook a cent. to complete in MEDCs, occurred in a generation in some LECDsFertility: dropped, except Africa- GR 2.5% ,>20 count families of at least 5 children.China and India, 37% of worlds populn.Indias popul GR faster, overtake Chinas popul by 2030

TEN MOST POPULOUS COUNTRIES IN THE WORLD 2011

20112050COUNTRYPopuln./millionCOUNTRYPopuln./million1.CHINA1346INDIA16922.INDIA1241CHINA13133.US312NIGERIA4334.INDONESIA238US4235.BRAZIL197PAKISTAN3146.PAKISTAN177INDONESIA3097.NIGERIA162BANGLADESH2268.BANGLADESH151BRAZIL2239.RUSSIA143ETHIOPIA17410.JAPAN128PHILLIPPINES150

3. THE CONCEPT OF EXPONENTIAL GROWTHEXPONENTIAL GROWTH(EG) occursWhen GR of a mathematical function is ~ function's current valueMeans increase in no. or size at constantly growing rate.

MALTHUSIAN THEORYBy Revd Malthus(1766-1834)Said-crux of popul problem tendency in mankind to increase,-if unchecked beyond the possibility of an adequate supply of food in limited territoryTwo basic principles-popul grows at a Geometric rate(1,2,4,8 etc)-food prodn increases at Arithmetic rate(1,2,3,4 etc)In time,popul outsrip food supply until a catastrophe occurred ex famine,disease,war-limiting factors maintain a balance b/n popul & resource in long termLimitations- applicable to old period,200 yrs ago- tech advances unfold,ex agric.(fertiliser,HYV etc)

PAUL EHRLICH and NEO MALTHUSIANSPAUL EHRLICH-Follower of Malthus, -warned, the potential mass starvation in 1970s-80s-advocate,immediate action to limit popul growth-heavily criticised, inaccurate predictions.NEO MALTHUSIANS, argue that expanding popul lead to unsustainable pressure on food & other resources.In recent yrs highlighted-steady Global decline in farmland/person-steep rise in cost of food products-growing scarcity of fish in many parts-impact of climate change on agriculture-switchover, food pdn to biofuel,create food crisis to reduce energy crisis-increase in world popul-global increase in meat consumption,rise in new NICs

NEO MALTHUSIANS VS ANTI MALTHUSIANS-reference Next ppt. slideANTI MALTHUSIANS or Resource Optimists believe human ingenuity will continue to conquer resource problems, through -development of new resources-replacement of less efficient with more efficient resources-rapid dev of green tech thru R&D-imp advances in agric research-stabilising levels of consumptions in some MEDCs

4. CRUDE BR & DR, FERTILITY, DOUBLING TIME AND RATES OF NATURAL INCREASECBR & CDRCBR=no. of live births/countrys popul * 1000 CDR=no. of deaths/countrys popul * 1000-crude means BR & DR applies to the total popul-taking no a/c of gender and age-CBR & CDR are heavily influence by age structure-in CBR,the male popul is considered together with female popul

CALCULATIONS (BR,DR & RATE OF NATURAL CHANGE (RNC)Example:for a country-If BR is 15 per 1000 and DR is 10 per 1000-means 15 births per 1000 & 10 deaths per 1000-diff b/n BR & DR is RNC-(15 per 1000 10 per 1000)=5 per 1000 is RNC RNC can be Positive(Increase) or Negative(Decrease) -Natural Increase when, BR>DR-Natural Decrease when, DR>BRRNC can also be expressed as %-in ex above RNC 5 per 1000, or 0.5%

Some facts -Africa, highest BR (36 per 1000 as per 2011)-Europe, lowest BR (11 per 1000 as per 2011)-Africa BR ,3 1/2 times that of Europe-Global Variations in DR, much less(12/1000 in Africa,6/1000 in Europe)-High Variations in BR,(48/1000 in Niger, 7/1000 in Monaco/Taiwan)-sixteen countries in Africa, CBR 40/1000-Europe BR=DR, zero RNC (0.0%)

CRUDE BIRTH and DEATH RATES, 2011

FR & TFRFR -is the no. of live births per 1000 women (15-44 yrs) in a given yrTFR-is the avg no. of children that would be born alive to a woman (or group of women) during her lifetime-TFR varies as high of 7.0(Niger), as low as 1.0 (China,Macao & Hongkong)

CRUCIAL FACTORS IN FERTILITY% of young women of reproductive ageReplacement level fertility(RLF)-level at which each generation has just enough children to replace themselves in the popul-level varies for diff popul-a TFR of 2.12 is usually considered as RLF

ANALYSIS ABOUT RLF FROM ABOVE TABLEwith global fertility decline-a growing no. of countries reached or fallen below RLF-by 2011 >80 countries had TFR = or < 2.1-this no is likely to increase in future

MAP OF TFR,2008

CALCULATING FRTotal live births in a country in a yr 1000total females (15-44yr) at mid point of yrCALCULATING TFRTake % of women of any given age(ex 17,18,19) who had a child in a yrAdd all these figures togetherDivide by 100Ex the total % figure came to 175% the TFR would be 1.75Below table shows the summary of live birth statistics in England & Wales b/n 1999 & 2009, compares the BR,FR&TFR

DOUBLING TIMEDoubling Time-of a popul is the number of yrs it would take a popul to double its size at its current GR-determined by dividing 70 by the GR which is natural log of 2, which is 70ex In 2010, popul of a country 33 mill at GR 0.9% hence, popul DT=70/0.9=77.7 yrsso, in 2087 if current GR maintained,popul will be 66 millUseful in making international comparisonsHelps to understand the impact of popul growth on resources & the environment in generalHowever, popul GR can change significantly over time & thus figures ve to be revised on regular basis

5. AGE-SEX PYRAMIDS & THE MODEL OF DEMOGRAPHIC TRANSITIONTHE MODEL OF DEMOGRAPHIC TRANSITIONPopul of no two countries have changed in exactly the same waySome broad generalisations about popul GR since middle of 18th cent, illustrated in next ppt slide, based on N.W.EuropeThe first part of the world to undergo such changes as a result of industrial & agrarian advances during 18th & 19th centStage 1-remote societies viz isolated tribes in New Guinea & AmazonStage 2-the poorest of LEDCs (Niger,Bolivia),joined by some oil rich Middle East nationsStage 3-most LEDCs which ve registered significant social & economic advances (Brazil,China,India)Stage 4 or 5-All MEDCs,most having experienced all previous stages,also some NICs (S.Korea & Taiwan)

CHARACTERISTICS OF EACH STAGEThe high stationary stage(Stage 1)-CBR is high & stable, CDR is high & fluctuating (famine, disease, war)-popul GR is very slow, many periods of decline-IMR is high, life expectancy is low-max popul is female mortality-most rapid in poorest countries, due to high IMR higher among males than femalesA Report-China (2002), 116/100, due to female fetuses aborted, intent on male childDifferences with countries-ex US, highest in Alaska (103.2), lowest in Mississippi (92.2)

6. MODELS & PREDICTING THE GROWTH OF HUMAN POPULModels play a central rolein predicting the growth of human populSuch models include-computer simulations-statistical & demographic tables-age-sex pyramids-graphical extrapolation of popul curves

7. POPULATION PROJECTIONS & THE UN 2010 REVISIONPOPULATION PROJECTIONS Prediction of future popul based on the present age-sex structure, and rates of fertility/mortality/migration.Simplest projections based on estimation of current and past trendsVery diff projections based on different assumptions

PAST VS PRESENTEarlier Projections-analysis of statistical & demographic tables-popul pyramids,line graphs and other cartographic methods were used-to plot data & project into the future-dates back to 1945Modern Projections-computer tech -complex permutations included -frequent updations in projections -to reflect changes in fertility, mortality etc.

TYPES OF POPULATION PROJECTIONSDiffer widely in their-geographic coverage, time scale(sub national like city to whole world), content & useLocal area projections-shorter time scale for 10-20 yrsGlobal projections -extend for 25,50 or 100 yrsLonger term projections-limited no of variables (popul, age & sex)Smaller region projections-other variables as well (labour, household type)

POPULATION MOMENTUM IN POPULATION PROJECTIONOccurs in Stage 3 of DTAlthough GR falling in a country but increase in absolute no due to popul momentumHighest global GR in early 1960sHighest increase in popul in late 1980sPOPULATION PREDICTIONSDemographers, reasonably confident about near & medium term PP for Positive Momentum countries-because thru PM, much of future is built into the current structure of popul-considerable for very high fertility countries, even if the TFR fell sharply In Contrast, the low-fertility countries-viz Germany, Italy & Spain do not have PM-the PM of these popul has been dessipated by decades of fertility below the replacement level

PROJECTIONS FROM ASSUMPTIONSProjections result from assumptions, when they are prepared.Assumptions must be made about:-declines in the future BR-improvement in LE & IMR-migration into and out of an areaAny PP is hypothetical in nature.-always dangerous to assume that various demographic factors will stay same or will change marginally in future-significant demographic changes ve occurred since 1950 in both LEDCs & MEDCs-many previous PP ve proved inaccurate to a considerable degree-ex failure to foresee the baby boom after the end of WW2, and the end of this boom

Although total accuracy is almost impossible to achieve, PP need to be accurate enough to serve as basis for policiesD.A.Coleman states-Population matters because of its associated effects on power, environment & security arising from global & regional, and particularly differential, popul growth and compositionAnalysis of (ppt), three global Projections to 2050The central forecast expects world popul to stabilise at about 9 billThe upper line is the UNs high variant which assumes slow decline in fertility and faster increase in LEThe low variant line shows that the UN now takes seriously the possibility that world popul could actually decline before the end of the century.

THE UNITED NATIONS 2010 REVISIONThe world popul is expected to hit 10.1 bill by 2100 after reaching

Virtually all the growth will take place in LEDCs and will be predominately among the poorest popul in urban areasRefer Fig. shows-the popul pyramid for the world projected to change (2050 & 2100)-23% of people will be >65yrs or over (increase from 7.6% in 2010)-b/n 2011 and 2100, the popul of high- fertility countries (sub Saharan Africa), projected to triple from 1.2 bill to 4.2 bill-during same period, popul of intermediate fertility countries (India, US & Mexico), increase by just 26%-popul of low-fertility countries (Europe, China & Aus), decline by 20%-eventually popul of high-fertility countries forcast to decline until reaching replacement fertility by end of centuryHowever wider availability of family planning services and small variations in fertility produce considerable differences, in size of popul in long run.

1.What is the name given to the rapid growth of world population that has taken place since the industrial revolution?A. Population crashB. Population bombC. Population explosionD. Population bangE. Population dive2.What two words could be used to describe the growth of world population?A. ExponentialB. ArithmeticC. LogarithmicD. SteadyE. Constant

TIME:10 MIN. QUIZ ON POPULATION MM: 1*20

3.How is population density calculated?A. Area divided by populationB. Population divided by GNPC. Resource capacity divided by populationD. Population multiplied by areaE. Population divided by area

4.What is the geographic term for a country with a high population density?A. A densely populated countryB. An open countryC. An overpopulated countryD. A sparsely populated countryE. An under populated country

5.Which one of these countries is an example of a country with a high population density?A. CanadaB. BangladeshC. AustraliaD. USAE. Russia

6.What is the geographic term for a country with a low population density?A. A densely populated countryB. A closed countryC. An under populated countryD. A sparsely populated countryE. An overpopulated country

7.Which one of these regions is an example of a country with a low population density?A. The south east of the UKB. New Delhi in IndiaC. The Canadian NorthlandsD. The Japanese coastlineE. The Leeds Bradford conurbation in the UK8.Which one of these statements best describes the population distribution within the USA?A. The interior of the US generally has a high population densityB. The coasts of the US generally have a low population densityC. The US is sparsely populatedD. The US is densely populatedE. Some parts of the US are densely populated, other parts are sparsely populated

9.Which one of these statements best describes a theoretical situation where the number of resources match the population of an area?A.OverpopulationB.Optimum populationC.Under populationD.Dense populationE.Sparse population10.Which of the following statements is correct for the first stage of the demographic transition model?A. Birth rate high, death rate high and fluctuating, total population low and constantB. Birth rate high, death rate high, total population increasingC. Birth rate low, death rate high, total population low and constantD. Birth rate low, death rate low, total population lowE. Birth rate high, death rate low, total population low and constant

11.Which of the following statements is correct for the third stage of the demographic transition model?A. Birth rate high, death rate falling, total population increasingB. Birth rate low, death rate low, total population high and constantC. Birth rate falling, death rate high, total population increasingD. Birth rate falling, death rate falling, total population increasingE. Birth rate high, death rate low, total population high and constant12.Why is the birth rate low in stage four of the demographic transition model?A. Lots of people work in farming and there is a high infant mortality rateB. Hospital and sanitation facilities are starting to be developedC. Most people work away from farming in factories and are moving to the citiesD. Diseases spread rapidly in insanitary conditionsE. More women are working and consumerism means that the cost of raising children is very high

13.Why is the death rate high and fluctuating in stage one of the demographic transition model?A. Lots of people work in farming and there is a high infant mortality rateB. Hospital and sanitation facilities are starting to be developedC. Most people work away from farming in factories and are moving to the citiesD. Diseases spread rapidly in insanitary conditionsE. More women are working and consumerism means that the cost of raising children is very high14.Which one of these is not a problem associated with an overpopulated country?A. Lack of workers to exploit the country's natural resourcesB. Overcrowded citiesC. Lack of suitable housingD. DeforestationE. High unemployment and/or underemployment rates

15.When a population pyramid has a wide base it does not tend to have.A. A high birth rateB. A high death rateC. A low life expectancyD. An ageing populationE. A high infant mortality rate16.When a population pyramid has a narrow base it does not tend to have...A. A high fertility rateB. A low death rateC. A high life expectancyD. An ageing populationE. A low infant mortality rate

17.Which one of these is not a problem associated with an ageing societyA. Buildings have to be knocked down to make way for bungalowsB. Schools are overcrowded and many children must go without an educationC. Overcrowding within nursing homesD. Hospital waiting lists lengthenE. Nightclubs are forced to close down18.19.What name do we give to people who are too young or too old to workA. LazyB. DependentsC. ReliantsD. BenefitsE. Pensioners20.How does one calculate the natural increase of a populationA. Birth Rate + Death RateB. Death Rate x Birth RateC. Birth Rate - Death RateD. Birth Rate divided by Death RateE. Death Rate divided by Birth Rate