8.1 Human population dynamics

what are the demographic tools used for quantifying human population

crude birth rate (CBR), crude death rate (CDR), total fertility rate (TFR), doubling time (DT) and natural increase rate (NIR)

what happens to earth's systems as the human population grows

increased stress is placed on all of Earth's systems

what can be useful in the prediction of human population growth

age/sex pyramids and demographic transition models (DTM)

what is the DTM

a model which shows how a population transitions from a pre-industrial stage with a high CBR and CDR to an economically advanced stage with low or declining CBR and low CDR

what are the influences on human population dynamics

cultural, historical, religious, social, political, economic

what type of curve has the human population followed

an exponential curve

how long will it take for the population to double again

less than 100 years

how many humans life in poverty

about half

why are population estimates greatly varied

because they are based on past and current trends, it is difficult to predict human behaviour, it is hard to build in the impact of the demographic structure of the population

what is crude birth rate

the number of births per thousand individuals in a population per year

what is crude death rate

the number of deaths per thousand people per in a population per year

what is natural increase rate

the rate of human growth expressed as a percentage change per year

how is the natural increase rate calculated

(crude birth rate - crude death rate) / 10

what is doubling time

the time in years it takes for a population to double in size

what is the total fertility rate

the average number of children each woman has over her lifetime

what are the four main factors that affect population size of organisms

birth rate, death rate, immigration, emigration

what is replacement fertility

2.03 in MEDCs and 2.16 in LEDCs because of infant and childhood mortality

what is the difference between birth rate and fertility

birth rate is expressed as a percentage of the total population, not of each woman

give some characteristics of MEDCs

most countries in europe, north america, south africa, israel, and japan, industrialized nations with high GDPs, population is relatively rich, individuals are unlikely to starve through poverty, relatively high level of resource use per capita, relatively low population growth rates, have very high carbon and ecological footprints

what are the characteristics of LEDCs

most of the countries in sub-saharan africa, large areas of asia, and south america, less industrialized or have hardly any industry at all, many have raw materials but this tends to be exported and processed in MEDCs, population has a lower GDP and higher poverty rates, more people are poor with low standards of living, high population growth rates, have lower carbon and ecological footprints

what are newly industrialized countries

those that have accelerated their industrial development and increased GDP, often accompanied by massive foreign investment, population migration to the cities to provide a workforce, free trade, and increased civil rights

which countries are considered to be newly industrialized

China, India, South Africa, Mexico, Brazil

why is the human population causing an environmental impact

more people require more resources, more people produce more waste, people usually want to improve their standard of living

what is demography

the study of the statistical characteristics of human populations

when do populations remain stable

when the death rate and birth rate are equal and so there is no net gain in population size

how does resource use vary in time and space

MEDCs and LEDCs demonstrate contrasting resource use per capita, urban and rural populations demonstrate varying resource use profiles, young people have different resource needs to the elderly, Amazonian tribes have different resource needs than parisians

what percentage of people live in MEDCs

20%

what percentage of people live in LEDCs

80%

what did thomas malthus believe was the main limit to population growth

food supply

how did malthus believe that human population increased

he believed that the human population increases geometrically whereas food supplies can grow only arithmetically, being limited by available new land, the laws of nature dictate that a population can never increase beyond the food supplies necessary to support it

what serves as the check to population growth in malthusian theory

the law of diminishing returns, where, even with higher levels of technology, only a small increase in yield will occur

what are the limitations of malthusian theory

it ignores the fact that the reality is only the poor will go hungry, malthus could not have foreseen the changes in farming technology that mean we can produce vast amounts of food

what was boserup's theory of population growth

Population growth would continue, When the amount of population and resources were close, humans would invent a technological innovation to prevent crisis, Population and resource production would both continue to grow.

what are the limitations of boserup's theory

relies on the assumption of a closed community, overpopulation can lead to unsuitable farming practices that may degrade the land so population pressure may be responsible for desertification in the sahel

what may reinforce malthusian ideas

the growing suffering and famine in some LEDCs

why can both malthus and boserup be right

because malthus refers to the environmental limits while boserup refers to cultural and technological issues

what would the world population be in 2100 if the fertility rate dropped to 1.5

3.6 billion

what would the population be in 2100 if the fertility rate was 2.0

10.1 billion

what would the world population be in 2100 if the fertility rate was 2.5

15.8 billion

what is the total world fertility rate

about 3.0

what is the average fertility rate in MEDCs

1.7

what is the fertility rate in LEDCs

an average of 3.4 but up to 6.0

what is the optimum population of a country

when the population produces the highest economic return per capita, using all available the resources

why do people have large families

high infant and child mortality, security in old age, children are an economic asset, the status of women, unavailability of contraceptives

why might have someone have a large family due to high infant and childhood mortality

it is an insurance to have more children than you may need so that some of them reach adulthood

why might someone have a large family to have security in old age

the tradition in the family is that children will take care of their parents, the more children the more secure the parents, and the less the burden for each child

why might someone have a large family because children are an economic asset

in agricultural societies, they work on the land as soon as they are able, more children mean more help but children need feeding, in MEDCs, children are dependent on their parents during their education and take longer to contribute to society

why might the status of women cause someone to have a large family

the traditional position of women is that they are subordinate to men, in many countries, they are deprived of many rights like owning property, having their own career, getting an education, instead they do most of the agricultural work and are considered worthy of only making children and their social status depends on the number of children they produce, particularly boys

what are some ways to reduce family size

provide education, improve health, make contraceptives available, enhance income, improve resource management

what is the demographic transition model

the pattern of decline in mortality and fertility of a country as a result of social and economic development

what is stage one of demographic transition

high stationary, high birth due to no birth control, high infant mortality rates, cultural factors encouraging large families, high death rates due to disease, famine, poor hygiene and little medicine

what is stage two of demographic transition

early expanding, death rate drops as sanitation and food improve, disease is reduced so lifespan increases, birth rate is still high so population expands rapidly and child mortality falls due to improved medicine

what is stage three of demographic transition

late expanding, as a country becomes more developed, birth rated also fall due to access to contraception, improved healthcare, education, emancipation of women, population begins to level off and desire for material goods and low infant death rates mean that people have smaller families

what is stage four in the demographic transition

low stationary, low birth and death rates, industrialized countries, stable population sizes

what is stage five in the demographic transition

declining, population may not be replaced as fertility rate is low, problems of ageing workforce

what are the limitations of the demographic transition model

the initial model was without the fifth stage which has only become clear in recent years, the fall in the death rate has not always been as steep as this suggests movement from the countryside to cities has created large urban slum areas which have poor or no sanitation and consequent high death rates of the young and infirm, deaths from AIDS related diseases may also affect this, the fall in the birth rate assumes the availability of contraception and that religious practices allow for this, it also assumes increasing education and literacy rates for women, some countries have compressed the timescale of these changes, this is a eurocentric model and assumes that all countries will become industrialized

what are some policies that may reduce population growth rates

governments introducing pension schemes, paying more tax to have more children, increased access to education and methods of birth control, urbanization as fewer people can live in smaller urban accomodation, education women to have greater personal and economic independence

what are some policies that may increase population growth rate

agricultural development, improved public health and sanitation, lowering income tax or giving free education and healthcare, encouraging immigration