Population Growth and its consequences Flashcards
Since reaching 1billion pop. in 1800 what have we seen
exponential growth over the last 2 centuries
what is the rule of 70
Also referred to doubling time, divide 70 by the expected rate of growth an estimate in years is produced
what is population growth rate
rare at which no. individuals increases in a population over a given time. currently 1.09% a decrease foremother years
population is affected by what 3factors
births
deaths
migration(for country or regions)
crude birth or death rate =
no./1000peopl/year
what is replacement level fertilitiy
no. kids a couple has to replace themselves, 2.1 in high and 2.5 in low middle economic countries
why is replacement level fertility higher in lower economic countries
as some females die before reproductive years
what is total fertility rate
average no. kids born if a woman passed through reproductive years 15-44
latest estimate 2.4 uk-1.7
what are some factors effecting birth rate
education/affluence labour force urbanisation education and employment for women age of marriage birth control availability religion and culture
some factors effecting death rate
sanitation nutrition disease income urbanisation education health care
what is neo- malthusianism
pessimistic view on population growth, leads to unsustainable pressure on resources
anti-malthusianism
optimistic, human ingenuity will enable us to find solutions
hans rosling possibilitist idea
raise global standard of living means people have less children
what is demographic transition
from high birth and high death rates to low birth and low death rates as country becomes an industrialised economic system
differences after a demographic transition
lower birth and death rates
higher life expectancy
larger population
population growth low or declining]
what is epidemiological transition
long term shift in disease pattern form infectious towards degenerative
4 stages of demographic transition
1-pre modern
2-urbanising and industrialising
3-mature industrial
4-post industrial
key aspects of stage 1
high birth, infant mortality rate and death rate
young population
children as ‘insurance’
limited female education
key aspects of stage 2
death rates decrease rapidly
decrease in disease deaths and in infant mortality rates
still high birth rate
key aspects stage 3
growth levels off n stabilises education for women access to contraception urbanisation increases cost of having children ageing population
key aspects stage 4
low birth and death rates birth rates may drop below replacement rates
older age structure
proposed stage 5 aspects
industrial to service industry
below replacement rates
emigration
population decline
problems with demographic transition model
its complex not unidirectional and some countries take different paths
ie japan accelerated model
compression of mortality
more people die at small window at the upper limit of life
compression of morbidity
optimistic
live long healthy life die after short period of ill health
not likely as health declines gradually over years
extension of morbidity
people live longer but still in a long physiological state of decline with age leading to poor function and disease
evolutionary ageing
fewer beneficial genes for older age as reproduction happens young
wear and tear
body as a mechanical system breaks down over use
healthy ageing
slowing the rate of decline as age is associated with progressive generalised impairment of function
ER
life expectancy is different from life span, what have we seen in regards to this
upper limit of human life span not increasing rapidly, but more people are living longer increasing life expectancy
also many ‘natural deaths’ are hidden within complication or disease statistics
ER
Compression of morbidity aims to
compress the period of disease or senescence which in turn could reduce medical costs and have reduced illness burden on society
ER
smokers and drinkers often cost how much more than moderate users
4x more and tend to die earlier
ER
older populations are growing rapidly in which countries
at the moment europe has highest median age but in developing countries the ageing population is on track to explode over the next few decades especially in subsaharan africa
