Judging the Relevance and worth of ideas part 2.pptx
Population growth and its effects on environment
1. Population Growth & its
effects on environment
• Population growth ,
variation among nations
• Global population
growth
• Family Welfare
Programme
• Methods of sterilisation
• Urbanisation
3. INTRODUCTION
What does Population actually
means ???
In general , a term for the number of people living
in an area at a particular time .
How can Population Growth be
defined ???
The change in population over time and can be
quantified as the change in number of individuals in
a population us “per unit time”. The term Population
4. The
Focus• Human population impacts environment science in many ways:
• Rising populations put increasing demands on natural resources such a
land, water, and energy supplies.
• As human communities use more resources, they generate
contaminants, such as air and water pollution and greenhouse ga
emissions
• They also increase larger quantities of waste
Focus of study on Demography, the science of human population. We sha
explore environmental impacts of population growth and also consider
questions such as:
•How does population growth or decline influence economic and socia
well-being
•Does population growth enhance or diminish economic growth?
5. • Estimate Earth's carrying capacity? or the maximum
population that it can support on a continuing basis.
• Dependencies:
• Food production
• Total arable land
• Amount of energy available to do work
• Resources are not allocated equally around the world. In some
areas such as the Sahel in West Africa (between the Sahara desert
and more humid woodlands to the south), population growth is
putting heavy stresses on a fragile environment, so food needs
are outstripping food production
.
6. Population(inmillion)
Source : UNPD , 2004
THE EARLY
SPURFig. 1 : Past and Projected human population.
Population growth rate .
• Birth and death rates are the most important determinants of population growth; in
some countries, net migration is also important in this regard.
• To calculate population growth rates, demographers take the difference between births
and deaths in a given time period, add the net number of migrants (which for the world
as a whole is 0), and divide that number by the total population.
• For example, there are now about 136 million births and 58 million deaths worldwide
annually, adding a net of 78 million new inhabitants to a global population of 6.7 billion,
a growth rate of nearly 1.2%
7. GLOBAL POPULATION
GROWTH
When the birth rate is higher than the death rate, more people are being
born than are dying, so the population grows
This is called Natural increase
When the death rate is higher than the birth rate it is called the natural
decrease.
The worlds population is growing rapidly
The population of the world is growing at an
exponential rate- its growing faster and faster.
There are two things that affect the population
size of the world
Death rate-the number of deaths per
thousand of the population per year
Birth rate- the number of live babies
born per thousand of the population per
year.
8. increase, parents can become increasingly confident that fewer children will suffice to help in family business
and care for them in old age.
• Increasing urbanization changes the traditional values placed upon fertility and the value of children in rural
society. Urban living also raises the cost of dependent children to a family. A recent theory suggests that
urbanization also contributes to reducing the birth rate because it disrupts optimal mating patterns. A 2008
study in Iceland found that the most fecund marriages are between distant cousins. Genetic incompatibilities
inherent in more distant out breeding makes reproduction harder.
• In both rural and urban areas, the cost of children to parents is exacerbated by the introduction of compulsory
education acts and the increased need to educate children so they can take up a respected position in society.
Children are increasingly prohibited under law from working outside the household and make an increasingly
limited contribution to the household, as school children are increasingly exempted from the expectation of
making a significant contribution to domestic work. Even in equatorial Africa, children now need to be clothed,
and may even require school uniforms. Parents begin to consider it a duty to buy children books and toys.
Partly due to education and access to family planning, people begin to reassess their need for children and
their ability to raise them.
A major factor in reducing birth rates in stage 3 countries such as Malaysia is the availability of family planning
facilities, like this one in Kuala Terengganu, Terengganu, Malaysia.
• Increasing female literacy and employment lower the uncritical acceptance of childbearing and motherhood as
measures of the status of women. Working women have less time to raise children; this is particularly an issue wher
fathers traditionally make little or no contribution to child-raising, such as southern Europe or Japan. Valuation of
women beyond childbearing and motherhood becomes important.
• Improvements in contraceptive technology are now a major factor. Fertility decline is caused as much by changes i
values about children and sex as by the availability of contraceptives and knowledge of how to use them.
The resulting changes in the age structure of the population include a reduction in the youth dependency ratio and
eventually population ageing. The population structure becomes less triangular and more like an elongated balloon.
During the period between the decline in youth dependency and rise in old age dependency there is a demographic
window of opportunity that can potentially produce economic growth through an increase in the ratio of working age
9. However, unless factors such as those listed above are allowed to work, a society's birth rates may not drop to
a low level in due time, which means that the society cannot proceed to Stage Four and is locked in what is
called a demographic trap.
to dependent population; the demographic dividend.
Countries that have experienced a fertility decline of over 40% from their pre-transition levels include: Costa
Rica, El Salvador, Panama, Jamaica, Mexico, Colombia, Ecuador, Guyana, Surinam, Philippines, Indonesia,
Malaysia, Sri Lanka, Turkey, Azerbaijan, Turkmenistan, Uzbekistan, Egypt, Tunisia, Algeria, Morocco, Lebanon,
South Africa, India, Saudi Arabia, and many Pacific islands.
Countries that have experienced a fertility decline of 25-40% include: Honduras, Guatemala, Nicaragua,
Paraguay, Bolivia, Vietnam, Myanmar, Bangladesh, Tajikistan, Jordan, Qatar, Albania, United Arab Emirates,
Zimbabwe, and Botswana.
Countries that have experienced a fertility decline of 10-25% include: Haiti, Papua New Guinea, Nepal,
Pakistan, Syria, Iraq, Libya, Sudan, Kenya, Ghana and Senegal.
Effects on Age Structure
The decline in death rate and birth rate that occurs during the demographic transition leads to a radical
transformation of the age structure. When the death rate declines during the second stage of the transition, the
result is primarily an increase in the child population. The reason is that when the death rate is high (stage
one), the infant mortality rate is very high, often above 200 deaths per 1000 children born. When the death rate
falls or improves, this, in general, results in a significantly lower infant mortality rate and, hence, increased child
survival. Over time, as cohorts increased by higher survival rates get older, there will also be an increase in the
number of older children, teenagers, and young adults. This implies that there is an increase in the fertile
population which, with constant fertility rates, will lead to an increase in the number of children born. This will
further increase the growth of the child population. The second stage of the demographic transition, therefore,
implies a rise in child dependency.
10. Consequences :-
Most worldwide population growth happened in past 200 years;
• First billion reached in 1804, sixth billion in Oct. 1999.
World population growth is stabilizing;
• Highest growth rate (2.04%) in late 1960s; now at 1.31% .
• U.N. projects world pop. stabilizing at 10 billion after 2200 .
Growth rates vary among nations;
• Most growth is in developing (stage 2) nations.
• Some stage 3 nations approach zero population growth (ZPG).
Age structures and sex ratios vary among nations.
Critical Evaluation :-
It has to be remembered that the DTM is only a model and cannot necessarily predict the future. It does
however give an indication of what the future birth and death rates may be for a country, together with the total
population size. There are therefore limitations to it as with any model. Most particularly, of course, the DTM
makes no comment on change in population due to migration.
Conclusion :-
The demographic transitions that swept the world in the course of the last century has been identified as
one of the prime forces in the transition from stagnation to growth. It brought about significant reduction in
fertility rates and population growth in various regions of the world, enabling economies to convert a larger
share of the fruits of factor accumulation and technological progress into growth of income per capita.
Various mechanisms have been proposed as possible triggers for the demographic transition, and thus as
a catalyst in the transition from stagnation to growth. Empirical evidence, however, suggests that the
increasing role of human capital in the production process in the second phase of the Industrial Revolution
was the central force behind the demographic transition. Unlike episodes of technological progress in the
pre-Industrial Revolution era that failed to generate sustained economic growth, the onset of the
demographic transition liberated the gains in productivity from the counterbalancing effects of population
growth paving the way for human capital formation and the emergence of the modern state of sustained
economic growth.
13. Fig.1 shows, the world population grew very slowly until 1750.
Around 1750, at the drawn of Industrial Revolution. The world
population was approx. 800 million.
Until this time, the world population was
kept in check by high mortality. After 1750, the world
population grew substantially; by 1950, it had tripled around
2.5 billion.
After this,
duration of doubling time has decreased & also duration of
billion addition decreased (as shown in fig. 2 & 3).
Period Population Time Span
10,000 BC. 5 million -
1650 AD. 500 million 1500 yrs.
1850 AD. 1000 million 200 yrs.
1930 AD. 2000 million 80 yrs.
1975 AD. 4000 million 45 yrs.
2012 AD. 8000 million 37 yrs.
Source : UNPD
14. World population is estimated cross the six billion threshold on Oct. 12th 1999.
World population is projected to cross the 7 billion mark in 2013; the 8 billion mark in
2028; the 9 billion mark in 2054.
World population nearly stabilizes at just above 10 billion after 2200.
It has taken just 22 yrs. for the world to add this most recent billion people. This is the
shortest period of time in the world history for a billion people to be added.
World population did not reach one billion until 1804. It took 123 yrs. to reach 2 billion in
1927, 33 yrs. to 3 billion in 1960, 14 yrs. to reach 4 billion in 1974 and 13 yrs. to reach 5
billion in 1987.
The highest rate of world population growth (2.04 %) occurred in the late 1960s. The
current rate (1995 – 2000) is 1.31 % .
The largest annual increase to world population (86 million) took place in the late 1980s;
the current annual increase is 78 million.
THE
WORLD AT
BILLION :
HIGHLIGHT
S
15. Of the 78 million people currently added to the world each year, 95% live in the less
developed regions.
80% of the world currently resides in the less developed regions. At the beginning o the
century, 70% did so. By 2050, the share of the world population living in the currently less
developed regions will have risen to 90%.
The number of people in the world aged 60 or older will also rise from the current one – of –
ten persons to be two – of – nine by 2050.
Currently around one – of – five persons in the developed countries are aged 60 or older; in
2050 nearly one – of every – three persons will be aged 60 or older.
World life expectancy at birth is now at 65 yrs , having increased by a remarkable 20 yrs since
1950; by 2050 life expectancy is expected to exceed 76 yrs. However, in spite of these impressive
gains, recent years have shown devastating toll from AIDS in a number of countries.
In addition, in some Eastern European Countries, health has been deteriorating and mortality,
particularly among adult males, has been rising.
Couples in developed countries today have on an average 3 children each, 30 yrs ago they had
six. More than half of all couples in the developing countries now use contraception.
The number of persons who have moved to another country has rise to above 120 million
migrants today from 75 million in 1965.
The world has become increasingly urban. Currently, around 46 % of the world population
lives in urban areas; the majority of the world’s population will be urban by 2006.
Source : Population Division, UN.
22. Countries with population 100 million or more,1950
Country Population (in
1000)
% of world
population
1. CHINA 554,760 22.0
2. INDIA 357,561 14.2
3. U S A 157,813 6.3
4. RUSSIA 102,192 4.1
( SOURCE :- Population Division, UN)
23. Countries with a population of 100 millions or more
Countries Population(in 1000) % of
world
1. China 1,226,838 21.2
2. India 998,056 16.7
3. USA 276,218 4.6
4. Indonesia 209,255 3.5
5. Brazil 167,988 2.8
6. Pakistan 152,331 2.5
7. Russia 147,196 2.5
8. Bangladesh 126,947 2.1
9. Japan 126,505 2.1
10. Nigeria 108,945 1.8
( SOURCE- POPULATION DIVISION, UN , 1999)
24. Distribution of the world urban population by major area, 1950, 2007, 2050
( Source – Population Division, UN )
27. POPULATION GROWTH IN INDIA
Size, Growth Rate and Distribution of Population
INTRODUCTION :-
The first census was taken in India in 1871, and thereafter once every 10 yrs. It is, therefore ,
possible to study change in population size, structure, characteristics and other aspects during
the last 139 yrs. The estimates of population size in India during the ancient, medieval and the
early modern periods have been derived by Kingsley Davis from a careful examination of
archeological evidence, relevant literature that and historical records left behind by scholars of
history. The ensuing discussion on the growth of population in India from the ancient times upto
1900 draws heavily on the scholarly work of Kingsley Davis.
POPULATION GROWTH UPTO 1600 AD. : Since the ancient times, India has had the legacy of a
thickly settled population. The excavations at Harappa and Mohenjo-Daro reveal that. It appears
that even 3000 – 7000 yrs. ago, India possessed adequate technological knowledge to support a
dense population. The available record for the first truly Indian empire, under the rule of
Chandragupta Maurya almost three centuries BC., reveal that this empire could maintain a
standing army of about 700,000 men. It may well be presumed from this that a substantial
28. Population must have been required to maintain such a large army . Putting together all the
available evidence, Davis asserts, “Before the Christian Era, India had a substantial
population, first because of its advanced technology and second because of the fertile
environment for the application of this technology”.
POPULATION GROWTH FROM 1600 – 1870 : It is our misfortune that very little
documentary evidence is available on the basis of which estimates of population size for
the period of 1600 – 1870 may be made. This is probably because of census which was
done reason wise not country as a whole that’s way we do not get accurate statistics and
different aspects about the population. Heavy reliance has, therefore, to be placed on the
impressions of the Europeans who, during this period, visited India or stayed in India for
different periods of time for either trade or military purposes. Davis, while attempting to
reconstruct the growth of population in India during the period of 1660 – 1870 on the basis
of all available evidence, has finally arrived at the conclusion that “there is little use trying
to puzzle out India’s growth rate prior to the census period. The best policy is to revise
Moreland’s figure for 1600 upward to 125 million, ant to assume that the population
remained at this point for one and half centuries more, after which a gradual enhancement
of growth began, accelerating as 1870 approached”.
POPULATION GROWTH FROM 1871 – 1901 : From 1871 onwards, the base for the study of
the population of India is more firm, for actual accounts rather than only estimates, are
available. These actual counts, however, cannot be accepted as reliable because, with each
census, additional territories were covered and improvements effected in the methodology
29. Year % change from
previous decade
1881 0.9
1891 9.4
1901 1.0
1910 5.7
of conducting a census. The necessary adjustments
in the total population figures have, therefore,
been made.
The population count for 1867 – 1871 was 203.4
million, while the adjusted figure was 255.2
million. The growth rate of India’s population,
computed on the basis of adjusted figures,
indicates that between 1867 – 71 and 1881, population increased at the rate of 0.9 % , while
during 1881 – 91, it increased by 9.4 %. In the next decade (1891 – 1901), however the
growth rate went down to 1 %. The fluctuations in the rates of growth may be evaluated
from the (table a1.).
POPULATION GROWTH IN THE TWENTIETH CENTURY – Table a2., presents the growth of
India’s population from 1901 to 2001. It may be noted that the figures have been adjusted
for the territorial changes which occurred because of the partition of the Indian sub-
continent into two countries, India and Pakistan. The census figures for 2001 refer to the
population of India as recorded at 00.00 Hours of March 1, 2001. It may, however, be noted
that the enumeration was not carried out in Jammu And Kashmir. The provisional figure of
the total population as recorded in the 1991 census, however, includes the projected
population of Jammu And Kashmir.
Table a1. : Growth Rates
Source : Census of
India
30. Census
Year
Population Decadal
Absolute
Growth
(%)
Avg. Ann.
Expo.
Growth
Rate %
Progressive Growth Rate
Over 1901 (%)
1901 238,396,327 _ _ _ _
1911 252,093,390 13697063 5.75 0.56 5.75
1921 251,321,213 -772177 -0.31 -0.03 57.42
1931 278,977,238 27656025 11 1.04 17.02
1941 318,660,580 39683342 14.22 1.33 33.67
1951 361,088,090 42427510 13.31 1.25 51.47
1961 439,234,771 78146681 21.64 1.96 84.25
1971 548,159,652 108924881 24.80 2.20 129.94
1981 683,329,097 135169445 24.66 2.22 186.64
1991 846,387,888 163058791 23.86 2.14 255.03
2001 1027015247 180627359 21.34 1.93 330.80
Table a2. – POPULATION GROWTH IN INDIA 1901-2001
Source : Census Of India, 2001
31. OBSERVATIONS FROM TABLE a2 :
a) The course of population growth upto 1921 was undulating. The decades of
marked increases regularly alternated with decades of small increases, while
during 1911-21 a negative growth was experienced.
b) The absolute number of people added to the population during each decade
has been on the increase since 1921.
c) The decennial rate of growth has also increased from 1921 upto 2001. From
1951 onwards, India’s population has been growing at a phenomenal rate.
While during 1941 to 1951, the average decennial growth rate was 13.31 % ,
during 1951-61 it increased to 21.6% during 1961-71 it was 24.8%. From
1901-2001 there has been an increase of 330.8% in the population. India’s
population has more than doubled in a period of 50 years, i.e., from 1921-71.
d) It can be noticed from table a2 that the decennial population growth rate
during 1961-71 was 21.80%, during 1971-81 it was 24.66%, during 1981-91 it
was 23.85% and during 1991-2001 it was 21.34%. Thus, it can be observed
that the rate of population growth has decreased during 1981-91 and 1991-
2001.
32. CURRENT POPULATION SITUATION IN INDIA :
India’s population growth during the twentieth century can be classified into the
following four distinct phases :
1901-1921 : Stagnant population
1921-1951 : Steadygrowth
1951-1981 : Rapidhighgrowth
1981-2001 : Highgrowthwithdefinite
signsofslowingdown
35. PROSPECTS FOR POPULATION GROWTH IN INDIA : It must be emphasized of population
growth in India, which is already over – populated, will depend mainly on the reproductive
behavior of the people. Though the death rate has considerably declined over the yrs., there
is a scope for even further decline, in which case there is all the more reason why the birth
rate should correspondingly decrease. A further reduction in birth rate will certainly depend
on the effectiveness with which family planning programme, recently renamed the family
welfare programme is implemented.
36. REFERENCES
Books :
Human Geography – Penguin Dictionary
Geography Of Population - R.C. Chandna
Principles of Population Studies – Asha A. Bhende & Tara Kanitkar
Human Geography – Majid Hussain
Population Geography – Dr. L.R. Singh
Websites :
www.un.org
www.datafinder.worldbank.org
www.mapsofindia.co.in
www.censusofindia.org
www.wikipedia.org
www.uscb.org
www.demographictransition/filetype:pdf.edu