History of world human population growth and doubling time

1. WORLD HUMAN POPULATION
GROWTH WITH HUMAN HISTORY AND
DOUBLING TIME
Department of Ecology & Environmental Science
PRESENTED BY
Biswajit Das (2014-16)

2. INTRODUCTION
Population growth is the change in a population over time and can be
quantified as the change in the number of individuals of any species in a
population using “per unit time” for measurement.
The total number of human currently living on Earth is now greater than
7.4 billion estimates by the United States Census Bureau(USCB) in 2016.
World population has experienced continuous growth since the end of
the Great Famine and the Black Death in 1350 A.D, when it was near
370 million.
Current projections show a continued increase in population in the near
future the global population expected to reach between 8.5b and
10.9billion by 2050.

3. POPULATION GROWTH RATES
 In biology, population growth is the increase in the number of
individuals in a population in a particular time.
 Global human population growth amounts to around 75 million
annually, or 1.1% per year. The global population has grown from 1
billion in 1800 to 7 billion in 2011 and it keep growing.
 Population growth rate for a particular country is determined by
four factors, births(B), deaths(D), immigration rate(I) and emigration
rate(E):
Growth rate of Population = B-D+(I-E)

4. HUMAN POPULATION GROWTH
 Globally, the growth rate of the human population has
been increase since peaking in 1962 and 1963 at 2.2%
per annum.
 In 2009, the estimated annual growth rate was 1.1%.
 The CIA World Factbook gives the world annual
birthrate, mortality rate, and growth rate as 1.86%,
0.78%, and 1.08% respectively.
 The last 100 years have seen a rapid increase in
population due to medical advances, illiteracy,
unawareness and massive increase in agricultural
productivity made possible by the Green Revolution.
Population
Years Passed Year(Billion)
- 1800 1
127 1927 2
33 1960 3
14 1974 4
13 1987 5
12 1999 6
12 2011 7
14 2025* 8
18 2043* 9
40 2083* 10
* UNFPA
United Nations Population Fund
estimate 31.10.2011

5. HISTORY OF WORLD HUMAN
POPULATION GROWTH
Anthropologists believe the human species dates back at least 3 million years.
For most of our history, these distant ancestors lived a precarious existence
as hunters and gatherers. This way of life kept their total numbers was small,
probably less than 10 million.
WORLD POPULATION UPTO 1650
 No reliable data is available.
 According to one estimate, the population in 10000B.C. was just 50lakhs.
 Growth rate of early historical time was just 0.002% per annum which is double to the
population in 35000years.
 World population in the year 1000A.D. was estimated at 27.5 crores. After that it continued
to increase.
 In 1650, the world population was 48.6 crores.

6. WORLD POPULATION BETWEEN 1650 AND 1800 A.D.
 Real agricultural revolution began after 1700 A.D.
 There was significant developments in transport, communication, mining and
manufacturing technology during 18th century.
 In 1800 A.D. world population was 90 crores and Growth rate was 0.45% per annum
giving the doubling time of 190 years.
 Out of these 90 crores, about 60 crores were living in Asia, 22 crores in Europe, 7
crores in Africa and rest in America & Oceania.

7. WORLD POPULATION BETWEEN 1800 AND 1900A.D.
 Control of diseases, improvement in surgical technologies,
vaccination etc.
 The first billion of world population reached by 1800A.D.
 The second billion were added only in the next 127 years, i.e., by
1927.
 The world population growth rate was 0.6% per annum between
1850 and 1900 A.D.

8. WORLD POPULATION BETWEEN 1900 AND 1970 A.D.
 Decreasing Death rate and increase birth rate due to the
advanced in medical fields.
 In between the year 1900 to 1950, there was lots of peoples are
died because of World War one & two.
 In 1927 World population touched 2 billion, of which 1.05 billion
crores were in Asia.
 Population was growing between 1950 and 1970 at the rate of
2.6% per annum in South America, at 2.4% per annum in Asia and
Oceania.
 But in Europe and the USSR, the growth rate fell down to 0.8%
per annum, due to corresponding fall in the birth rates.

9. World population between 1970 and 2015
 World population was estimated at 410 crores in the year 1978
and 440 crores by the end of 1981.
 The fifth billion were added in just 11 years i.e., by 1986 the world
population crossed 500 crores mark and by the year 1999 the
world population mark 600 crores.
 End of the year 2011 world population marked 7 billions.
 In most of the developing countries high birth rates and
comparatively less in developing countries.

10. THEORIES OF POPULATION
Right from the rise of human civilization, the
scholars did not agree on the population growth.
Early Rome was characterized by a fertility cult
and medieval period was the period of invasions
battle and war . The German scholar also
attributed the power of the states mainly to
population. The first thinker who took the
question of population in a formal way was
Malthus Thomas.

11. MALTHUSIAN THEORY OF
POPULATION GROWTH
Thomas Robert Malthus, the English economist
and demographer, is well known for his theory of
population growth.
 He published “An Essay on the principle of
populations as it affects the future
improvement of society in 1798”.
 Population growth tends to outstrip the
means of subsistence.
 Food increases arithmetically while
population increases geometrically.
Thomas Robert Malthus
(1766 - 1834)

12. overpopulation
Point of
crisis

13. MARXIAN THEORY OF
POPULATION GROWTH
 Marx was a thinker who made scientific
interpretation of human history.
 Marxian theory of population is based as a
reaction to the capitalistic mode of
production and governance.
 According to Marx, poverty and misery
were not natural inevitabilities but
unpleasant gift of capitalism.

14. It seems that the vast majority of people on this earth are blissfully unaware of
how fast the human population on our blue marble (Earth) has been exploding,
since the ‘Black Plague’.

15. STAGES OF HUMAN POPULATION
GROWTH
1. Stage one (preindustrial/pre-agricultural)
-Crude birth/death rate high
-Fragile, but stable population
2. Stage two (improved agriculture and medicine)
-Lower death rates
-Infant mortality rate falls
-Natural increase very high
3. Stage three (attitudes change)
-Indicative of richer developed countries
-Higher standards of living/education
-Crude birth rate finally falls
4.Stage four
-Crude birth/death rates low
-Population stable
-Populations aging

16. CAUSES OF RAPID GROWTH
 Advanced in medicine.
 Agricultural advances.
 Labor previously performed by
animals & now performed by
machines.
 Urbanization.
 Improvements in Sanitation.
 Adv. in Science & technology.
 Food production and distribution

17. REGIONAL DISTRIBUTION
 Population in certain regions grow, elsewhere
human number will stabilize or even decline.
 Within countries, population will continue to shift
from rural to urban areas, while becoming older
and increase better education.
 Migration between countries will be an
increasingly important factor in international
relation and the composition of national
population.

18. WORLD POPULATION
DISTRIBUTION BY REGION,
1800–2050

19. CURRENT WORLD POPULATION
Top countries in World Population in 2011
The most populated countries of the world.
Country
Human Beings (in
millions)
China 1,369
India 1,270
United States 321
Indonesia 255
Brazil 204
Pakistan 189
Nigeria 183
Bangladesh 158
Russia 146
Japan 126
Mexico 121
Philippines 101
Viet Nam (Vietnam) 91.5
Ethiopia 90.0

20. REGIONAL VARIATION WITH
DEVELOPMENTAL STATUS

21. POPULATION TREND
COMPARISONS
Developed Countries
 Low infant mortality rate
 Life expectancy 77 years
 Total fertility rate = 2.0
 21% population <15 age
 12% population >65 age
 Per capita GDP = $36,110
Developing Countries
 High infant mortality rate
 Life expectancy 52 years
 Total fertility rate = 5.7
 44% population <15 age
 3% population >65 age
 Per capita GDP = $800

23. DOUBLING TIME
The number of years required for the population of
an area to double its present size, given the
current rate of population growth. Population
doubling time is useful to demonstrate the long-
term effect of a growth rate, but should not be
used to project population size.

24. DOUBLING TIME OF POPULATION
IS APPROXIMATELY 14 YEARS.

25. EXPECTED DOUBLING TIME IN
DEVELOPED AND DEVELOPING
COUNTRIES
 Many developed countries have very low growth rates. But
these countries are not expected to ever double again.
 Many less-developed countries have high growth rates that
are associated with short doubling times, but are expected
to grow more slowly as birth rates are expected to
continue to decline.

26. FUTURE GLOBAL POPULATION
GROWTH
 According to a report from the United Nations Population
Fund ,based on 1988 analyses, projections for the future
global population are being revised downward.
 The projection for 2050 now is 8.9 billion, substantially
lower than 1996 projection of 9.4 billion.
 The most important factor is HIV/AIDS, which is spreading
much faster than previously anticipated. The HIV/AIDS
epidemic is having a devastating effect on Africa.

27. IMPACT OF CONTINUED GROWTH
AND IN ENVIRONMENT
 Increasing desertification and increased urbanization.
 Increased number of refugees.
 Emerging diseases
 Soil erosion
 Poaching
 Loss of biodiversity
 Increasing Air/Water pollution.
CHALLENGES
 Religion.
 Educate the people.
 Low female status.
 Preference for male children.
 Female Infanticide

28. CONCLUSION
 Human ecology promotes the idea
that humans are not to be excluded
as an unnatural part of ecosystem.
Human population exhibits an J-
shaped growth curve, and is
accelerating.
 Population growth rate are highly
dependent upon level of development.
 Most current and future growth is
taking developing countries, which
experienced only a partial
demographic transition.

29. REFERENCES
1. Dash , M.C. (1993) Fundamentals of Ecology, McGraw-Hill
Publishing Co., New Delhi.
2. Kormondy, E.J. (1996) Concept of Ecology (4th edition) prentice
Hall of India Pvt. Ltd., New Delhi.
3. Srivastava, O.S. (1996). Demography and population studies .
Vikas Publishing House, Pvt. Ltd, New Delhi.
4. http://en.wikipedia.org/wiki/World_population
5. http://www.prb.org/Educators/TeachersGuides/HumanPopulation/P
opulationGrowth.aspx