WORLD HUMAN POPULATION GROWTH WITH HUMAN HISTORY AND DOUBLING

TIME

Department of Ecology & Environmental Science

PRESENTED BYBiswajit Das (2014-16)

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.

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)

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.

PopulationYears Passed Year(Billion)- 1800 1127 1927 233 1960 314 1974 413 1987 512 1999 612 2011 714 2025* 818 2043* 940 2083* 10* UNFPAUnited Nations Population Fundestimate 31.10.2011

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.

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.

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.

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.

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.

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.

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)

overpopulation

Point of crisis

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.

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’.

STAGES OF HUMAN POPULATION GROWTH

1. Stage one (preindustrial/pre-agricultural) -Crude birth/death rate high -Fragile, but stable population2. Stage two (improved agriculture and medicine) -Lower death rates -Infant mortality rate falls -Natural increase very high3. 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

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

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.

WORLD POPULATION DISTRIBUTION BY REGION,1800–2050

CURRENT WORLD POPULATION Top countries in World Population in 2011The most populated countries of the world.  Country Human Beings (in

millions)  

China 1,369India 1,270United States 321Indonesia 255Brazil 204 Pakistan 189Nigeria 183Bangladesh 158Russia 146Japan 126 Mexico 121Philippines 101Viet Nam (Vietnam) 91.5  

Ethiopia 90.0  

REGIONAL VARIATION WITH DEVELOPMENTAL STATUS

80-86%

20-14%

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

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.

DOUBLING TIME OF POPULATION IS APPROXIMATELY 14 YEARS.

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.

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.

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

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.

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_population5. http://www.prb.org/Educators/TeachersGuides/HumanPopulation/

PopulationGrowth.aspx

THANK YOU