1. Population
1
MJ Rasaee
2015
1

2. Introduction
• The world population is
increasing, but not as rapidly as
it was a decade ago.
• In 1985 global population was
estimated at 4.84 billion, by
2002 it had reached 6.1 billion.
• In 2002 one-fifth of this total,
or 1.3 billion, lived in China,
with another billion living in
India.
• The US had 283 million
people(2001).
2
As the world’s population increases, so
does its use of resources.
The population problem, or crisis to some,
is not a recent phenomenon.
1798, the British economist Thomas
Malthus foresaw some of the world’s
current population problems.
He wrote the populations increase in size
geometrically. That is, they double in size
in a fixed time period.

3. Thomas Malthus (1798)
Arithmetic vs. geometric growth.
Population growth
Food production
3
He also wrote that
food supplies
increase
arithmetically;
Eventually, he
said, population
growth would
outstrip the food
resources, with
catastrophic
consequences—
mass starvation,
poverty, and
economic and
social collapse.

4. An 1817 Bolltun and Watt beam blowing
engine , used in Netherton at the iron works of
M W Grazebrook. Re-erected on the A38(M) in
Birmingham, UK
A steam Locomotive
from east Germany . This
class of engine was built
in 1942–1950 and
operated until 1988.
A typical preserved traction engine:
1910 Allohin 7 nhp agricultural
engine "Evedon Lad", at Stok
Goldinecton steam rally in 2005.
4
The history of population growth and food production since Malthus’time
has been very different from what Malthus predicted. Population has indeed
grown rapidly, but food production has grown even faster. Debates continue
today over the relationship between population growth, resource consumption
and scarcity, and environmental degradation.

5. • Neo-Malthusians take the same
perspective as Malthus, yet they argue
for strong birth control measures to
postpone or delay population growth to
a level below the limit of resource
availability.
5
A nineteenth-century critic of Malthus,
Karl Marx, stressed that there was no
single theory of population growth and
resource use.
Increased population growth did not by
itself result in excessive resource use and a
lowered standard of living.
Marx believed that poverty was caused by
the economic system.
In the twentieth century, Esther Boserup
and Julian Simon suggested that
population growth may be beneficial in
providing a stimulus for improving the
human condition.
Today some population experts
anticipate some form of population
catastrophe in the near future.
Others, however, are confident that
human needs can be met no matter
how large the world’s population
becomes.

6. Rank Country Area (Million
Hectares)
Biotech Crops
1 USA* 75.0 Maize, soybeans, cotton, canola, sugar beets,
alfalfa, papaya, squash, potatoes, apples
2 Brazil* 51.3 Soybeans, maize, cotton, sugarcane
3 Argentina* 23.9 Soybeans, maize, cotton
4 Canada* 12.7 Canola, maize, soybeans, sugar beets, alfalfa,
apples
5 India* 11.6 Cotton
6 Paraguay* 3.8 Soybeans, maize, cotton
7 China* 2.9 Cotton, Papaya
8 Pakistan* 2.8 Cotton
9 South Africa* 2.7 Maize, soybeans, cotton
10 Uruguay* 1.3 Soybeans, maize
11 Bolivia* 1.3 Soybeans
12 Australia* 0.8 Cotton, canola
13 Philippines* 0.6 Maize
14 Myanmar* 0.3 Cotton
15 Sudan* 0.2 Cotton
16 Mexico* 0.2 Cotton
17 Spain* 0.1 Maize
18 Colombia* 0.1 Cotton, maize
19 Vietnam <0.1 Maize
20 Honduras <0.1 Maize
21 Chile <0.1 Maize, soybeans, canola
22 Portugal <0.1 Maize
23 Bangladesh <0.1 Brinjal/Eggplant
24 Costa Rica <0.1 Cotton, soybeans
25 Indonesia <0.1 Sugarcane
26 eSwatini <0.1 Cotton
Total 191.7
*18 biotech mega-countries growing 50,000 hectares, or more, of biotech crops
**Rounded-off to the nearest hundred thousand.
Global Area of Biotech Crops in 2018: by Country (Million Hectares)**
6
For the past five years, developing countries have planted more biotech crops than the industrial countries (Figure 2).
In 2016, 19 developing countries planted 54% (99.6 million hectares) of the global biotech hectares, while 7 industrial
countries took the 46% (85.5 million hectares) share. This trend is expected to continue in the upcoming years due to
the increasing number of countries in the southern hemisphere adopting biotech crops and the commercialization of
new biotech crops such as rice, which is mostly grown in developing countries

7. Ran
k
Country 2015 2016
1 USA* 70.9 72.9
2 Brazil* 44.2 49.1
3 Argentin
a*
24.5 23.8
4 Canada* 11.0 11.6
5 India* 11.6 10.8
6 Paraguay
*
3.6 3.6
7 Pakistan
*
2.9 2.9
8 China* 3.7 2.8
9 South
Africa*
2.3 2.7
10 Uruguay
*
1.4 1.3
11 Bolivia* 1.1 1.2
12 Australia
*
0.7 0.9
13 Philippin
es*
0.7 0.8
14 Myanma
r*
0.3 0.3
15 Spain* 0.1 0.1
16 Sudan* 0.1 0.1
17 Mexico* 0.1 0.1
18 Colombi
a*
0.1 0.1
19 Vietnam <0.1 <0.1
20 Hondura
s
<0.1 <0.1
21 Chile <0.1 <0.1
22 Portugal <0.1 <0.1
23 Banglade
sh
<0.1 <0.1
24 Costa
Rica
<0.1 <0.1
25 Slovakia <0.1 <0.1
26 Czech
Republic
<0.1 <0.1
Total 181.5 179.7
Global Area of Biotech Crops in 2015 and 2016: by Country (million hectares)
7
Year Hectares
(Million)
Acres
(Million)
1996 1.7 4.3
1997 11.0 27.5
1998 27.8 69.5
1999 39.9 98.6
2000 44.2 109.2
2001 52.6 130.0
2002 58.7 145.0
2003 67.7 167.2
2004 81.0 200.0
2005 90.0 222.0
2006 102.0 250.0
2007 114.3 282.0
2008 125.0 308.8
2009 134.0 335.0
2010 148.0 365.0
2011 160.0 395.0
2012 170.3 420.8
2013 175.2 433.2
2014 181.5 448.0
2015 179.7 444.0
2016 185.1 457.4
Total 2,149.7 5,312.0
In 2016, the 21st year of
commercialization of biotech
crops, 185.1 million hectares of
biotech crops were planted by ~18
million farmers in 26 countries.
From the initial planting of 1.7
million hectares in 1996 when the
first biotech crop was
commercialized, the 185.1 million
hectares planted in 2016 indicates
~110-fold increase

8. The most planted biotech crops in 2016 were soybean, maize, cotton, and canola.
Although there was only 1% increase in the planting of biotech soybean, it
maintained its high adoption rate of 50% of the global biotech crops or 91.4 million
hectares. This area is 78% of the total soybean production worldwide
A significant increase of 13% was recorded for the global adoption rate
of biotech maize from 2015. Biotech maize occupied 60.6 million
hectares globally, which was 64% of the global maize production in
2016.Biotech cotton was planted to 22.3 million hectares in 2016,
which indicates a decrease by 7% from 2015. This reduction is
attributed to the low global cotton prices, which also affected the global
planting of non-biotech cotton. Biotech canola increased by 1% from
8.5 million hectares in 2015 to 8.6 million hectares in 2016. This raise
is attributed to the marginal increases in biotech canola plantings in the
USA, Canada, and Australia, addressing the demand for edible oil.
8
The Global Value of Biotech Crops
According to Cropnosis, the global market value of biotech
crops in 2016 was US$15.8 billion. This value indicates
that there was a 3% increase in the global market value of
biotech crops from 2015, which was US$15.3 billion. This
value represents 22% of the US$73.5 billion global crop
protection market in 2016, and 35% of the US$45 billion
global commercial seed market. The estimated global
farmgate revenues of the harvested commercial “end
product” (the biotech grain and other harvested products)
are more than ten times greater than the value of the
biotech seed alone.

9. Biotech crops increased ~113-fold from
1996 with accumulated biotech area at
2.5 billion hectares; thus, biotechnology is
the fastest adopted crop technology in the
world.
A total of 70 countries adopted
biotech crops – 26 countries
planted and 44 additional
countries imported.
9

10. A Brief History of Population Growth
• Although we cannot accurately measure
the world’s human population the distant
past, demographers and archaeologists,
among others, have developed low to
high ranges for population size and
growth over thousands of years.
10
The world’s human population at the end
of the most recent ice age, about 10,000
years ago, was somewhere between 2 and
10 million people. It had taken perhaps 1
to 2 million years for the population to
grow to this size.
From 8000 B.C. to A.D. 1 the population
doubled almost six times, to between 200
and 400 million.
Between A.D. 1 and 1750, growth
continued at about the same rate,
ultimately reaching 750 million by 1750.
It took only 150 years, from 1750 to 1900,
for the world’s population to double from
750 million to 1.5 billion.
The population doubled once again in 65
years between 1900 and 1965.
Nearly doubled again between 1965 and
2000, a mere 35 years.
Doubling time is the number of years it
takes a population to double in size,
assuming a constant rate of natural increase.

11. Doubling Time
• Definition: The amount of time for
a given population to double, based
on the annual growth rate. To
determine doubling time, divide the
growth rate as a percentage into 72.
i.e., a growth rate of 3.5 represents a
doubling time of 20 years.
• Afghanistan has a current growth
rate of 4.8%, representing a
doubling time of approximately 15
years (72/4.8=15). D/P .
• 72/1.2= 60 Year for Iran
11
In the mid-1960s, when the world’s
population was growing at 2.0 percent per
year, the doubling time of world
population was about 35 years.
By 2001, with a growth rate of 1.3 percent
per year, it had increased to about 47 year.
This change in doubling time shows the
weakness of the assumption of a constant
rate of increase.
Many factors have contributed to this dramatic increase in world population.
One is the development of a broader worldwide food base because of increased
trade
Another is humanity’s rise in overall disease resistance, which was also a result
of increased trade and travel.

12. • It has been suggested as well that population
began to rise in the wake of better medical
technology and theory, leading to a drop in
infant and child mortality rates and an
increased life span for large segments of the
world’s population such that at present there
are 1 billion old age population .
12
At the national and regional level, great differences in growth rates exist.
Some countries, notably in Africa and southwest Asia, have growth rate well
over 3% per year, with doubling times under 25 years.
Other areas, particularly Europe, have virtually zero population growth.

13. 13

14. Year Population
Yearly %
Change
Yearly
Change
Median
Age
Fertility
Rate
Density
(P/Km²)
Urban
Pop %
Urban
Population
2020 7,758,156,792 1.09 % 81,736,939 31 2.47 60 55.9 % 4,338,014,924
2025 8,141,661,007 0.97 % 76,700,843 32 2.43 63 57.8 % 4,705,773,576
2030 8,500,766,052 0.87 % 71,821,009 33 2.38 65 59.5 % 5,058,158,460
2035 8,838,907,877 0.78 % 67,628,365 34 2.35 68 61 % 5,394,234,712
2040 9,157,233,976 0.71 % 63,665,220 35 2.31 70 62.4 % 5,715,413,029
2045 9,453,891,780 0.64 % 59,331,561 35 2.28 73 63.8 % 6,030,924,065
2050 9,725,147,994 0.57 % 54,251,243 36 2.25 75 65.2 % 6,338,611,492
World Population Forecast
14

15. Birth, Death, and Fertility
• Natural growth is a simple measure of population growth that examine the
difference between births (fertility) and death (mortality) in a given group.
• Birth and death rates are normally expressed as rate of occurrence per 1000
people.
• Natural increase is the difference between birth and death rates and is
expressed as a percentage figure.
15
Birth, Death, and Fertility
Age Structure
Migration
Trends in Population Growth
Basic Demographics
The first includes the rate and causes of
population growth and is called population
dynamics.
The second is the location of growth, that
is, its spatial distribution around the world.
Two dimensions of the world population
picture

16. • Two factors are
important in
understanding global
population growth
1) rate of natural
growth/decline
2) the age structure of a
population.
3) A third factor,
immigration/emigratio
n, is an important
consideration at the
national or regional
level but does not
influence global trends.
In examining population dynamics, the first question
is: how and why do populations grow ??
16
One of the most important factors in
population growth today is the birth rate.
Birth rates are controlled mostly by the
fertility rate, a measure of the average
number of children a woman has in her
reproductive years (ages 15 to 49 years).
Birth rates are also affected by the age
structure of a population.
If there is a large number of young women
in a population, the birth rate will be
higher.

17. • Death rates are more closely
related to the age structure of
a population than are birth
rates.
• Countries with older
populations have higher
death rates than those with
younger populations.
• Death rates also affected by
factors such as nutrition and
the availability of health
care, and so high death rates
also occur in very poor
countries.
17
On a global scale, the total fertility rate
was 2.8 in 2001.
The rate is significantly higher in the less
industrialized nations (3.6) than in the
more industrialized nations (1.6).
Death rates in the world tend to be
between about 5% and 20% per thousand,
much lower than typical birth rates. This
difference between birth rates and death
rates results in population growth.

18. Trends in Population Growth and Fertility
Fertility has declined since the mid-
1960s, and population has been
growing at a decreasing rate over the
same time period.
18
One of the most important reasons for a
decline in the rate of natural growth in the
US has been a steady decrease in the
number of children born per family. This
is the same now for Iran which is
estimated to be 1.2 child per mother The
total fertility rate in the US has steadily
declined since the 1950s.
0
0.5
1
1.5
2
2.5
3
3.5
4
1950 1960 1970 1980 1990 2000
TFR
The US has seen significant variations in fertility in the last few decades.Right after World War II and into
the 1960s, the US fertility rate was at a modern-day high.The number of people under age 14 years has
decreased since 1970 because of lower reproducing rate.The median age in 1970 was 28 years .In 1980 it
was 30, by 1995 it was 34, and at the end of the century it was 35. Declining birth rates and the general
aging of the baby-boom cohort of the 1950s, coupled with a long life expectancy, account for this trend.

19. 19
For decades, debate has persisted on
the question of whether or not high
growth nations should work to
decrease their fertility rates.
China’s one-child limit for all
families.
For the past 25 years India has struggled to
reduce birth rates by providing various
economic and social incentives, as well as
by involuntary measures.
In some countries, fertility has declined
primarily as a result of government
sponsored family planning programs,
while in others the decline is attributed to
the increased educational and economic
levels of women.
Zero population growth (ZPG)
is a term indicating the number
of births that will simply replace
a population, without further
growth.
It takes a total fertility rate of
about 2.1 in developed nations
or 2.7 in developing nations to
maintain a population at a
constant size, assuming a stable
age structure and no net
migration.

20. 20
The second factor that contributes
to overall population change is the
age structure of a population.
The population pyramid (or more
correctly, the age-structure
diagram) is a visually striking
representation of the age and sex
structure of a population.
Demographers refer to age groups
(such as the population aged 5 to 9
years) as cohorts.
Age Structure
The difference is explained
by higher mortality rates in
the developing nations,
which require a higher
birth rate to offset losses.
A total fertility rate of less
than 2.1 would eventually
lead to population decline,
assuming no net
immigration.

21. Iran Population Pyramid
21
1995 1998 2000
2003 2005 2010

22. Demographic transition in Iran
22
Iran's population growth
rate dropped from an all-
time high of 3.2 percent in
1986 to just 1.2 percent in
2001, one of the fastest
drops ever recorded. In
reducing its population
growth to 1.2 percent, a
rate only slightly higher
than that of the United
States, Iran has emerged
as a model for other
countries that want to
accelerate the shift to
smaller families

23. Migration
• Migration, which includes immigration and
emigration, is the movement of individuals from
one location to another.
• It has no influence on global population
projections, but it does have a significant impact
at national, regional, and local population levels.
• Migration flows are caused by differences in
economic opportunities, group conflicts between
and within nations, and environmental
disruption. These flows can be permanent or
temporary.
• The populations of many
countries are affected by
migration.
23
In the long run, regions of high population
growth or poor economic conditions tend
to be areas of net emigration, while those
with strong economies and a need for labor
tend to be regions of net immigration.
Europe and North America have
substantial net immigration.

24. • As a result of increasing numbers of migrants
to the industrialized world, some countries
have devised restrictive policies for
immigration, maintaining that the immigrants
are stealing wages from native-born citizens.
• The situation is only a symptom of a larger
problem, that is, population pressure and
perceived lack of opportunity in many less
industrialized nations.
• Migration will continue as long as rural
populations in poorer countries perceive that
economic opportunity remains greater
elsewhere. 24

25. Trends in Population Growth
• How are rates of population growth
changing? Can present rates be extrapolated
into the future?
• The demographic transition is a widely used
generalization of past population change that
can be used to illustrate these processes.
25

26. Demographic Transition
The Demographic Transition Model describes growth in population as a
result of lag time between falling death rates and falling birth rates. 26

27. Demographic Transition Examples
27

28. ‫سال‬ ‫تا‬ ‫باروری‬ ‫دوران‬ ‫در‬ ‫زن‬ ‫هر‬ ‫به‬ ‫بچه‬ ‫تعداد‬ ‫متوسط‬
2050
28

29. The Distribution of Population and
Population Growth
• Regional Disparities
• Increasing Urbanization
29

30. • The world’s population is far from evenly
distributed.
• It is concentrated in five major regions of the
world: east Asia (especially China and
Japan), southeast Asia (Indonesia, Vietnam,
Myanmar), south Asia (India, Pakistan,
Bangladesh), Europe (European Union,
Russia), and eastern North America (US,
Canada).
30

31. 31

32. ‫سال‬ ‫در‬ ‫جمعیت‬
2050
‫از‬ ‫بیش‬ ،
50
%
‫در‬ ‫زمین‬ ‫افراد‬
‫داشت‬ ‫خواهند‬ ‫اقامت‬ ‫آسیا‬
32

33. Regional Disparities
• Currently, the most rapid population growth is
taking place in the less industrialized countries.
• Based on recent United Nations projections,
population worldwide will rise to 8.67 billion
by 2035, an increase of 2.96 billion.
• Only about 70 million of the 2.96 billion
increase will take place in more industrialized
countries;
33

34. • The other 2890 million, nearly 98% of the
projected growth, will occur in the less
industrialized countries.
• Between 1970 and 2000, fertility declined in
the industrialized nations brought fertility
levels to below replacement levels. In the less
industrialized nations, population continues to
grow because of both high fertility and
relatively young populations.
34

35. • While less industrialized countries
in 2001 represented about 80% of
the world’s population,
• in 2025 this portion will be about
84%,
• and it will reach 86% in 2050.
35

36. Increasing Urbanization
• Much of the world’s population growth since
the 1960s has occurred in urban places in
both industrialized and less industrialized
nations, and this trend is expected to
continue.
36

37. Major Metropolitan Areas of the World, 2001.
37

38. • It has intensified the pressures on usable
resources, including space, water, and food,
and it taxes national abilities to promote social
and economic welfare.
• This trend toward increasing urbanization is a
major problem facing the less industrialized
nations in the future.
• At present about half of the world’s population
live in urban areas.
38

39. • Since the 1960s, when the population problem
was recognized internationally, various
programs have been instituted to control
population, primarily through controlling
fertility.
• Some of these programs have been quite
coercive, such as forced sterilization or tax
penalties for large families.
• Others have focused on increasing
opportunities for women through education
and economic development.
39

40. Population Growth and Affluence
• Growths in population, affluence, and
technology are jointly responsible for
environmental degradation.
• While there is still some disagreement on the
strength of each individual component in
contributing to environmental decline, the
identity known as IPAT has endured for three
decades since it was initially proposed by Paul
Ehrlich and John Holdren.
40

41. IPAT
• IPAT is a simple formulation that states that
resource or environmental impact (I) equals
population (P) times affluence (A) times
technology (T).
• For our efforts toward a sustainable future, noted
geographer Robert Kates suggests a reformulation
of the original IPAT. I (resource depletion or
environmental impacts) equals P, or population
time C, or consumption per person, times the
impacts of that consumption.
41

42. • In order to achieve a sustainability,
• population growth needs to be slowed,
• consumers must be satisfied with what they have,
• and the individual impacts of consumption must
be shifted to less harmful patterns or reduced
through substitution.
42

43. Conclusion
• The rate of population growth worldwide is
clearly dropping.
• The reasons vary from one culture to another,
and in many cases the causes for declining
fertility are not clear.
• It is impossible to say whether population
control programs, industrialization, employment
opportunities for women, access to birth control,
or other factors are most responsible for the
change.
43

44. • Even though population growth is slowing, it
is still a major factor in the world resource
picture.
Conclusion
44