world population.ppt

7/27/2019 World Population.ppt

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. the presence of large numbers of human beings

is a relatively recent phenomenon.

For the vast bulk of human existenceupwardsof 95% people existed as hunters and

gatherers, collecting food from various wild

plants and stalking animals. This mode of production yields relatively few

calories per unit area and supports only low

population densities. Further, it is

demographically very stable over time: Because

births equaled deaths, there was virtually no

increase in the number of people in the world.


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. Following the agricultural revolution of roughly

8000 B.C., the capacity of many societies to

support more people increased somewhat. However, the really big gains in population did

not occur until the onset of the Industrial

Revolution of the eighteenth and nineteenthcenturies, when the transformation of

agriculture freed millions from lives of rural toil

and allowed for large, dense urban settlements.

Thus, exponential population growth is largely a

product of modernity and the modern world.


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. Today there are more than 7 billion people in the

world.

The diverse populations that inhabit the worldare very unevenly distributed geographically.Most people are concentrated in but few parts ofthe world, particularly along coastal areas and

the floodplains of major river systems. Four major areas of dense settlement are:

(1) East Asia, (2) South Asia, (3) Europe, and (4)

the eastern United States and Canada. In addition, there are minor clusters in Southeast

Asia, Africa, Latin America, and along the U.S.Pacific coast.


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. Asias population is the largest, as it has been for several

centuries.

In 2011, Asia contained 4.2 billion people, or 60% of the

worlds population. Six of the top 10 countries in population sizeChina,

India, Indonesia, Japan, Bangladesh, and Pakistanare inEast, South, or Southeast Asia, which, with 4.0 billionpeople, is home to 59% of the planets inhabitants.

Europe (including Russia) had 740 million residents, about11%;

other continents included Africa (1.07 billion, or 14%),Latin America (600 million, or 8.6%); North America (346million, or 5%), and Oceania (37 million, less than 1%).

The populations of the developing worldAfrica, Asia(excluding Japan), and Latin Americaaccounted for threeout of every four humans.


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. Ten out of the worlds nearly 200 countries account for

two-thirds of the worlds people.

Five countriesChina, India, the United States, Indonesia,and Brazil

contain half of the worlds population.

With 1.35 billion people, China is the worlds mostpopulous country. India, with 1.24 billion, is second, but isgrowing more quickly, and will surpass China inpopulation in roughly 30 years.

The United States, with 312 million in 2011, is third, and isby far the most populous of the developed nations.

Indonesia, the worlds largest Muslim nation, is fourth,with 240 million.

Only 3 of the 10 most populous nations are considered to be

economically developed (the United States, Russia, andJapan).


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Population Density

Because countries vary so greatly in size,

national population totals tell us nothing

about crowding.

Consequently, population is often related to

land area. This ratio is called population

densitythe average number of people per

unit area, usually per square mile or squarekilometer.


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. Several countries with the largest populations

have relatively

low population densities. For example, theUnited States is

the fourth most populous country, but in 2005 ithad a

population density of only 84 people per squaremile.

Although they have significant and dense

metropolitan areas, the United States and Canada form one of

the more

sparsely populated areas of the world.


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WORLD POPULATION DENSITY


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. Excluding countries with a very small area (e.g.,

Singapore), Bangladesh is the worlds most crowded

nation, where more than 148 million people are

crowded into an area the size of Iowa.

Three of the 10 most densely populated countries

the Netherlands, Japan, and Belgiumare

economically developed, whereas another threeSouth Korea, Taiwan, and Israelare newly

industrializing countries (NICs).

The remainder are clearly less developed nations,reminding us that there is no clear relationship

between population density and economic

development.


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. Contrary to popular opinion, not all crowded countries are

poor. In fact, in the Sahel states of Africa, populationdensities are very low.

But what explains the fact that many people in theNetherlands or Singapore live well on so little land?

Part of the explanation lies in their historical developmentand position within the colonial and contemporary world

systems. Part lies in their industrious people and theirability to adapt to change. Part lies in the policies of theirgovernments, which encourage economic growth.

And part of the explanation lies in their history of trade or

their relative locations. Singapore is on one of the greatocean crossroads of the world. But being on a crossroadshas worked no similar miracle for Panama. In 2008,Singapore had a per capita income ($29,700) that was fourtimes that of Panama ($7300).


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. National population densities are abstractions that

conceal much variation within countries as well asamong them.

Egypt had a reasonably low figure of 71 people persquare kilometer in 2005, but 96% of the populationlives on irrigated, cultivated land along the NileValley where densities are extremely high.

In China, the vast majority of people live in theeastern third of the country, near the Pacific Coast,where most of the large cities are concentrated.

Similarly, in the United States there are very densely

populated and sparsely populated areas. Large areasto the west of the Mississippi have few people,whereas the Northeast is densely settled. The islandof Manhattan, for example, has a density that isroughly the same as that of Hong Kong.


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FACTORS INFLUENCING POPULATION

DISTRIBUTION

One factor among many is the physical environment. Most of the worlds people tend to be concentrated along the

edges of continents, in river valleys, at low elevations, and inhumid midlatitude and subtropical climates.

Lands deficient in moisture, and hence inhospitable toagriculture (at least without widespread irrigation), such asthe Sahara Desert, are sparsely settled.

Few people live in very cold regions, such as northern

Canada, arctic Russia, and northern Scandinavia, wheregrowing seasons are short.

Many mountainous areaswhether because of climate, thinstony soils, or steep slopesare also low-density habitats.


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. Extreme caution must be exercised in ascribing

population distribution to the natural environmentalone.

To hold that climate or resources control populationdistribution is environmental determinism, a viewlong discredited because it is simplistic and oftenfactually incorrect.

Certainly climatic extremes, such as insufficientrainfall, present difficulties for human habitationand cultivation.

However, given the forces of technology, the

deficiencies of nature increasingly can be overcome.Air-conditioning, heating, water storage, andirrigation are examples of the extensive measuresthat technology offers to residents of otherwiseharsh environments.


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. If physical environments alone cannot explain the worlds

population distribution, what other factors are involved?

Human distributions are molded by the organization and

development of economic and political systems. It is thegeography of economic activitythe labor markets, jobopportunities, and infrastructures of urban areasthatgenerate large, dense populations in developed and,

increasingly, underdeveloped countries. Population sizes and distributions are influenced by the

demographic components of fertility, mortality, andmigration. Social disasters such as war or famine may alterpopulation distribution on any scale.

Policy decisions, such as tax policies or zoning andplanning ordinances, are eventually reflected on thepopulation map.


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. None of these factors, however, can be considered without

reference to historical circumstance. Present populationdistribution is explicable only in terms of the past.

Geographies are never created instantaneously, and the

location of the worlds people is the accumulation of forcesoperating at the global, national, and local scales for centuriesor longer.

For example, the high population densities of Europe or thenortheastern United States reflect the accumulated impacts of

the Industrial Revolution and its associated waves ofurbanization.

Chinas large population was centuries in the making,reflecting long periods of fertile agriculture, irrigation, and asocial system stretched over vast areas.

The distribution of people in the developing world is largely areflection of the centuries of colonialism, which focusedgrowth on coastal areas, the locations of the port cities thatwere the centers of maritime trade in the colonial worldeconomy.


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POPULATION GROWTH OVER TIME

AND SPACE The geography of the worlds population is never static but

is in constant change. The worlds population is increasing,albeit at a decreasing rate.

Each year an additional 76 million people inhabit the earth,which means the planet adds 208,000 people daily, about2.4 per second.

Many countries in Europe, Russia, and Japan, are losingpopulation as their deaths exceed births. The major locusof world population growth is in the developing countries,in which more than three-fourths of humankind dwells.

With 6.9 billion people already and another billionexpected by the year 2015, how will the developing worldmanage?


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Population Change

The current rapid growth rate of the worldpopulation is a recent phenomenon.

It took from the emergence of humankind until1850 for the world population to reach 1 billion.

The second billion was added in 80 years 64 TheWorld Economy: Geography, Business,Development (18501930), the third billion wasadded in 30 years (19311960), the fourth in 16

years (19601976), the fifth in only 11 years(19771987), and the sixth in 12 years (19871999).

The ast b lk of the orlds pop lation gro th is occ rring in


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The vast bulk of the worlds population growth is occurring inthe developing world. Of the continents, Africa has the fastestrate of growth.

In 2008, the population of Africa was growing by 2.4% peryear. Malawi, with a population growth rate of 3.2% per year,the highest in the world, will see its population double in just22 years.

Rapidly declining death rates and continued high birth rates

are the cause of this explosion. Death rates have been fallingto fewer than 10 deaths per 1000 people each year in Asiaand Latin America, and to about 13 per 1000 in Africa.

Crude birth rates are changing less spectacularly. They are

highest in Africa (37 births per 1000 people annually), LatinAmerica (21 per 1000), and Asia (19 per 1000).

These latter figures compare with crude birth rates of 11 per1000 in Europe and 14 per 1000 in North America.

Th ld l i 6 9 billi i 2010 d


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. The world population was 6.9 billion in 2010, and

the United Nations projects it will reach 9 billion in

2050.

Almost all of this increase will occur in the

developing countries.

The largest absolute increase is projected for Asia,

reflecting its huge population base.

Future population growth will further accentuate

the uneven distribution of the worlds population.

In 2010, 80% of the worlds population lived in the

developing world, but by the year 2050, the

proportion will increase to 90%.


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The rate of natural increase for a country or a region ismeasured as the difference between the birth rate andthe death rate.

Births and deaths represent two of the three basic

population change processes; the third is migration. Every population combines these three processes to

generate its pattern of growth.

We can express the relationship among them using theequation:

Population change = Births Deaths + In-migration -Out-migration, or,

P = BR - DR + I - O,

where CP represents the rate of population change BR is the


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where CP represents the rate of population change, BR is thecrude birth rate, DR is the crude death rate, I is the totalin-migration rate (immigration, if internationally), and O is thetotal out-migration rate (or emigration, if internationally).

The natural growth rate (NGR)

the most importantcomponent of population change in most societiesisdefined as the difference between the birth and death rates:

NGR = BR - DR

while net migration rates (NMR) are the difference betweenin-migration and out-migration rates:

NMR = I - O.

Thus, P = NGR + NMR,

where NGR is the natural growth rate and NMR is the netmigration rate.

F th ld h l t i ti i b i l


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. For the world as a whole, net migration is obviously

zero. However, for any scale smaller than the globe,

both

natural growth and net migration must be included.

Natural increase accounts for the greatest

population

growth in most societies, especially in the short run.

However, in the long run, migration contributes

significantly because the children of immigrants add to the

population base.

world population.ppt

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