““People are everywhere. Some people People are everywhere. Some people say there are too may of us; but no one say there are too may of us; but no one

wants to leave”wants to leave”

What is the Earth’s carrying capacity?

Present population is 7 billionMany believe the Earth can support 4-16

billion, others up to 50 billionChanges in technology, improvements in food

production and medicine plus the fact that humans can determine the number of children they have, make measuring the planet’s carrying capacity difficult

For most of our history, humans were hunter-gatherers, and these populations remained small.

About 10,000 years ago, people began to raise animals and grow crops. (Agricultural Revolution)

Agriculture allowed people to produce more food than they could gather, and to be able to store the excess. Farming increased the earth’s carrying capacity!

The human population then began to grow as more was available and people had more children to help with the farming.

The human population reached 1 billion around 1800.

Number of years to add 1 billion people

year years to addFirst billion 1800 all of human historySecond 1930 130Third 1960 30Fourth 1975 15Fifth 1987 12Sixth 1999 12Seventh 2012 13Eitgth 2026 14

DemographyThe study of human population patternsThere are 3 stages of demographic transition

Stage 1 reflects preindustrial societies in which the population grows slowly. Both birth and death rates are high

Stage 2 reflects an increasing population due to improved health care. Death rates fall and birth rates remain high. This is seen in developing countries such as Mexico, Bangladesh, and Ethiopia.

Stage 3 shows a slowing of population growth as birth rates fall. This is typical of a more developed country.

Population Pyramids (histograms) are one way to illustrate population growth.

Age structure categoriesPre-reproductive ages (0-14)Reproductive ages (15-44)Post-reproductive ages (45-over)

Males vs. females

We Can Use Age-Structure Information to Make Population and Economic Projections

Baby boomersJob market when they retire-job shortage

The Fastest Growing Age Group The Fastest Growing Age Group Is…Is…

SENIORS!SENIORS!The global populations of seniors is projected The global populations of seniors is projected

to triple by 2050 in which 1 of every 6 people to triple by 2050 in which 1 of every 6 people will be 65 or older.will be 65 or older.

This graying of the population is due to This graying of the population is due to declining birth rates and longer life declining birth rates and longer life expectancies due to medical advancementsexpectancies due to medical advancements.

The world’s population is increasing at a growth rate of 1.09%So, what does a 1.09% growth rate mean?

There were about 83 million people added to the earth in 2010

Which is about 227,000 people every dayWhich is 2 more people every time your heart

beats

Women Having Fewer Babies but Not Few Enough to Stabilize the World’s Population

Total fertility rate (TFR)- avg. # of kids born to a woman during reproductive years.

TFR in 2010:

1.7 per woman in developed countries

2.7 per woman in developing countries

Where are populations growing?in developing countries

their population is increasing 15 times faster than developed countries

By 2050, 97% of growth will be in developing countries

Growth Rates and TFRUS= 0.96% 2.0China= 0.49% 1.5Japan= -0.278% 1.2Mexico= 1.1% 2.3Ethiopia= 3.2% 6.0Zimbabwe = 4.31% 3.6Niger= 3.6% 7.6

From 1972- 2010, TFR in developing countries dropped from 6.2 to 2.7 and in developed countries, from 2.8 to 1.7

In China, the TFR dropped from 5.7 to 1.5 (from 1972-2010)

Life ExpectancyIncreased globally from 47 to 69 years Increased globally from 47 to 69 years

from 1955-2010. by 2050…74 yearsfrom 1955-2010. by 2050…74 yearsJapan has longest life expectancy of 83 Japan has longest life expectancy of 83

and US is 78 (50and US is 78 (50thth of all nations) of all nations)Angola has shortest life expectancy of Angola has shortest life expectancy of

39 years.39 years.

Why are people living longer?Why are people living longer?Increased food supply and distributionIncreased food supply and distributionBetter nutritionBetter nutritionMedical advancesMedical advancesImproved sanitationImproved sanitation

Why do growth rates increase?Immigration, decline in death rate, high TFRMost poor couples believe they need several

children to work and care for them in old ageCultural preference for male childrenOnly 48% use some form of birth control

Why Do Growth Rates Decrease?Emigration- religious and political freedom,

economic improvement, warsDeath and Disease- HIV/AIDSHigher education levels, medical care,

sanitation

Problems Related To Population Growth1. Shortage of resources

Water- diseases such as cholera, typhoid and dysentery and death related to dirty water

Fuelwood- many foods need to be cooked and water is sterilized by boiling

2. Urban Crisis

People move to cities for work and education

Not enough infrastructure- schools, medicine, fire stations, roads…

• 3. Social unrestCivil wars and disputes between nations

• 4. Environmental refugeesEnvironmental changes can cause people to leave their homesDrought, floods, earthquakes

Should population problems be solved?Countries with stable populations can better

provide services such as education and health care.

Environmental damage is decreasedFamilies are healthier when a mother bears

children after age 20, has no more than 3 children and they are spaced apart

Bangladesh- TFR dropped from 6.0 in 1960 to 2.7 in 2010.

Family planning and economic development are responsible for the drop.

Thailand’s TFR dropped from 6.4 to 1.8

The best way to slow and stabilize population growth are through1. promoting economic development2. elevating the social and economic status of women3. Encouraging family planning

Empowering Women Can Slow Population

EducationPaying jobsHuman rights without

suppression

“For poor women, the only holiday is when you are asleep”

Women account for 2/3 of all

hours worked, but only get 10%

of world's income

WomenMake up 70% of the world’s poor64% are illiterate (and 5-7

children)60-80% of work associated with

growing food, gathering wood and hauling wood and water

In most societies, they have fewer rights and educational and economic opportunities

(Sharbat Gula 1985 and 2002)(Afghanistan refugee who crossed

over into Pakistan

What is really the problem?Overpopulation? This is degrading our planet.

(82% of population is in less developed nations)

Overconsumption? Americans ecological footprints are 4.5X larger than the average Chinese and 9.5 times larger than the average Indian

If the world had 100 people…http://www.100people.org/statistics_detailed_

statistics.php?section=statistics