apes ch. 6
TRANSCRIPT
The Human Population and Its Impact
Ch. 6, part 1
Jot down the number of people in the world now
Our Growth Continues
Only in the last 200 years has it been going up so sharply
Question 1, with your pet buddy:
Hypothesize as to WHY our population growth continues to be so high
Why?3 main reasons
We’ve gotten better at living in more places
Agriculture meant we could feed more people
Better sanitation, medicines, and vaccines keeps disease under control
The results of all this
Death rate drops significantly
Birthrate has actually slowed - but it is not enough to counter the death rate
Some numbersThe global population is growing at ~ 1.2%/year
82 million people added to the population in 2008
Every second 5 people are born, 2 people die - a net gain of 3 people
That’s over 260,000 people per day
Where are all these people?We are not evenly spread out
Of the 82 million added in 20081.2 million added in the developed nations
80.8 million added in the developing nations
Developed vs. Developing Nations
DevelopedUSCanadaJapanAustraliaItalyEnglandFrance
Highly industrializedHigh GDP
DevelopingMost of AfricaMost of AsiaMost of Latin AmericaChinaIndiaBrazilTurkeyThailandMexico
Highly agriculturalLow GDP
What is the What is the difference difference between these between these two groups?two groups?
Developing nations
97% of the population growth from now to 2050 will occur in these countries
More than 1/2 the people in the world live in extreme poverty (less than $2/day; 17% of those on less than $1/day)
So how big are we going to get?
?
Projections are 8-11 billion by 2050
Question 2 with your holiday buddy: Vote!
Should the United States adopt a population control policy? Defend your position.
How many people can the Earth support?
Low estimates - 2 billion
High estimates - 30 billion
Is this even the right question to ask?
Another way of looking at it
Many analysts think we should be asking:
What is the optimum sustainable population based on a cultural carrying capacity
The optimum level at which most people can live in comfort and freedom without sacrificing that for future generations
Some basicsHigh births -- low deaths = high growth
Low births -- high deaths = decline
Equal births and deaths = stable population
3 rates control human population size
Birth rate
Death rate
Migration rate
We calculate the population change by subtracting those who leave (death, emigrants) from those who arrive (births, immigrants)
RatesWe don’t use raw numbers usually, we use RATES
Birth rate - the number of births per 1000 per year
Death rate - the number of death per 1000 per year
Who has the most people?Number 1: China at 1.5 billion
Number 2: India at 1.1 billion
Number 3: USA at 300 million
Number 4: Indonesia at 240 million
Number 5: Pakistan at 173 million
Together they have 36% of the people
Women are having fewer babies
Fertility rate - the number of children born to a woman during her lifetime
2 types1. Replacement level fertility rate - the
number of children a couple must have to replace themselves
1. 2.1 in developed nations
2. 2.5 in developing
2 types
2. Total fertility rate - the average number of children born to women in a population during their reproductive years
This has been going downDeveloped nations
1950 - 2.52008 - 1.6
Developing nations1950 - 6.52008 - 2.8
Question 3
WHY 2. WHY 2. something? Why something? Why not just 2?not just 2?
10 Factors that affect the birth rate
1. Children in the work force
1. Developing nations tend to have more children in the work force
More or less kids?More or less kids?
10 Factors that affect the birth rate2. The cost of raising and
educating children- birth rate lower in developed countries where it is much more expensive to raise kids (they don’t work for the family usually)
- costs about $290,000 to raise a kid to 18 years old
More or less kids?More or less kids?
10 Factors that affect the birth rate3. Private and public
pension systems (or lack thereof)
Pensions reduce the need for children to care for adults in their old age
More or less kids?More or less kids?
10 Factors that affect the birth rate
4. Urbanization - urban areas have more family planning clinics --> less kids
rural families need kids to help raise crops/livestock
More or less kids?More or less kids?
10 Factors that affect the birth rate
5. Education for women
fertility rate lower when women are educated
marriage is delayed also
More or less kids?More or less kids?
10 Factors that affect the birth rate6. Infant Mortality Rate
- the number of children per 1000 births who die before age 1
More or less kids?More or less kids?
10 Factors that affect the birth rate7. Age at marriage
More or less kids?More or less kids?
10 Factors that affect the birth rate8. Ability to have abortions
each year ~ 190 million pregnancies
~ 46 million abortions
(about half illegal) More or less kids?More or less kids?
10 Factors that affect the birth rate9. Availability of birth
control methods
More or less kids?More or less kids?
10 Factors that affect the birth rate10. Religious beliefs,
traditions, culture More or less kids?More or less kids?
Question 4
Is it rational for a poor couple in a developing country such as India to have 4 or 5 children?
Explain your thinking.
Put this number next to your name
Jot down the number of people in the world now
How many people were added during our lesson?