AP Environmental Science Ch. 6, part 1 - Human Populations

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Transcript of AP Environmental Science Ch. 6, part 1 - Human Populations

Today we will

• Begin Ch. 6 notesObjective:

Identify the reasons Identify the reasons why the human why the human population is still population is still growing exponentially growing exponentially and explain why those and explain why those things contribute to this things contribute to this growthgrowth

The Human Population and Its Impact

Ch. 6, part 1

Jot down the number of people in the world now

Our Growth ContinuesOnly in the

last 200 years has it been going up so sharply

Napkin DemoFold your napkin in half 4 timesHow thick would it be if you folded it in half 29 more times?3400 miles – distance from Boston to Germany

Question 1Hypothesize as to WHY our population growth continues to be so high

Why?3 main reasons

We’ve gotten better at living in more placesMore efficient agriculture means we can feed more peopleBetter sanitation, medicines, and vaccines keeps disease under control

The results of all thisDeath rate drops significantlyBirthrate has actually slowed - but it is not enough to counter the low death rate

Some numbersThe global population is growing at ~ 1.13% per yearAlready over 68 million people added this yearEvery second 5 people are born, 2 people die - a net gain of 3 peopleThat’s over 200,000 people per day, 140 people/minute

Where are all these people?We are not evenly spread outOf the 82 million added in 2008

1.2 million added in the developed nations80.8 million added in the developing nations

Developed vs. Developing Nations

DevelopedUSCanadaJapanAustraliaItalyEnglandFrance

Highly industrializedHigh GDP - Gross Domestic Product

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?

What information do you see in this chart?

List at least 3 specifics

Beans Demo

Close your eyesFirst – Americans – beans represent how much money the average American will spend in their entire lifeSecond – average global citizenThird – Average citizen of Malawi

Developing nations

97% of the population growth from now to 2050 will occur in these countriesMore 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

Vote!

Should the United States adopt a population control policy? Defend your position.

How many people can the Earth support?

Low estimates - 2 billionHigh estimates - 30 billionIs this even the right question to ask?

Another way of looking at itMany 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 basicsBirth rate higher than death rate = population growthBirth rate lower than death rate = declineEqual births and deaths = stable population

3 rates control human population size

Birth rateDeath rateMigration rateWe 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 RATESBirth rate - the number of births per 1000 per yearDeath rate - the number of deaths per 1000 per year

Who has the most people?Number 1: China at 1.4 billionNumber 2: India at 1.2 billionNumber 3: USA at 325 millionNumber 4: Indonesia at 250 millionNumber 5: Brazil at 200 millionNumber 6: Pakistan at 189 million

Together they have 36% of the people

Women are having fewer babiesFertility 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 nations2. 2.5 in developing

WHY WHY 2.something? Why 2.something? Why not just 2?not just 2?

2 types2. 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

10 Factors that affect the birth rate1. Children in the

work force1. 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 $300,000 to raise a kid to 18 years old in USA

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 rate4. Urbanization -

urban areas have more family planning clinics --> less kidsrural families need kids to help raise crops/livestock

More or less kids?More or less kids?

10 Factors that affect the birth rate5. Education for

womenfertility rate lower when women are educatedmarriage 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?

Is it rational for a poor couple in a developing country such as India to have 4 or 5 children?Explain your thinking.

It’s about the status of women in society

Lack of access to birth controlLack of access to safe abortionsLack of access to family planning clinicsYoung bridesLack of education for girlsHigh infant mortalityLow status of women in society

Jot down the number of people in the world now

How many people were added during our lesson?

The People Connection

Read the article and complete the worksheet as you doClass discussion to follow

The People Connection

Please have your green article and your white worksheet out on your desk

Citations from text to SUPPORT this statement

Statements Citations from text that REFUTE this

statement Population growth

continues to be so high because of high birth rates in countries all

over the world

As the years go on, the time it takes to double the size of the human

population gets shorter and shorter

There is plenty of land space to support every person on this planet

Because 98% of the population growth is

happening in developing nations, it does not

matter how many children an American family has

Directions

Please respond to the prompt with a statement like this:

“This idea is supported/refuted by this part of the text: ______________”Please also paraphrase what the last person said

Support/Refute this common statement

Population growth is still so high because people are having large families

Support/Refute this common statement

The time it takes to double the human population size is getting shorter and shorter

Support/Refute this common statement

There is plenty of land space for every person on this planet

Support/Refute this common statement

Because the vast majority of population growth is happening in developing nations, Americans don’t need to limit their family size

Why do we have environmental problems?

5 major reasons:Population growthWasteful and unsustainable resource usePovertyFailure to include the environmental cost of products in their pricesLack of knowledge about how the environment works

PovertyDefinition - when people are unable to meet their basic needs for food, water, shelter, health, and education

How poverty hurts the environment

Focus is daily survivalDesperate for resources, these people will degrade or deplete whatever is availableWorrying about the long term survival of an ecosystem is a luxury they cannot afford

Slum city in Mexico

Poverty hurts childrenOften trapped in an endless loop of povertyParents have many kids to help with

Gathering food, waterTending crops, livestockCaring for them in their old age

People in Poverty suffer the affects of pollution more acutely

Malnutrition - lack of protein and nutrients in diet

More likely to die from things like diarrhea and measlesOver 12,000 children under 5 die from diarrhea every day

Food for thoughtThis is equivalent to 60 fully loaded 200-passenger airliners crashing and killing everyone aboard, every day

"When one man dies it is a tragedy, but when a million people die it’s a statistic.”

Trayvon Martin Statistics?

People in poverty suffer the affects of pollution more acutelyNo sanitation systems for 38% of the world’s populationWater for drinking, bathing, cooking contaminated with human waste

Life-Straw - personal filtration system could save millions

Poor Man’s Gatorade Palm full of sugar and a pinch of salt

We CAN solve these problems - if we WANT to

Affluence hurts the environment, too

High levels of consumptionWasteful use of resourcesFueled by advertising making us think having more stuff will make us happyIt takes 27 trailers of resources per year for each American