6- 1

© 2010 Pearson Education Canada

6Human Population

PowerPoint® Slides prepared by Stephen Turnbull

Copyright © 2013 Pearson Canada Inc.6-1


Copyright © 2013 Pearson Canada Inc.

Housekeeping Items• I have a few more replacement course outlines for those

who weren’t here on Wednesday.• Any questions about the assignment instructions on the

web site?• Anyone want to volunteer an answer to the question I

sent out in the aftermath of our watching most of Home?• To reiterate, given the innumerable institutional and

psychological obstacles to societies and individuals changing course, what are some hopeful examples of positive change and what seem to be the most effective strategies for effecting changing?



POPULATION ISSUES: Upon successfully completing this chapter, you will be able to

• Assess the scope and historical patterns of human population growth

• Evaluate how human population, affluence and technology affect the environment

• Explain and apply the fundamental concepts of demography

• Outline the concept of demographic transition• Describe how wealth and poverty, the status of women, and

family planning affect population growth• Link population goals to sustainable development

6-3



Central Case: China’s one-child policy

• In 1979, the government instituted a one-child policy, drastically decreasing the growth rate (now 0.5%)

• Unintended consequences: - Killing female infants - Unbalanced sex ratio- Black-market trade in teenage girls

“As you improve health in a society, population growth goes down. You know. I thought it was…before I learned about it, I thought it was paradoxical.”

– Bill Gates, Microsoft Corp.

6-4



The Human Population at 7 Billion (and growing at 220,000 a day!)

6-5



Human population: at 7 billion

• Populations continue to rise in most countries- Particularly in developing nations

• Although the rate of growth is slowing, we are still increasing in absolute numbers

• How much is 7 billion?- It would take 30 years, counting once each

second, to reach 1 billion

6-6



The human population is growing nearly as fast as ever

• It took all of human history- after 1880 - to reach 1 billion

• In 1927 we reached 2 billion, and added the most recent billion in 12 years

6-7



The human population is growing nearly as fast as ever (cont’d)

• At today’s 2.1% annual growth rate, the population will double in 33 years

• If China’s rate had continued at 2.8%, it would have had 2 billion people in 2004.

6-8



Perspectives on human population have changed over time

• 1700s – more children meant more hands for agriculture, better support in old age and more labour for factory work

• 1766: Thomas Malthus – growing population is eventually checked by limits on births or increases in deaths

• 1968: Paul Ehrlich – population is growing too fast and must be controlled- Disastrous effects on the environment and

human welfare

6-9



Perspectives on human population have changed over time (cont’d)

• Ehrlich and other neo-Malthusians have argued that population is growing much faster than our ability to produce and distribute food and that population control is the only way to prevent:

- Massive starvation

- Environmental degradation

- Civil strife

6-10



Is population growth really a “problem” today?

• Population growth results from technology, sanitation, food- Death rates drop, but not birth rates

• Some people say growth is no problem- New resources will replace depleted ones- But, some resources (i.e., biodiversity) are

irreplaceable• Quality of life will suffer with unchecked growth

- Less food, space, wealth per person

6-11



Is population growth really a “problem” today (cont’d)?

• Sheldon Richman – humans find potential stuff and human intelligence turns it into resources

• Humankind will always be able to save itself with a “technological fix”

• Yet not all resources can be replaced or reinvented once they are depleted (e.g. extinct species, land)

• Population growth is much more strongly correlated with poverty than with wealth

6-12



Is population growth really a “problem” today (cont’d)?

• Policymakers believe growth increases economic, political, military strength- They offer incentives for more children- 49% of European nations think their birth rates

are too low (examples of other countries or jurisdictions who feel the same way?)

- In non-European nations, only 12% feel their birth rates are too low

6-13



The Science Behind the Story• Mapping Our Population’s Environmental Impact

- Burgeoning numbers of people are making heavy demands on Earth’s natural resources and ecosystem services

- Humans are responsible for using up almost 24% (some say 40%) of the planet’s NPP – that’s one species out of 1.4 million known species and probably million total species

- Direct harvesting of crops, timber, etc. account for most of this

- Densely populated and heavily farmed regions such as India, Eastern China, and Europe show the greatest proportional use of NPP

6-14



Population is one of several factors that affect the environment

• The IPAT model: I = P x A x T x S- Our total impact (I) on the environment results

from the interaction of population (P), affluence (A) and technology (T), with an added sensitivity (S) factor

- Population = individuals need space and resources- Affluence = greater per capita resource use- Technology = increased exploitation of resources- Sensitivity = how sensitive an area is to human

pressure

6-15



Population is one of several factors that affect the environment (cont’d)• Status quo leads to

- Sudden food & population decrease

- Pollution increase

• Sustainability leads to- Food & population

stabilizing- Pollution decrease

6-16



Demography

6-17

• “Soft” vs. “crash” landing• Agribusiness companies like Monsanto use food/

population crunch as rationale for GMOs, etc.



The environment has a carrying capacity for humans, as with all species• Demography: the application of population ecology

principles to the study of statistical change in human populations

• Environmental factors set limits on our population growth, and the environment has a carrying capacity for our species

• Four significant periods of societal change appear to have fundamentally altered the human relationship with the environment

6-18



The environment has a carrying capacity for humans (cont’d)

• Paleolithic period (Old Stone Age): - Use of fire as long as 1.5 million years ago- Shape and use of stones 2.5 million years ago, which

helped proto-humans modify their environment- Little evidence about world populations at that time,

but likely in the hundreds of thousands/ million or so at most

6-19

FIGURE 6.7




• Neolithic (New Stone Age):- Agricultural Revolution- 10,000 to 12,000 years ago- Initiated a permanent change in the way humans relate

to the natural environment- Made cities, trades, science, armies, and other aspects

of modern culture possible

6-20

FIGURE 6.7




• Industrial Revolution:- Began in the mid – 1700s- A shift from rural life, animal-powered agriculture,

and manufacturing by craftsmen, to an urban society powered by fossil fuels

- Improvements in sanitation and medical technology- Enhanced agricultural production

6-21

FIGURE 6.7




• Medical-Technological Revolution:- Currently in the midst of modern medical and

technological advancements- People live longer and healthier lives- Green Revolution – shift to modern agricultural

practices, but with environmental consequences

6-22

FIGURE 6.7



Demography is the study of human population• Demographers study:

- Population size- Density- Distribution- Age structure- Sex ratio- Rates of birth, death, immigration, and emigration

6-23



Demography is the study of human population (cont’d)• Population size - only one factor and does not tell the

whole story• A population’s environmental impact depends on its

density, distribution, and composition, as well as affluence, technology, and level of consumption

6-24



Demography is the study of human population (cont’d)

• Humans are unevenly distributed around the globe• Highest population density is in temperate,

subtropical, and tropical climates (any exceptions?)- Unpopulated areas tend to be environmentally

sensitive (high S value in the IPAT equation)

6-25



Demography is the study of human population (cont’d)• Age structure important in predicting future

dynamics of populations• Having many individuals in young age groups

results in high reproduction and rapid population growth

6-26



China’s reproductive policy

Consider the benefits as well as the problems associated with a reproductive policy such as China’s.

•Should a government be able to enforce strict penalties for citizens who fail to abide by such a policy? •What alternatives can you suggest for dealing with the resource demands of a quickly growing population?• (What) is there a balance point between public interest and individual choice?

weighing

the issues

6-27



Demography is the study of human population (cont’d)• Sex Ratios can affect population dynamics• Naturally occurring sex ratios for humans slightly

favour males (100 females born to 106 males)• In China, 120 boys were reported for 100 girls

- Cultural gender preferences, combined with the government’s one-child policy, led to selective abortion of female fetuses

- Had the undesirable social consequences of many single Chinese men

- Teenage girls were kidnapped and sold as brides

6-28



Population change results from birth, death, immigration, and emigration

• Whether a population grows, shrinks, or remains stable depends on:- Rates of birth, death, and migration- Birth and immigration add individuals- Death and emigration remove individuals

• Crude birth rate (nativity or natality) = number of births per 1000 individuals

• Crude death rate (mortality) = number of deaths per 1000 individuals

6-29




• Technological advances led to dramatic decline in human death rates widening the gap between crude birth rates and crude death rates and resulting in population expansion

• Growth rates in many countries have been declining, even without population control policies- Decline due in part from a steep drop in birth

rates

6-30



Total fertility rate influences population growth

• Total fertility rate (TFR) = average number of children born per female member of a population during her lifetime

• Replacement fertility = the TFR that keeps the size of a population stable

6-32



Total fertility rate influences population growth (cont’d)

• Increasing urbanization decreases TFR- Children go to school, and increase costs

• With social security, elderly parents need fewer children to support them

• Greater education allows women to enter the labor force, with less emphasis on child rearing

6-33



Consequences of low fertility?

In Canada, the United States, and every European nation, the total fertility rate has now dipped below replacement fertility rate.

• What economic, social, or environmental consequences – positive or negative – do you think might result from below-replacement fertility rates?

weighing

the issues

6-34



Some nations have experienced the demographic transition• Natural rate of population change = due to birth

and death rates alone- In countries with good sanitation, health care,

and food, people live longer• Life expectancy = average number of years that

an individual is likely to continue to live- Increased due to reduced rates of infant

mortality- Urbanization, industrialization, and personal

wealth

6-35



Some nations have experienced the demographic transition (cont’d)

• Demographic transition = a model of economic and cultural change to explain the declining death and birth rates in industrializing nations

• high birth and death rates change to low birth and death rates

• As mortality decreases, there is less need for large families- Parents invest in quality of life

6-36



Some nations have experienced the demographic transition (cont’d)

Population growth is seen as a temporary phenomenon6-37



Is the demographic transition a universal process?• It has occurred in Europe, U.S., Canada, Japan,

and other nations over the past 200-300 years• But, it may or may not apply to all developing

nations• The transition could fail in cultures that

- place greater value on childbirth- grant women fewer freedoms

For people to attain the material standard of living of North Americans, we would need the natural resources of four and a half more Earths

6-38



Population and Society

6-39



The status of women greatly affects population growth rates• 2010: 55% of married women (aged 15-49)

worldwide reported using modern contraception to plan / prevent pregnancy

• Social empowerment of women reduces unintended pregnancy

• Increasing female literacy, not to mention increased employment, is strongly associated with reduced birth rates

6-40



Increasing female literacy is strongly associated with reduced birth rates in many nations

6-41

The status of women greatly affects population growth rates (cont’d)



Population policies and family-planning programs are working

• These policies lower population growth rates in all types of nations

• Programs for population control:- India – incentives for a “two-child norm”- Thailand – family planning education and increased

availability of contraceptives• 1994: U.N. platform for governments to offer universal

access to reproductive health care within 20 years. During its chairmanship of the G8, Canada introduced a policy but refused to include a family planning component.

6-42



Current state of women’s reproductive health• According to research accessed by the Canadian Labour

Congress• Approximately 215 million women who want to avoid pregnancy

are not able to access an effective method of modern contraception;• Only one-half of the 123 million women who give birth each year

receive antenatal, delivery and newborn care from a doctor or midwife, or do not receive all components of the care they need;

• Over half a million women, including adolescent girls, die due to complications during pregnancy and childbirth every year;

• Approximately 20 million women have unsafe abortions each year. Three million women who experience complications caused by unsafe abortions do not receive medical attention. Approximately 68,000 women die each year due to unsafe abortions.



Population policies and family-planning programs are working (cont’d)

Blue = family planning accessible

Red = family planning not accessible

6-44



• Poorer societies have higher growth rates than wealthier societies- Consistent with the demographic transition theory- They have higher fertility and growth rates, with lower

contraceptive use• 99% of the next billion people added will be born in poor, less

developed regions that are least able to support them• Poverty often results in environmental degradation (e.g. soil

degradation, hunting of large mammals)• While wealthier societies have a much bigger eco-footprint

overall, poverty is not without its effects. Why?

Poverty is strongly correlated with population growth

6-45



Consumption from affluence creates environmental impacts

• Affluent societies have enormous resource consumption and waste production- People use resources from other areas, as well as

from their own- Individuals’ ecological footprints are huge

• The addition of 1 Canadian to the world has as much environmental impact as 6 Chinese, or 12 Indians or Ethiopians, or 40 Somalians.

6-46



Consumption from affluence creates environmental impacts (cont’d)

Humanity’s global ecological footprint

surpassed Earth’s capacity to

support us in 1987

6-47



The wealth gap and population growth contribute to conflict• The richest 20% use 86%

of the world’s resources• Which leaves 14% of the

resources for 80% of the world’s people to share

6-48

Source: Bing



HIV/AIDS impacts African populations• 2008: 33 million infected

worldwide, two-thirds live in sub-Saharan Africa

• Low rates of contraceptive use spread the disease

• Also spreading in Caribbean, Southeast Asia, eastern Europe, central Asia

• 14 million children havelost one or both parents

• Until recently, the Catholic Church forbade Africans to use condoms despite the HIV epidemic

• Grandmothers’ initiative

6-49



Demographic change has social, economic, and environmental repercussions

• Demographic fatigue = governments face overwhelming challenges related to population growth. - With the added of stress of HIV/AIDS;

governments are stretched beyond their capabilities

- Economies lose potentially productive workers who instead become a burden on their families

- Problems grow worse

6-50



The U.N. has articulated sustainable development goals for humanity• Millennium Development Goals = by 2015 achieve goals

for sustainable development - Does not include population control (any ideas why?)

• Earth does not hold enough resources to sustain 7 billion of us at the North American standard of living

6-51



Conclusion• The human population is larger than at any time in the past

(more people alive today than all the humans who have ever existed put together)

• Growing population as well as growing consumption, affects the environment

• Growth rate has decreased nearly everywhere• Progress has been made in expanding rights for women

worldwide• How will the population stop rising?

- Demographic transitions- Governmental intervention- Disease - Social conflict

6-52



QUESTION: Review

What has accounted for the majority of the world’s population growth in recent years?

a) Women are having more babiesb) Death rates have dropped due to technology,

medicine, and foodc) More women are using contraceptivesd) Nothing, the population has dropped in recent

years

6-53



QUESTION: ReviewAccording to the I = P x A x T formula, what would happen if China’s 1 billion people had a lifestyle like Canadians?

a) Their population would automatically dropb) Their population would automatically increasec) Their affluence and technology would increased) Their impact on the environment would even

out

6-54



QUESTION: Review

How have humans been able to raise the environment’s carrying capacity for our species?

a) Through technologyb) By eliminating limiting factorsc) Through increased consumptiond) Spending more money on non-essential resources

6-55



QUESTION: Review

Areas that lack significant numbers of people, and have a low population density are…

a) No longer availableb) Best able to support higher densities of peoplec) Sensitive areas least able to support high densities

of peopled) Located around tropical and grassland areas

6-56



QUESTION: Review

Describe the relationship between growth rates and population size.

a) Falling growth rates automatically mean a smaller population

b) Falling growth rates automatically mean a larger population

c) Falling growth rates means we no longer have a population problem

d) Falling growth rates does not mean a smaller population, but that rates of increase are slowing

6-57



QUESTION: Interpreting Graphs and Data

a) High birth and death rates rise cause population increasesb) High birth and death rates, but population is stablec) High birth rates with low death rates cause population to

increased) Low birth and death rates cause the population to decrease

What happens during the “pre-industrial” stage of the demographic transition?

6-58



QUESTION: Interpreting Graphs and DataAccording to this age pyramid, Madagascar’s future population will be…?

a) Balancedb) Largerc) Much largerd) Smallere) Much smaller

6-59



QUESTION: Interpreting Graphs and Data

6-60

a) Iraq and Pakistanb) Malawi and Haitic) Malawi and Kenyad) Kenya and Bangladesh

According to these graphs, which countries had access to family planning?

6- 1

Documents

Transcript of 6- 1