1. Chapter 7
The Human Population

2. China is the world’s most populous nation and faces considerable environmental challenges
Population = 1.3 billion people
20% of the world’s population
China is experiencing rapid economic development
China may soon pass the US in consumption and pollution
Largest emitter of CO2 and SO2
Consumes 1/3 of commercial fish and seafood

3. Population growth rate of China

4. Graph of Predicted Population Growth and movement from rural to urban areas
Population growth and projection
Rural and urban populations

6. Carbon Dioxide Emissions from 1990-2030 in million metric tons

7. The Yangtze River before and after the three Gorges reservoir completely filled.
This is an image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite. It shows a 60 km stretch of the Yangtze River just west of the Three Gorges Dam. The upper image was acquired on May 20, 2001 before the dam was filled. The bottom image is from March 25, 2003, showing the partial filling of the reservoir.
When the Three Gorges reservoir will be completely filled in 2012, the lake will be some 600 km in length and submerge about 17,160 ha of farmland and some 200 ancient tombs.

8. China has taken steps to control its population growth.
1970- The one child policy goes into effect
Couple are rewarded financially for this. Those that have more children face sanctions.
Government uses abortions, sterilizations, and the designation of certain pregnancies as illegal.
These policies have significantly reduced population growth
If it continues at present rate, the Chinese population may begin to decline by 2040.

9. Chinese growing affluence creates greater use of resources
Number of vehicles= 25 million
By 2020, China will have 140 million vehicles
2nd largest consumer of petroleum
Higher fuel efficiency standards than the US
16/20 most polluted cities in the world were in China

10. Earth’s Carrying Capacity
The human population has grown more in the last 400 years than at any other time in history. During this time agricultural output and sanitation began to improve.
1798- Thomas Malthus English professor- hypothesized that as long as the human population was growing exponentially and the food supply was increasing linearly, eventually the population would exceed the food supply (reach carrying capacity and start to decline)

11. What do other scientists say?
A growing population means an increase in the supply of intellect that will lead to innovation and technological advances that will increase Earth’s carrying capacity.
Historical ex: the bow and arrow made hunting more efficient; increase crop yields by using oxen or horse driven plows.

12. Changes in population are studied by demographers
Inputs into a population includes births and and immigration
Outputs in populations includes deaths and emigration.
When inputs are greater than outputs, the population increases.
When outputs are greater than inputs, populations decline.

13. Let’s do the Math! .
Global population growth = [CBR-CDR] CBR = # of births/1000 ind
To calculate the population growth of a single nation we have to take immigration and emigration into account.
Nat. pop. = [(CBR + immigration)-(CDR + emigration)]
Growth rate
Rule of 70 (time to double a population)= 70
growth rate

14. Therefore a population growing at 2 percent a year will double in 35 years. 70/2= 35.

15. Why an increase in world population?
Some of the causes that resulted in rapid population growth are the development of science and technology, increase in food production and distribution, improvements in public health and disease conquest. The use of technology resulted in expansion of food production and distribution. Besides, the access to safe drinking water and the pressure to provide adequate housing led to progress in public health. Moreover, scientists have found ways to prevent and cure numerous diseases and reduced the death rate.  All this factors, altogether, have resulted in the increase of the world population.

16. Total Fertility Rate
Total Fertility Rate (TFR)= an estimate of the average # of children that each woman in a population will bear.
In the US it is 2.1
To gauge changes in population, demographers also calculate replacement level fertility, which is the TFR required to offset the the # of deaths in a population so that the current population size remains unchanged. Usually the number is 2 to replace the the parents who conceived them when those parents die.

17. Replacement-level Fertility
In developed countries the replacement fertility level is usually 2.1.
In developing countries, where mortality among the young tends to be higher, a TFR of greater than 2.1 is needed to achieve replacement –level fertility.
When TFR=RLF and immigration=emigration, a country’s population is stable.

18. Life Expectancy
The number of years that an infant born in a particular year in a particular country can be expected to live, given the current average life span and death rate in that country.
Can be reported for the overall population of a country or for males only and for females only.
Males have higher death rates than females
In the US avg. life expectancy is 75 for men, 81 for women.

19. Male Life Expectancy

20. Female Life Expectancy

21. Infant Mortality
Infant (death under 1 yr. of age) and child mortality (death under the age of 5)per 1000 live births.
There is a direct correlation between low infant and child mortality with high level of health care availability, food supply, potable water, sanitation and moderate levels of pollution.
Sometimes it is a result of socio-economic status.

22. Infant Mortality Rate World map

23. Disease According to the CDC, infectious disease is the
Is the second biggest killer worldwide after heart disease. Ex: HIV has already killed over 22 million people, most within the age range of 15-49, thus lowering life expectancy in those countries highly affected. (TB and Malaria as well).

24. A global view of HIV infection 39. 4 million people [range: 35. 9-44
A global view of HIV infection million people [range: million] living with HIV as of end 2004

25. Age Structure-describes how a populations age range is distributed, usually in 5 yr. increments.
Males
Females

26. Developing Countries population pyramid
Large number of infants with a young mortality rate still show a rapidly growing population.

27. China’s Population Pyramid 2005
China’s population control measure will eventually lead to a population decline.

28. Developed Countries population pyramid
Little difference between the number of individuals in younger groups and in older age groups. Little population growth. The US, Canada, Australia and Sweden look like thius.

29. Japan
Japan has an aging population, with few births to replace the population that is dying out.
Question for class: What does each diagram represent?

30. Migration
Net migration is the difference between immigration and emigration in a given year per 1000 people in a country.
Approx. 1million people immigrate to the US annually. Only a small number emigrate.
US population = 300million, so the net rate is 3.3 (will grow over next decade)
Canada= 7 and and TFR of 1.6(will grow over next decade)

31. Migration around the world
The movement of people around the world does not affect the total number of people on the planet.
But in does create many environmental issues:
Crowded conditions, unsanitary conditions, food and water shortages, refugee camps, deforestation, pollution, and disease

32. The theory of demographic transition
States that as a country moves from a subsistence economy to industrialization and increased affluence, it undergoes a predictable shift in population. There are 4 phases in the transition.
The country experience slow or no growth
Followed by rapid growth in phase 2
Population stabilization in phase 3
Population declines in phase 4

33. The Demographic Transition Model

34. Family Planning
As family income increases, people tend to have fewer children.
When females have higher levels of education and affluence, the lower the birth rates.
These same women have greater access to information about birth control.
Educated and working women have fewer children than other woman
A higher age at first reproduction means it is less likely to have more children
When women have the option to use family planning, crude birth rates drop.

35. In Developing countries:
A woman’s education is the single most important factor in determining how many children she bears and whether they survive.
EDUCATED WOMEN ... have fewer children
· In Brazil uneducated women give birth to 6.5 children. Those with secondary education bear only 2.5.
· In Liberia women secondary school graduates are ten times more likely to be using family planning than uneducated women.

36. UNICEF SAYS “WORLDWIDE
CHILDREN ... of educated women live longer
· Four to six years of mothers’ schooling reduces deaths of children in their first 12 months by as much as 20%. Every additional year of education causes a drop of up to 9% in deaths of children up to the age of six.
· A 1% rise in women’s literacy is three times more effective in reducing child mortality than a 1% rise in the number of doctors. “

37. Population size and consumption interact to influence the environment
Every human exacts a toll on the environment by eating, drinking, generating waste, and consuming products. All require energy, water, wood steel and other resources.
Since population and economic development are not equally distributed around the world, neither is the human impact on natural resources equally distributed.

38. Economic Development
Only 1.3billion/6.8billion humans live in developed countries.
9/12 populous nations are developing countries.
Populations in developed countries have leveled off while populations in developing countries have continued to grow rapidly.
One person in a developed country may have 2-10 x the environmental impact of a person in a developing country.

39. 7 Billion and Counting Video: 7 Billion and Counting
Global population trends result from varying levels of population growth and decline among countries. This informative video provides a simple and compelling overview of population trends that have created a world of 7 billion people.

40. 7 billion and counting video

41. Projected World Population Growth

42. World’s Ecological Footprint
The average ecological footprint for the world’s 30 wealthiest countries is 6.4 ha per capita.
The average ecological footprint for the 50 poorest countries is 1.0ha per capita
Calculating the per capita ecological footprint for a country provides a way to measure the affluence on the planet.

43. Footprints and affluence
The world’s average ecological footprint is 2.7ha (6.7 acres)per capita.
The US. = 9.0 (22 acres) per capita
China= 1.8 ha (4.5 acres) per capita
Haiti= 0.5ha (1.2 acres) per capita

44. The IPAT Equation Impact= Population x Affluence x Technology
Impact=overall environmental effect of a human population multiplied by affluence, multiplied by technology.
POPULATION= THE GREATER THE POPULATION THE GREATER THE IMPACT
AFFLUENCE= THE GREATER THE AFFLUENCE THE GRATER THE IMPACT
TECHNOLOGY = DESTRUCTIVE NOW ONLY

45. Local, Global, and Urban Impacts
Rural and agriculturally based societies usually have highly localized impacts
Affluent or urban societies tend to have global impacts du to more industrial production and high technology.
Most of China’s and the US ecological footprint come from using fossil fuels
In the Ivory Coast, small scale and subsistence agriculture leads to a footprint of 0.8ha per capita which comes from demand for food and fiber and woody biomass.

46. Local Impacts
Developing countries consume mainly locally produced material. This can lead to regional overuse of resources.
Land and woody biomass from trees and plants are highly consumed
Environmental impact= deforestation, soil erosion, soil degradation and habitat loss,
As well as water pollution from fertilizers.

47. Global Impacts on the Environment
Conversion of land to agriculture reduces the uptake of atmospheric CO2 by plants which affects the global carbon cycle.
Fertilizers made from fossil fuels, increases the release of greenhouse gases into the atmosphere.
People in suburban areas have a high consumption of imported energy sources such as oil, and foreign food imports, have lawns requiring fertilizers, pesticides, and water.
This group has the greatest impact of all lifestyles

48. Urban Impacts Urban areas= contain more than 386 people/km2.
Mumbai, India is the most densely populated urban area in the world=23,000 people/km2
NYC= 10, 400 people/ km2
More than 75% of people in developed countries live in urban areas, compared to 44% in developing countries

49. The 10 largest urban areas in the world
1 Tokyo  Japan 32,450,000 8,014 4,049
2 Seoul  South Korea 20,550,000 5,076 4,048
3 Mexico City[3]  Mexico 20,450,000 7,346 2,784
4 New York[4]  United States 19,750,000 17,884 1,104
5 Mumbai  India 19,200,000 2,350 8,170
6 Jakarta  Indonesia 18,900,000 5,100 3,706
7 São Paulo  Brazil 18,850,000 8,479 2,223
8 Delhi  India 18,600,000 3,182 5,845
9 Osaka-Kobe-Kyoto  Japan 17,375,000 6,930 2,507
10 Shanghai  China 16,650,000 5,177 3,216

50. World’s Largest Cities
Seoul
Tokyo
NYC
Mexico City

51. Urban Impacts
Urban areas produce greater amounts of solid waste, pollution and CO2 emissions than suburban and rural areas but have smaller ecological footprints. This is probably du to access to public transportation and many nearby services.
In developing countries, many of the poor urbanites live as squatters in shantytowns or slums

52. The impact of affluence
GDP or Gross Domestic Product= measure most commonly used to determine a nation’s wealth. It is the value of all products and services produced in a year. It is made up of 4 types of economic activity: consumer spending, investments, government spending, and exports minus imports.
As a country’s GDP increases, breathing dirty air poses a different risk to human health than poverty (due to burning coal during industrialization)
If GDP continues to increase, the nation can take measures to reduce its impact through its use of technology that counters pollution and increases efficiency of resources use.

53. Sustainable Development
Is sustainable economic development possible?
Can we improve the lives of others without further damaging the environment and exhausting our natural resources?
Human actions are depleting Earth’s natural capital. As a result the ability to sustain future generations can not be taken for granted.
Free Response questions on page 200 in text.