The Human Population

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Chapter 7

• The Human Population

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China is the worlds most populous nation and
faces considerable environmental challenges

• Population 1.3 billion people
• 20 of the worlds 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

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Population growth rate of China
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Graph of Predicted Population Growth and movement
from rural to urban areas
Population growth and projection
Rural and urban populations
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(No Transcript)
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Carbon Dioxide Emissions from 1990-2030 in
million metric tons
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The Yangtze River before and after the three
Gorges reservoir completely filled.
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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.

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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

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Earths 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)

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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
  Earths carrying capacity.
• Historical ex the bow and arrow made hunting
  more efficient increase crop yields by using
  oxen or horse driven plows.

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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.

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Lets do the Math!.

• Global population growth
  CBR-CDR CBR of births/1000
  ind. 10
• 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 10
• Rule of 70 (time to double a population) 70
• 
  growth rate

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

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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.

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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 TFRRLF and immigrationemigration, a
  countrys population is stable.

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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.

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Male Life Expectancy
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Female Life Expectancy
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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.

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Infant Mortality Rate World map
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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).

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A global view of HIV infection 39.4 million
people range 35.9-44.3 million living with HIV
as of end 2004
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Age Structure-describes how a populations age
range is distributed, usually in 5 yr.
increments.
Males
Females
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Developing Countries population pyramid
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Chinas Population Pyramid 2005
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Developed Countries population pyramid
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Japan
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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)

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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

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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

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• The Demographic Transition Model

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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.

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In Developing countries

• A womans 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.

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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 womens literacy is three times
  more effective in reducing child mortality than a
  1 rise in the number of doctors.

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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.

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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.

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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.

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7 billion and counting video
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Projected World Population Growth
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Worlds Ecological Footprint

• The average ecological footprint for the worlds
  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.

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Footprints and affluence

• The worlds 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

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The IPAT Equation

• Impact Population x Affluence x Technology
• Impactoverall 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

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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 Chinas 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.

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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.

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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

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Urban Impacts

• Urban areas contain more than 386 people/km2.
• Mumbai, India is the most densely populated urban
  area in the world23,000 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

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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 City3  Mexico 20,450,000 7,346 2,784
• 4 New York4  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

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Worlds Largest Cities
Seoul
Tokyo
NYC
Mexico City
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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

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The impact of affluence

• GDP or Gross Domestic Product measure most
  commonly used to determine a nations 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 countrys 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.

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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 Earths natural
  capital. As a result the ability to sustain
  future generations can not be taken for granted.