Transcript Earth Science and the Environment

World Regional Geography
Chapter 3:
Human Processes That
Shape World Regions
3.1 Two Revolutions That Changed the Earth
• The Agricultural Revolution
– Began in the Middle East about 10,000 years ago
• The Industrial Revolution
– Began in 18th Century Europe
3.1.1 Hunting and Gathering
• Our ancestors lived by foraging until 10,000 years ago
• Hunters & Gatherers stayed in small, family-based groups
• They were nomads, wandering from place to place to take
advantage of changing opportunities on the landscape
– Because of this movement, they had a relatively
limited impact on the natural environment
Rock Art from Egypt’s Sinai Peninsula
This artifact depicts Neolithic-period hunting of ibex, later uses
of camels and horses, and writing from the Nabatean period.
3.1.2 Revolutionary Aspects of Farming
• Domestication brought about the Agricultural Revolution
• Explanation for shift from hunt-and-gather to production?
– Change in Climate
– People compelled to find new food sources to support
growing populations
• Abandonment of nomadic lifestyles
– Shift from extensive land use to intensive land use
– People settled into small villages with fixed dwellings
• Irrigation along the Tigris, Euphrates, and Nile Rivers
– Bringing water to land artificially through levers and channels
– Raised carrying capacity and set stage for civilization
• Domesticated plants and animals proliferated at the
expense of wild species
Irrigation Along the Tigris River in Turkey
3.1.3 The Industrial Revolution
• Began in Europe around 1750 C.E.
• Based on technological breakthroughs made
possible by:
– Western Europe had economic capital necessary for
experimentation, innovation, and risk
– Significant improvements in agricultural productivity
took place in Europe prior to 1500
– Population Growth
• Greater number of people to devote their talents
and labor to experimentation and innovation
Tweed Mill in Stornoway, Scotland
3.1.4 Industrialization, Colonization
& Environmental Change
• Age of Discovery (Age of Exploration – 15th Cent.)
– As local supplies of resources needed for industrial
production were depleted, Europeans started to look abroad
• Exploration Resulted in Colonization
– European political and economic control over foreign areas
• Industrial Revolution’s Impact on Environment
– Since 1750, total forested area on earth has declined by
more than 20%
– Total cropland has grown by 500% during same period
– Human use of energy increased 100-fold since 1750
The Role of European Merchant Fleets
In the 18th century, European merchant fleets carried goods,
slaves, and information all around the world, profoundly
transforming cultures and natural environments
3.2 The Geography of Development
• Large disparity between wealthy and poor people
– Evident both within and between countries
• “Haves” vs. “Have-Nots”
– More Developed Countries
(MDCs)
– Less Developed Countries
(LDCs)
– Newly Industrializing Countries (NICs)
Wealth and Poverty By Country
Note the concentration of wealth in the
middle latitudes of the Northern Hemisphere
3.2.1 Measuring Development
• There is no universally accepted standard for
measuring wealth and poverty on the global scale
• However, these are some common indices:
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Gross Domestic Product (GDP)
Gross National Product (GNP)
Gross National Income (GNI)
Purchasing Power Parity (PPP)
Human Development Index (HDI)
3.2.2 Why Are Some Countries Rich & Others Poor?
• Dependency Theory
– Argues that the worldwide economic pattern established by both
the Industrial Revolution and colonialism persists today
• Advantageous & Disadvantageous Location
• Resource Wealth or Poverty
• Cultural and Historical Factors
3.2.3 Environmental Impacts of Underdevelopment
• LDCs have to borrow money from MDCs to fund development
– Many LDCs are unable to pay even the interest on these loans
– When lender institutions threaten to cut off assistance, borrowing
countries often try to raise money quickly using these methods:
• Dedication of high-quality land to production of cash crops,
which are exported to MDCs as luxury items
• Sale of Natural Assets
– Methods have a drastic long-term effect on the environment
• Humans using resources faster than nature can replace it
– Ecological Bankruptcy
• Occurs when countries exhaust their environmental capital
Thu Bon River in Vietnam
3.3 The Geography of Population
• Population may be the most critical issue in geography
– Number of people
– Rate at which people consume resources
• Human Population Explosion since 1800
– Will it lead to a crisis?
• Migration
– Spread of cultures, ideas, and opportunities
– Can spark tension and violence
3.3.1 How Many People Have Lived on Earth?
• Homo Sapiens ancestors
came out of Africa around
100,000 years ago to
populate Eurasia
• Population Explosion
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1 Billion in 1800
2 Billion in 1930
4 Billion in 1975
6 Billion in 1999
• Humans now are by far
the most populous large
mammal on earth
Global Human Population
3.3.2 How Can We Measure Population Changes?
• Birth Rate
– Annual number of live births per 1,000 people in a population
• Death Rate
– Annual number of deaths per 1,000 people in a population
• Population Change Rate
– Birth Rate minus the Death Rate
– May represent either growth or loss
3.3.3 What Determines Family Size?
• Better-educated and wealthier people, understanding the
economic cost of raising and educating a child, tend to
have fewer children
• Less educated and poorer people generally have more
children, sometimes to have additional workers to bring in
more family income
• People in cities tend to have fewer children than those in
rural areas
• Those who marry earlier tend to have more children
• Couples with access to and understanding of
contraception generally have fewer children
• Value systems and cultural norms play critical roles
3.3.4 What Determines Death Rates?
• Death rates correlate mainly with health factors
• Death rates can be reduced by:
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Better sanitation
Better hygiene
Cleaner drinking water
Availability of antibiotics and immunizations
Availability of insecticides
Improvements in medical and public health technologies
• Death rates rise with epidemics (HIV/AIDS, Black Death)
• Life Expectancy
– Number of years a person may expect to live in an environment
– United States Life Expectancy in 2007
• 80 years for Women
• 75 years for Men
Life Expectancy
3.3.5 The Rate of Population Change
• Rate of population change has been affected throughout
history by natural disasters, diseases, and wars
• With birth rates higher than death rates,
the trend has been one of growth
• Doubling Time
– Number of years required for the human population to double
– Computed by dividing 70 by the growth rate
– As of 2007, the global population change rate of 1.2%
means a doubling time of 58 years
Natural Rate of Population Change
Population change rates are highest in the countries
of Africa and other regions of the developing world
and lowest in the more affluent countries.
3.3.6 Why Has the Human Population “Exploded”?
• If the birth rate is high and the death rate is low,
the population surges
– This scenario has been occurring since around 1800
– This result has not been caused by a rise in birth rates,
but because the death rate has fallen
• Improvements in agricultural and medical technologies
• Demographic Transition Model
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Stage 1: Preindustrial
Stage 2: Transitional
Stage 3: Industrial
Stage 4: Postindustrial
Demographic Transition Model
Note how the population surged in the wake of the Industrial Revolution
as death rates fell while birth rates remained high but then leveled out
and began to decline as economic development advanced.
3.3.7 The Age Structure Diagram
• Population Pyramid
– Classifies a population by gender and by 5-year age increments
– Diagram Shapes
• LDCs are more bottom-heavy and pyramid-shaped
• MDCs are more chimney-shaped
• Population Under Age 15
– 31% of population of the poorer countries
– 17% of population of the wealthier countries
Age Structure Diagrams
A poor country, Niger has a relatively high birth
rate, with about 48% of the population under age
15. The United States’ population is growing
slowly, while Germany and some other
industrialized nations are losing populations.
LDCs vs. MDCs: Population by Age and Sex
3.3.8 Where Do We Live?
• The natural setting is the most important factor
• China and India are most populous countries
– China has a population of 1.3 billion
– India has a population of 1.1 billion
– 35% of people on earth in 2007 were Chinese or Indian
• United States ranks as 3rd most populated
– Migration the most important factor in increasing population
World Population Cartogram
The demographic heavyweights of China and India
stand out in the world population cartogram. The
United States and Indonesia, the world’s third and
fourth most populous countries, are prominent too.
World Regions by Land Area & Population
World Regions By
World Regions By
Land Area
Population
Population Density
3.3.9 Geography of Migration
• Migration refers to the movement of people
– Within a community, within a country or between countries
– Emigrant
One who moves FROM a place
– Immigrant
One who moves TO a place
• Migration is driven by Push and Pull Factors
– Examples of Push Factors
• When hunger or lack of land “pushes” people from rural areas
into cities, or when warfare or natural disasters push people
from one place to another
– Examples of Pull Factors
• Moving to a new area to take advantage of a job
or educational opportunity
Global Migration Trends
The global picture of people on the move. The major trends
are of migrants in search of work in more affluent countries
and of refugees driven by warfare or environmental adversity.
3.3.10 How Many People Will Live on Earth?
• Although it has been possible to calculate how many
people have lived on the earth in the past with some
confidence, projecting future numbers is difficult
– Will birth rates fall faster than anticipated in developing world?
– Will death rates surge due to disease or other epidemics?
• Predictions by the United Nations
– In 2050, the global population will be 9.2 billion
– The maximum number of people that will ever live on the
earth at one time will be 10.8 billion in 2150
Family Planning Billboard in Cairo, Egypt
This sign on the main square in Cairo, Egypt, urges parents to
have no more than two children “for the sake of a better life.”
UN Projections for World Population Growth
3.3.11 The Malthusian Scenario
• Thomas Malthus
– English clergyman who lived during Industrial Revolution
– He postulated that human populations, growing
geometrically or exponentially, would exceed food
supplies, which grow only arithmetically or linearly
– He predicted a catastrophic human die-off as a result of
this irreconcilable equation
• Neo-Malthusians vs. Technocentrists
– Neo-Malthusians insist that birth rates must be brought
down or humans will suffer nature’s solution, a
catastrophic increase in death rates
– Technocentrists are optimists who believe people
can raise the earth’s carrying capacity
Malthusian Scenario of People vs. Resources
Technocentric View of People vs. Resources
3.3.12 What Is “Overpopulation”?
• People Overpopulation
– Characteristic of the LDCs
– Many persons, with each using a small quantity of
natural resources daily to sustain life
• Consumption Overpopulation
– Characteristic of the MDCs
– Fewer persons, but each uses a large quantity of
natural resources from ecosystems around the world
Overpopulation Models: People & Consumption
3.4 Addressing Global Problems
• Death Rate Solution & Lifeboat Ethics
• Birth Rate Solution & Sustainable Development
3.4.1 Death Rate Solution & Lifeboat Ethics
• “Let nature take its course”
– Allow people imperiled by famine or other catastrophe to perish
• Lifeboat Ethics
– Introduced by ecologist Garrett Hardin
– Instead of seeing earth as a “global village” with a single carrying
capacity, views the world as a number of distinct “lifeboats,” each
occupied by the citizens of single countries
– Each wealthy nation is a lifeboat comfortably seating a few people
– Each poor nation is a lifeboat so overcrowded that many fall
overboard
– While the occupants of the rich lifeboats can choose to take on
the overboard refugees, Hardin suggests not, instead
preserving their own standard of living and ensuring the
world’s safety for themselves and their future generations
Lifeboat Ethics
3.4.2 Birth Rate Solution & Sustainable Development
• People must change their worldviews and value systems,
recognizing finiteness of resources and reducing their
expectations to a level sustainable by earth’s capabilities
• People should recognize that development and environmental
protection are compatible
• People should consider the needs of future generations more
• Communities and countries should strive for self-reliance,
particularly through the use of appropriate technologies
• LDCs need to limit population growth as a means of avoiding
the destructive impacts of people overpopulation
• Governments need to practice land reform, particularly in LDCs
• Economic growth in MDCs should be slowed to reduce
effects of consumption overpopulation
• Wealth should be redistributed between MDCs and LDCs