Transcript Living in the environment

A Global Concern
Chapter Overview Questions
• What are the main themes of this book?
• What keeps us alive? What is an
environmentally sustainable society?
• How fast is the human population growing?
• What is the difference between economic
growth, economic development, and
environmentally sustainable economic
development?
Chapter Overview Questions
(cont’d)
• What are the harmful environmental effects
of poverty and affluence? (Is affluence a
bad thing?)
• What three major human cultural changes
have taken place since humans arrived?
• What are the four scientific principles of
sustainability and how can we use them to
build more environmentally sustainable
societies during this century?
What is Environmental Science?
• The goals of environmental science are to
learn:
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how nature works.
how the environment affects us.
how we affect the environment.
how we can live more sustainably without
degrading our life-support system.
Environmental Science
• Interdisciplinary science –ecology,
geology, chemistry,
• Politics, engineering, economics, ethics
• Connections and interactions between
humans and the rest of nature
• Validity of data questioned – many
variables
Environmental Issues
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Population growth
Increasing resource use
Destruction and degradation of habitat
Premature extinction
Poverty
Pollution
Carrying Capacity
• The total number of organisms an environment
can support over a specified period
• Some factors that regulate populations include:
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Predation
Amount of resources (food, space)
Natural disasters- hurricane, volcano eruption, etc.
Disease
Sustainability: The Integrative Theme
• Sustainability is the ability of earth’s various
systems to survive and adapt to environmental
conditions indefinitely.
• The steps to sustainability must be supported by
sound science.
Figure 1-3
Population Growth
Linear Growth
• Quantity increases
by a constant amount
per unit of time
• 1,2,3,4,5, …
• 1,3,5,7,9, …
• When plotted on a
graph, S shaped curve
appears
120
100
80
60
40
20
0
1960
1980
2000
2020
Population Growth
2. Exponential Growth
Population Growth
• Starts off slowly, doubles
a few times, then grows
rapidly.
• J shaped curve
3000
• Current human
population: ~ 6.86 billion
1000
• 1.2% growth increase/year
2500
2000
1500
500
0
1970 1980 1990 2000 2010 2020
Core Case Study:
Living in an Exponential Age
• Human population growth: J-shaped curve
Figure 1-1
Doubling Time
• Rule of 70:
– Doubling time is equal to:
70 / the growth rate %
• Example:
If a country had a population of 100 people
and a growth rate of 7%. How long would it
take for them to double their population?
70 / 7% = 10 years
Population Growth, Economic Growth, and
Economic Development
• Economic growth provides people with more
goods and services.
– Measured in gross domestic product (GDP)
– Economic development uses economic growth to
improve living standards.
– The world’s countries economic status (developed vs.
developing) are based on their degree of
industrialization and GDP.
Global Outlook
• Comparison of
developed and
developing countries.
Figures 1-5 and 1-6
Economic Development
• More Developed
Countries (MDC): 1.2
billion people
– ~20 % population
– Highly industrialized
– High average per capita
GNP
– 85 % of world wealth &
income
– Uses 88% of resources
– Creates 75% of wastes
– US, Japan, Canada, parts of
Europe
• Less Developed
Countries (LDC): 5.2
billion people
– ~80% of population
– Low to moderate
industrialization
– Average per capita GNP
below $4000
– 15 % of world wealth &
income
– Africa, Latin America, and
parts of Asia
Environmental Impact
P (population) X A (affluence) X
T (technological impact/unit of use)
= I (Environmental impact)
Ecological Footprint or Environmental Impact
Amount of land needed to produce the resources
needed by an average person in a country
National Geographic Video
• National Geographic Channel Videos:
Human Footprint
Resources
• Ecological
– Habitat, food,
shelter
• Economic
– Renewable
– Non renewable
– Potentially
renewable
Sustainable Development
• Assumes the right to use
the earth’s resources and
earth capital to meet needs
• Obligation exists to pass
the earth’s resources and
services to future
generations in as good or
better shape than
condition when passed to
us
Four Scientific Principles of
Sustainability: Copy Nature
• Reliance on Solar
Energy
• Biodiversity
• Population Control
• Nutrient Recycling
Figure 1-16
Tragedy of the Commons
• Written by Garrett Hardin
• Concerns over-use of common
property
• Clean air, open ocean and its fish, wild
life species, publicly owned land, gases
of lower atmosphere, space
Globalization
• Social, economic and
environmental change that leads to
an increasingly integrated world
• Economic, information and
communication, environmental
effects
Information Revolution and
Globalization
• International trade of
goods increased
• Transnational
corporations from 7,000
to 53,000
• Phones –from 89 to 850
million
• Passenger kilometers –
from 28 million to 2.6
trillion
• Infectious microbes
transported
RESOURCES
• Perpetual: On a human time scale are
continuous.
• Renewable: On a human time scale can be
replenished rapidly (e.g. hours to several
decades).
• Nonrenewable: On a human time scale are
in fixed supply.
Pollution
• Found at high enough
levels in the
environment to cause
harm to organisms.
– Point source
– Nonpoint source
Figure 1-9
Environmental Worldview
• Planetary Management or
Anthropocentric
– We are in charge of nature, always
more to use, all economic growth is
good.
• Earth Wisdom
– Nature for all of earth’s species, not
always for more use, make a judgment
call about economic growth.
Resource Conservation
• 1903-Theodore Roosevelt
– Set aside Pelican Island, FL to save the
brown pelican
• 1905- Gifford Pinchot
– Formed US Forest Service
• Philosophy: “Resources should be saved to be
used for the greatest good, for the greatest
number, for the longest time.”
Moral / Aesthetic Nature Conservation
• John Muir, Sierra Club founder
• “Fundamental right of organisms
to exist for it’s own sake. . .”
Aldo Leopold’s Environmental
Ethics
• Individuals matter.
• … land is to be loved
and respected is an
extension of ethics.
• We abuse land because
we regard it as a
commodity…
Figure 1-A
Cultural Changes
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Hunter gatherers:
12,000 years ago
Agricultural
revolution: 10,00012,000Industrial revolution:
275 years ago
Technological
revolution: 50 years
ago
Cultural Changes and the
Environment
• Agricultural revolution
– Allowed people to stay in one place.
• Industrial-medical revolution
– Led shift from rural villages to urban society.
– Science improved sanitation and disease control.
• Information-globalization revolution
– Rapid access to information.
Hunting and Gathering Societies
• Nomadic, living in small bands
• Population in balance with food supply
– High infant mortality
– Life expectancy 30-40 yr.
• 3 energy sources
– Sun
– Fire
– Muscle power
Agricultural Societies
• Settled communities
• Slash and burn cultivation to
fertilize nutrient-poor field by
ashes
• Shifting cultivation
• Subsistence farming
Effects and Environmental Impact of
Agricultural Revolution
• Urbanization and agricultural
expansion, cut down forests,
destroyed habitats, soil erosion and
desertification
• Birth rate faster than death rate
causes population increase
Early Industrial Societies (Mid 1700’s)
• Wood used up; resulted in coal usage
• Steam generation
• Fossil fuel-powered farm machinery
– Less farmers needed
– Moved to cities
Advanced Industrial Societies (1914 ---)
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Increase in agricultural products
Lower infant mortality
Improved health
Increase in longevity
Net population increase