Transcript Ch1-Environ Probl Sustain Easter Islnd - Journigan-wiki

Chapter 1: Introduction
Environmental
Problems, Their
Causes, and
Sustainability
Earth Rise
Environmental Science
• Understand how natural world works
• Understand how human systems interact with
natural system
• Accurately determine environmental problems
• Develop and follow a sustainable relationship
with natural world
Themes
Sustainability: A process can continue indefinitely
without depleting resources used *no sacrifice to
future generations*
Stewardship: Caring for something that does not belong
to you
Science: Use the scientific method and question
authority
Ecosystem Capital: Essential goods and services like
food, water, and fuel
Policy and Politics: Human decisions determine what
happens to the natural world
Globalization: The interconnectedness of human
activities, ideas, and cultures
•Rachel Carson was a scientist who wrote Silent
Spring in 1962.
•It addressed the growing use of pesticides (DDT)
and their unpredicted effects on song birds.
•Original users of pesticides did not know that the
poisons used to kill insects would accumulate in
other living things and kill them too.
BIOACCUMULATION
Talking Points (pg.3 Raven)
Environmental sustainability is based (in part) of
what key ideas?
• Understanding effects of our action on health
and well-being of all natural systems.
• Earth’s resources are finite.
• Understand ALL costs to environment/society
associated with what we consume.
• We must all share the responsibility of
environmental sustainability.
Evidence We are not Operating
Sustainably
1. Using non-renewable resources as if in
infinite supply.
2. Using renewable resources faster than
they can replenish.
3. Introducing toxins faster than Earth can
absorb them.
4. Population growth continues to rise,
despite finite resources.
World Population Graph
Environmental Science
• Humanities relationship between:
1.Other living organisms and
2.Our nonliving physical environment.
IPAT Model
I=PXAXT
I = Impact to environment
P = population
A = affluence/amount of resources
consumed
T = environmental effect of technology used
to obtain and consume the resource
Endocrine Disruptors
• Industrial/agricultural chemicals that mimic
or interfere with the endocrine system
(hormones) in people and wildlife.
• Examples: DDT, dioxine, heavy metals,
kepone, dieldrin, chlordane, endosulfan
and plastics (phthalates).
Hormones
• Hormones are chemical messengers that
regulate growth, reproduction and other
biological functions.
• Endocrine disruptors mimic, estrogen (F),
androgen (M) and many thyroid hormones.
Juvenile Alligators Lake Apopka
• Lake contaminated in 1980’s with DDT
and agricultural chemicals
• Feminization of males
• 40% hatch rate, ½ die within 10 days
Georges Bank Fishery Closed
• In 1994, US Department of Commerce
closed two large sections of the 16, 500
km2 fishery off the coast of New England
due to overfishing.
Georges Bank Fishery Closed
Lessons from a Small Island
Easter Island
(Rapa Nui)
http://www.netaxs.com/~trance/rapa.ram
Easter Island Home Page and Music
http://www.netaxs.com/~trance/rapanui.html
Map of
Easter Island
Area - 166 km2
In the 4th
century A.D
there were
approximately
10,000 people
living here
Use of resources
Natural Resources
• Fresh water
• Trees
• Fish
Brought by settlers
• Chickens
• Sweet potatoes
• Taro
• Yams
Used for:
• Building houses
• Food
• Clothing
• Technology
– Stone statues (moai)
– Needed many trees to
move the statues
Moai
• There are 887 moai on Easter Island
•Average Height:
13.29 feet (4.05 meters) some are
more than 20 feet (6 meters)
•Average weight:
13.78 tons
Dutch explorers arrive in 1772
• 600 people left
• Constant war
• Few of the natural resources left
What happened!
4 Global trends:
A.
B.
C.
D.
Population growth and economic
development
Decline of ecosystems
Global atmospheric changes
Loss of biodiversity
A. Human population growth
Note:
•This graph is from 1999.
•These predictions are
based on a faster growth
rate.
•Carrying capacity is
higher in this graph.
• More than 6.6 billion people currently
• We are adding 76 million people per year
• increase pop → increase need for resources
Different lifestyles have different
demands on the environment
Developed (industrialized) countries like America
• hot running water
• more than one car per family
-VSDeveloping countries like Tanzania
• hunting/gathering
• Firewood for heat and cooking
• 1 billion + people live in poverty
B. Soil degradation
Demand for food destroys the soil
– erosion
– minerals in soil are depleted
– salinization
– increased use of pesticides
– overuse of fresh water
C. Global Atmospheric Changes
Global Warming
– CO2 produced from fossil fuel burning acts like a
blanket around the earth.
– Plants take CO2 out of the atmosphere through
photosynthesis
• 6CO2 +6H2O => 602 + C6H12O6
Ozone depletion
– Chemicals released from the surface of the earth
destroy our ozone shield.
– No stratospheric ozone, no protection from the UV
rays of the sun.
Carbon Dioxide Levels
Ozone
D. Loss of Biodiversity
• Habitat destruction leads to a loss of many species
starting with the plants
• exact # of species lost is unknown because not all
species are identified
• strong ecosystems need biodiversity
• 1959-1980 25% of all prescription drugs from natural
resources
• Wild species keep domestic species vigorous
• Aesthetics
A sustainable future is possible
• Nutrition levels and life expectancy
are rising
• Population growth rates are falling
• It is cool to be “green”
• YOU are taking this class
Lessons from a Small Island
Easter Island
(Rapa Nui)
http://www.netaxs.com/~trance/rapa.ram
http://www.netaxs.com/~trance/rapanui.html