Transcript Applied Ecology

Applied Ecology
Managing the environment for
human survival and the survival of
nature.
Are you a treehugger?
• Biodiversity is desirable
– Everybody likes wildlife: especially hunters
– Diverse ecosystems are more healthy AND
PRODUCTIVE (think forests and fisheries)
• Biodiversity is probably important
– We know having lots of species keeps food webs
working (for hunting, fishing, logging…)
– Biodiversity makes ecosystems robust (adaptable)
• Biodiversity is at odds with
– Human population
– Human food production
– Human energy production
Issues
• Resources: coal, oil, ore, wood, fiber, food
– Finite or infinite
– Renewable or non-renewable
– Most are finite and non-renewable: they will run out
• Pollution: materials nature can’t get rid of
– Air, soil, water, noise, light, heat
– Toxins, carcinogens, greenhouse gas, acid rain
– Trash, plastics, sewage, medications
• Energy
– Fossil fuels
– Alternative energy
– nuclear
• Habitat: us vs. them
• Us--human population
Big problems
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acid rain: sulfur from coal smoke make rain acid
climate change: CO2 traps heat in Atmosphere
Smog: car exhaust + water + UV
radioactive waste
Heavy metals (Pb and Hg): from coal smoke
toxic waste: mostly from making plastics
Landfills (garbage)
farm chemicals: pesticide, herbicides, fertilizer
ozone hole: freon (CFC’s) from air conditioners eats ozone 10
miles up. O3 blocks UV
• Endangered species
• Critical habitat loss
• Exotic species like emerald ash borer or sea lamprey
Pollution
• anything undesirable that nature can’t
get rid of (too much or too persistent-not biodegradable)
• Type, source, toxicity, half life
• Soil stays put: this can be good
– Dust can blow all the way from China
– Soil erodes and forms lake sediments
• Air and Water move: this can be good
– Tall smoke stacks are used to make air
pollution someone else’s problem
General pollution issues
Source
– Point source: large sources like power plants and
factories and sewage plants
• Easier to deal with
• Filters, scrubbers, storage
• Legislative responses--taxes, fines, inspection
– Diffuse source or dispersed
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like cars
your trash and toxic chemicals
Farm and yard chemicals
Hard to control
• Action of chemicals
– Toxic: hurts or kills cells--CO (carbon monoxide), Hg,
Pb,
– Carcinogenic: causes cancer--DDT, radiation, dioxin,
UV light
– Mutagenic: causes mutations or birth defects-radiation, dioxin (PCB)
– Other
• CFC’s (chlorofluorocarbons) damage ozone (O3)
• DDT (Pesticide) makes bird egg shells too thin
• Hormone mimics: many chemicals from making plastics
involved with breast cancer by mimicking hormones
• CO2 traps heat in the atmosphere
• Smog: car exhaust, water, light forms ozone that hurts lungs
and eyes.
• Persistence of chemicals: how long does it
last (half life)
– Biodegradable: breaks down naturally
• Plastic is forever: all the plastic ever made still exists!
– Persistent: DDT lasts a long time
• DDT is a pesticide banned in the 1970’s: it almost made
Eagles extinct by weakening their egg shells
• Bio accumulation: moves up food chain
• May move far from source
Response to Pollution
• Legislation: signed by Richard Nixon in the
1970’s. This is the reason you think pollution
is no problem.
– Clean water act
– Clean Air act
– Endangered species act
Superfund act
– Executive order creates EPA
– States create agencies like MPCA
• International agreements
– Montreal Protocol: (1989)--CFC controls
– Kyoto protocol: (1997)--CO2 and global warming
Response to Pollution
• Community action
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Ducks unlimited
Greenpeace (save the whale)
Sierra club (created boundary waters)
World Wildlife fund: endangered species
Conservationists with common sense (CWCS)
Earth First: radical action
Union of Concerned Scientists (doom’s day clock)
Nature Conservancy--buys critical habitat and
donates for park land.
– Wilderness Society: education
Response to Pollution
• Personal choices
– Conservation: use less
• Energy, water, plastic, chemicals
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Recycling
Composting
Safe disposal
Activism: trying to cause change and influence others.
Participation in government
Vegetarianism
Transportation
• Technology: energy, food, transportation, housing
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WHAT TO DO
CONSERVE
a)
REDUCE
b)
REUSE
c)
RECYCLE
ALTERNATIVE ENERGY: CARBON FREE
a)
WIND
b)
PASSIVE SOLAR
c)
PHOTOVOLTAICS
d)
GEOTHERMAL
e)
HYDROELECTRIC
f)
BIOFUELS (SOY DIESSEL, ALCOHOL FROM CORN)
g)
NUCLEAR
CRAZY NEW INVENTIONS
a)
FUEL CELLS: use hydrogen to make electricity
b)
SPACE COLONIES
c)
UNDERWATER CITIES
d)
FUSION POWER: like on the sun
POPULATION CONTROL: ZPG
Education: personal choice
Alternative economies: ecotourism, green energy,
CLIMATE CHANGE
• Sometimes called “global warming”
• Involves the “Greenhouse Effect”-greenhouse gasses trap solar energy in
the atmosphere causing heating. Like
glass in a greenhouse or the glass in
your car.
• Greenhouse gasses: CO2, water vapor,
CH4
• Earth needs some greenhouse effect to
prevent an ice age! It’s natural
What do we know for sure
• The climate has warmed a lot in the last 100
years. This is really bad.
• The climate has warmed faster than ever.
• CO2 levels are higher than ever.
• The CO2 is from combustion of fossil fuels.
• CO2 is a greenhouse gas.
• The climate has been hotter and colder than
it is now. It has not changed so quickly.
Effects of Climate change
• Sea level rises
• Continental glaciers are melting
– Warmer water expands
• Climate become weird
– More dry and more wet
– Colder and warmer
• Habitats shift north or try to
• Plants grow better--more CO2
What can we do
• Conservation: reduce your carbon
footprint--small cars, drive slow, carpool,
public transportation, CFL’s, turn off
electronics, turn down the heat
• Carbon sequestration--store CO2
• Plant trees
• Alternative energy
• Is there a down side to using less fossil
fuels?
Human population
• Population Growth
– Limits to Growth
• Human Demography
– Fertility and Mortality
– Life Span and Life Expectancy
– Distribution: where are we
• Family Planning
– Birth control
– Family size
– Zero population growth
• The future: 10 billion by 2030 then level off
Human Population History
Population Growth
• World War II (1939-45) killed about
40 million people in 6 years
• Global population 2 billion +
• Growth about 2% a year
• Population growth 40,000,000 per
year
• Population growth 110,000 per day
• At no time did the war offset
population growth
Carrying Capacity of Earth
• Solar Energy about 10,000 times
global energy use
• Global energy use = sunlight on
20,000 square miles
• Globally about 1/3 of arable land is
used for crops
• If U.S. (5% of population) uses 25%
of resources, will take 5 times
earth’s resource output to raise
everyone to our level
Carrying Capacity of Earth
• Solar Energy about 10,000 times
global energy use
• Global energy use = sunlight on
20,000 square miles
• Globally about 1/3 of arable land is
used for crops
• If U.S. (5% of population) uses 25%
of resources, will take 5 times
earth’s resource output to raise
everyone to our level
What Drives Population Growth?
• Fastest growth in Africa and South Asia
• Many of the fastest growing countries are
Moslem
• Economic value of large families (farm
labor, elder care and support)
• Status attached to high fertility
DEMOGRAPHY
• Vital statistics about people such as births,
deaths, race, ages. distribution, and
population size.
• October 12, 1999, UN officially declared
the human population reached 6 billion.
– Estimation at best.
FUTURE OF HUMAN
POPULATIONS
Most demographers believe the world
population will stabilize sometime during
the next century.
• Projections of maximum population size:
– Low
8 billion
– Medium 9.3 billion
– High
13 billion
• Where will they live?