Human Activities & the Earth-Nov15-EcologyWaterAir
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Transcript of Human Activities & the Earth-Nov15-EcologyWaterAir
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Human Activities and the Earths
Valuable Water and Air Resources
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Ozone Depletion
Global Warming and Global Climate Change
Acid RainBiological Magnification
Human Impacts on Water, Air, Fisheries
What we can do
Objectives:
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Ozone layer (20-50km up) protectsthe Earth from UV radiation
Gases (CFCs) used in aerosols break
down ozone causing the holes over theArctic and Antarctica
Montreal Protocol stopped productionof CFCs on January 1, 1996
Holes are not growing but will not recover until
. . . . . . . 2065!
Ozone Depletion
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Excess UV radiation:Skin cancerCataractsImmune System Problems
Other unknown effects on plant/animal life
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Caused by gases (mostly CO2) that trap heat
Burning of fossil fuels, cutting/burning of forests
releases CO2 faster than Carbon cycle canremove it
Temperatures have risen 0.6oC. since industrialage
Since 1980, average temp risen 0.3
O
C.
Global Warming
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Global Warming
Global Climate ChangeMelting of permafrost, increasing release of
greenhouse gases
Melting of poles
Rising sea level
Flooding, Drought
Loss of habitat, species extinction
Loss of coral reef ecosystems (fisheries, touristrevenue, natural storm barriers)
All the above have economic impacts
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Acid Rain
Burning of fossil fuels release nitrogen and sulfurgases
Combined with H2O vapor = nitric and sulfuric acidsFall as acid rain
Plants damaged
Soil chemistry altered, potentially hazardouscompounds released and flow into water system(mercury) BIOMAGNIFICATION
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Eastern U.S:
average pH of 3.6,
with some valuesas low as pH 2.6
Los Angeles:
pH of fog has
been measuredat 2.0
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Biomagnification
Pesticides and heavymetals work their way
into rivers or lakes andmove up the food chainbecoming moreconcentrated at each level
Silent Spring by RachelCarson
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FOR EXAMPLE:
If in one day a small fish eats 1,000 plankton and a larger fish
eats 1,000 small fish, the human who catches the larger fish
is ingesting all the toxins that were in a 1,000,000 plankton!(1,000 x 1,000 = 1,000,000)
Add that up over a lifetime and youre in trouble!
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Clean Water
Renewable but not unlimited!same water is recycled (the water cycle!)BUT if contaminated during that cycle, may not be
reusable
Two issues: Pollution and loss of water filtration!
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Some water pollutant sources:
Sewage
Runoff: agricultural fertilizers, factory farms
Factory outfall
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Contaminated drinking water
Contaminated food animals (biological magnification
of toxins from the environment over their life spans)Unbalanced river and lake ecosystems that can no
longer support full biological diversity
Deforestation from acid rainLoss of natural beauty
Some Effects of Water Pollution
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For water use to be sustainable we need to protect the natural
systems of the water cycle.
Preserve wetland areas = water filtration
Think before you pave it = less filtration
Think before you cut it = less transpirationllllllllllllll
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Fisheries
Overfishing - harvesting fish
faster than they reproduce
An example of tragedy of thecommons
Everyone uses the resource but no one
maintains it
If properly managed, can be a renewable
resource
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Air
Air Quality Issues (caused by burning offossil fuels):
SmogParticulates - microscopic particles of ash and dust
Acid Rain
Their Effects:
Human healthDeforestation
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Dont litter
Turn off lights, all electronic equipment
Recycle - dont fill up our landfills
Conservative or little use of fertilizers
Walk or bike when possibleDrive more fuel efficient vehicles
Support wetlands preservation
Develop sustainable energy sources: Wind, solar, fuel cells
Think before you pave it
Use sustainable building practices - green space and gravel,
porous paving
Design pedestrian friendly cities
Things we can do