human activities & the earth-nov15-ecologywaterair

7/30/2019 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

human activities & the earth-nov15-ecologywaterair

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