Transcript Human Impact on the Earth - Doral Academy Preparatory

Human
Impact on the
Earth
Human Impact on the Earth
Water
 Air
 Land

Our Water Resources
The water cycle is the
continuous movement of water
above, on, and below the Earth’s
surface. It includes:
 Precipitation
•Runoff
•Evaporation
•Condensation

Our Water Resources
Pollution is the introduction of
harmful substances into the
environment.
 Point-source pollution is
pollution that comes from a
single or easily traced point
(such as a pipe).
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Our Water Resources
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Nonpoint-source pollution is
pollution that comes from many
places rather than a single point.
It comes from places like yards,
parks, farms, streets, and storm
sewers and reaches bodies of water
via runoff.
Our Water Resources
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65% of the Earth is water – but only
3% of that water is drinkable.
Freshwater pollution comes from:
• Fertilizer runoff
• Bacteria from waste
• Waste from factories
• Pesticides
Our Water Resources
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The Clean Water Act had a goal to
make all surface water in the US safe
enough for swimming and fishing by
1983.
We have made progress – but that
goal has still not been met.
Our Water Resources
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Our oceans are also polluted, the
most common sources being:
• Trash
• Sludge dumping
• Oil spills

The US spends more than $130
million a year to protect the ocean
and beaches.
The Air We Breathe
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Primary pollutants are pollutants
that are put directly into the air by
human or natural activity.
•Exhaust, volcanic ash, smoke soot
Secondary pollutants form from
chemical reactions.
•Smog
The Air We Breathe
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Acid rain is rain, sleet, or snow
that is highly acidic because of
the burning of fossil fuels.
The ozone hole formed when
some chemicals added to the air
reacted with the ozone layer.
The Air We Breathe

The Clean Air Act allows the
Environmental Protection Agency
(EPA) to control the amount of
pollutants that can be released
from any source.
Burning of Fossil Fuels
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oil burning is responsible for about 30% of
all carbon dioxide emissions to air.
The main function of the carbon dioxide
present in the atmosphere is to trap the
heat obtained from sunlight and do not let
it go beyond the atmosphere.
It is because of the carbon dioxide in the
atmosphere that our planet is warmer
than any other planet of the solar system.
On burning of fossil fuels, various types of
gases like carbon dioxide, carbon
monoxide, methane, nitrous oxide, are
released.
Saving Our Land
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Human causes of erosion:
Deforestation or the process of
clearing forests.
Overgrazing removes large areas of
grassland.
Farming breaks up the soil.
Saving Our Soil
Desertification is a process by
which human activity makes the
soil infertile in areas where
plants could once grow.
 Urbanization is also causes an
impact on Earth, the more a
population grows, the more
resources are going to be used
and the more the land is going to
change.
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