Humans effect the “CYCLES”
THE EFFECT OF HUMANS ON THE CARBON CYCLE :
Carbon is introduced into the atmosphere in several ways:
• Animal and plant respiration,
• burning of biomass,
• volcanic eruptions,
• machinery (factories, vehicles and electricity power plants),
• decay of biomass.
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There are several things that will take carbon out of the atmosphere:
• photosynthesis by land plants,
• oceanic phytoplankton, and
• some bacteria.
• The ocean is a large carbon sink holding carbon dioxide in many forms.
HOW ARE HUMANS EFFECTING IT ?
Normally what went into the air and what was taken out was in balance. Man
came along and increased carbon dioxide (CO2) emissions by burning large
amounts of fossil fuels and cutting down large amounts of forests. According to
dictionary.com fossil fuels are “a natural fuel such as coal or gas, formed in the
geological past from the remains of living organisms.”
IN the natural carbon cycle there are two main processes :
Photosynthesis & respiration . Humans interfere with the carbon cycle during the
combustion of any type of fossil fuel, which may include ; oil , coal or natural
gas. Fossil fuels were formed a long time ago. The carbon is said to be "fixed" in
place and is essentially locked out of the natural carbon cycle. Humans intervene
during by burning the fossil fuels. During combustion in the presence of air
(oxygen), carbon dioxide and water molecules are released into the atmosphere.
Since the onset of the industrial revolution about 150 years ago, human activities
such as the burning of fossil fuels and de-forestation have accelerated and it has
contributed largely to a long term rise in the co2 I in the atmosphere.
How do humans effect the nitrogen cycle ?
What is the nitrogen cycle?
Nitrogen is a major component of the earths atmosphere . t enters the food chain
by means of nitrogen-fixing bacteria and algae in the soil. This nitrogen which
has been 'fixed' is now available for plants to absorb. Along with much more.
What are humans effect on the “Nitrogen cycle”?
When we cause nitrogen overload in an ecosystem, there are many drastic
effects. Dumping of raw sewage contains nitrogenous
wastes, along with urban runoff. When large amounts
of nitrogen collect in a water body, eutrophication can
result. This is an accumulation of excess nutrients
which causes an algae bloom. The algae rapidly
deplete all of the oxygen in the water, making it
inhospitable for fish and other aquatic organisms. Also
by burning fossil fuels and wood it releases a large
amount of nitric acid in the atmosphere. Nitric oxide
can combine with oxygen and create nitrogen dioxide
which reacts with water vapor .This can precipitate and
create a deadly acid rain. This can kill trees and fish. This is all because of the
drastic amount of sewage created from humans.
Definition of eutrophication according to dictionary.com: “ excessive richness of
nutrients in a lake or other body of water, frequently due to runoff from the land,
which causes a dense growth of plant life and death of animal life from lack of
oxygen”.
What is The weathering and rock cycle ?
The weathering cycle is a series of events that take place.
Weathering :
There are (3) types of weathering;
-physical weathering
Physical weathering is caused by physical changes such as changes in
temperature, freezing and thawing, and the effects of wind, rain and
waves.
-chemical weathering
The weathering of rocks by chemicals is called chemical weathering.
Rainwater is naturally slightly acidic because carbon dioxide from the air
dissolves in it. Minerals in rocks may react with the rainwater, causing the
rock to be weathered.
-biological weathering
Animals and plants can wear away rocks. This is called biological
weathering. An example, burrowing animals such as rabbits can burrow
into a crack in a rock, making it bigger and eventually splitting the rock.
There are of course other examples.
How do humans effect this ?
It is said that humans don’t have significant impact on the weathering cycle
because it is under water and it is also said that the sewage waste that humans
produce can intervene in the rock cycle. Mostly the physical weathering aspect.
The rock cycle
There are (3) main types of rock:
-Igneous rocks
-Metaphoric rocks
-Sedimentary rocks
The Earth's rocks do not stay the same forever. They are continually
changing because of processes such as weathering and large earth
movements. The rocks are eventually
recycled over millions and millions of of
years. This is called the rock cycle.
An example would be sedimentary rocks
can be changed into metamorphic rocks,
and these can be weathered and the pieces
transported away. These pieces could be
deposited in lakes or seas and eventually
form new sedimentary rock. Many routes
through the rock cycle are possible.
How are humans effecting it?
The rock cycle is a process where rocks erode and the products of erosion
eventually produce more new rocks. The erosion may be physical /
mechanical or it may be chemical. New rocks will be formed by compaction
after sedimentation by wind or water. Humans affect the erosion stage.
Acid rain vastly increases the rate of chemical destruction of carbonate
rocks in particular. Humans alter drainage by digging drainage channels or
building dams. Both affect the transportation and sedimentation of
weathering products.
BIBILIOGRAPHY
http://www.ehow.com/about_6567932_can-weathering-affecthuman-living_.html
http://www.google.com/search?client=safari&rls=en&q=rock+cycle&oe=UTF
-8&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=1TA0TLoNcH00gG615G6Ag&biw=1045&bih=599&sei=1zA0T73FI4Lq0gGS0YTCAg
http://www.experts123.com/q/how-do-humans-interact-with-the-rockcycle.html
http://www.bbc.co.uk/schools/ks3bitesize/science/environment_earth_unive
rse/rock_cycle/revise9.shtml
http://wiki.answers.com/Q/What_effect_does_the_rock_cycle_have_on_huma
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