Introduction for urban development.Conversion of forestland to farms, ranches,

Introduction

a)
Eutrophication

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Eutrophication or more
precisely hypertrophication, is a water body enriched with
nutrients,with an excess amount of it.Certain nutrients are needed for survival of the
living thing.Primarily,nature is efficient enough to provide right amount of
nutrients,not less nor too much. This is absolutely true in aquatic ecosystems
because they are so dynamic.Water will be oligotrophic if there is too much
nutrient.
Consequently,serious problems will occur if there is no nutrients in the
aquatic environment of the organisms.However,
problems can also occur when there is too much nutrients too. When this occur
we get eutrophication. A eutrophic stream, river or lake occurs when too many nutrients,such
as nitrogen and phosphorous, are present, usually as a result of overflow of
the land. Algae, plankton and other microorganisms attracted to these types of
nutrients, and when they are too much these aquatic organisms can take over.
When eutrophication occurs in a lake, river or other aquatic system,it gives a
negative impact on the organisms itself including humans,birds and fishes.

b)
Deforestation

Clearing of trees or removal
of trees from the forest to make it into non-forest is called deforestation and
it is also used for urban development.Conversion of forestland to farms, ranches, or urban use are also examples of deforestation.Tropical rainforests are the most common deforestation
area.One
of the largest and severe issue in global land is none other than deforestation.
Croplands and grazing lands are estimated area regarding deforestation which
includes cutting down trees for wood products and so on due to urban usage.Due
to this,whole forest is no more and wiped out due to no more trees left in the
forest. In some cases,forest structure would be altered if illegal logging and
so called accidental fire occurs.The practice of slash-and-burn agriculture is the major contributor for
deforestation.Small-scale farmers clear land produces for only a few years
and then must forests by burning them and then grow crops in the soils fertilized by the
ashes.In Southeast Asia such as Indonesia, tropical Africa, and the Americas
for permanent oil palm plantations practice open fire burning to clear
out the forests.

 

 

c) Global Warming

The
observed century-scale rise in the average temperature of the Earth’s climate
system and its related effects called
Global warming commonly known as climate change,The
increase of average world temperatures as a result of what is known as the
greenhouse effect is global warming too. In greenhouse,certain gases in the
atmosphere acts like glass, sunlight is allowed to heat the earth’s surface but
it radiates back to the space if we trap the heat. The Earth gets hotter when
the greenhouse gases build up in the atmosphere.Consequently,this phenomena is
called climate change.Since the mid-20th century the Scientist
have gathered detailed observations of various weather phenomena
(such as temperatures, precipitation,
and storms) and of related influences on climate (such
as ocean currents and
the atmosphere’s chemical composition). Earth’s climate indicated that it has changed over almost
every conceivable timescale since the beginning of time and that the influence
of human activities
since at least the beginning of the Industrial
Revolution has been deeply contributed to the climate
change.

d) Ozone depletion

Ozone is very important
and crucial to us and gives us the pros and cons.As
a result of many chemical reaction regarding air pollution which caused by
heavy traffic and UV light formed ozone near the ground which eventually caused
a lot of respiratory problems particularly for children and the elderly.However,the stratosphere, ozone filters out incoming radiation from the Sun in the
cell-damaging ultraviolet (UV) part of the spectrum are known as high up in the
atmosphere in a region.Life on earth would not have evolved in the way it has
without this ozone
layer. Single-celled
organisms such as algae that make up the bottom rung of the food chain inhibits
the reproductive cycle of phytoplankton with the help of extra UV B radiation
shone onto Earth.The only thing fears the Biologist is that reductions in other
animals due to low number of phytoplankton..Excess ultraviolet
B.Chlorofluorocarbons (CFCs), chemicals found mainly in spray aerosols heavily used by industrialized
nations for much of the past 50 years, are the primary culprits in ozone layer
breakdown which ultimately causes the change in the reproductive rates of young
fish, shrimp, and crabs as well as frogs and salamanders.UV breaks down into substance
such as chlorine due to CFC in the upper atmosphere exposed to UV.Chlorine
reacts with the oxygen particle and tears down the ozone.

e)
Pollution

When pollutants contaminate the natural
surroundings; which changes our normal lifestyles quickly is called pollution.Our
ecosystem and the balance in the environment are disturbed due to pollution.
Pollution occurs in Different forms of pollution can be found such as air,
water, soil, radioactive, noise, heat/ thermal and light.There are two sources
of pollution occurrence; the point and the non-point sources.The non-point
sources are hard to control whereas the point sources are easier to
identify,monitor and control.Firstly,Air pollution
is a contamination of natural air with dangerous gases.It is one of the major
contributor to environmental pollution.  Land
pollution occurs due to excess of dumping of toxic waste. This can be a
chemical or other waste material.Sound pollution called as noise
pollution is a disturbance of silent environment with loud noises.Radiation pollution
is the pollution due to abnormal radiation in the environment. This occurs due
to use of radioactive elements from atomic energy stations.Thermal pollution
arises because of excess heat from thermal power plants, industries involved in
metal molding.Water pollution is mainly about harmful toxic substances
thrown by ignorant humans or released as residue by irresponsible companies.In
other cases,ships release their unwanted oil into the sea.

f) Acid deposition

Any other form of precipitation that is
unusually acidic, elevated levels of hydrogen ions (low pH) is known as Acid
deposition.Plants, aquatic animals and infrastructure had negative impacts due
to acid deposition.Emissions of sulphur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids is called acid deposition.Wet and dry are the two types of
deposition.Rain, snow, fog, hail or even dust that is acidic are included in the
type of acid deposition.Dry
deposition consist of acidic particles and gases from atmosphere in the absence
of moisture.During atmospheric the acidic particles and gases may deposit to
surfaces (water bodies, vegetation, buildings) quickly or may react to form
larger particles that can be harmful to human health. This acidic water flows
over and through the ground, and can harm plants and wildlife, such as insects
and fish when the accumulated acids are washed off a surface by the next rain.The
amount of rainfall an area receives depends on the  amount of acidity in the atmosphere that
deposits to earth through dry deposition.For instance,the ratio of dry to wet
deposition is higher than an area that receives several inches of rain each year
in the desert areas.

Causes and why it happens

A)
Eutrophication

Fertilizers (nitrates
and phosphates)

Ignorant human actions predominantly causes Eutrophication.Nutrient
accumulation consists of agricultural
practices and the use of
fertilizers on lawns, golf courses, and other fields. Surface runoff into
lakes, rivers, oceans and other surface waters washes away these nutrients with
high concentrations of phosphorous and nitrogen when it rains, photosynthesis
activity of the hungry plankton, algae and other aquatic plant life increases and
well fed.Dense growth of algal blooms and plant life in the aquatic
environments are the consequence of this.

Concentrated animal
feeding operations

Phosphorus and nitrogen nutrients and Concentrated animal feeding
operations (CAFOs) are the main contributor for eutrophication. The nutrients are
normally discharged through animal feeding that finds way into rivers, streams,
lakes, and oceans whereby accumulation occur in large quantity with recurring
cyanobacterial and algal blooms plaguing the water bodies.

Direct sewage
discharge and industrial waste into water bodies

 Sewage
water is directly discharged into water bodies such as rivers, lakes, and
oceans in some parts of the world, especially the
developing nations. As a result, it stimulates the dense growth of algal blooms
and other aquatic plants which threatens survival of aquatic life in many ways
due to the newly introduced high amounts of chemical nutrients.

The sewage water may also be treated by some countries,but it is still
discharged into the water after the treatment. Causing of the accumulation of
excess nutrients, ultimately bringing about eutrophication,as much as the water
is treated. Similar outcomes are present when direct discharge of industrial waste
water into water bodies.

 

 

Natural events

Floods and the
natural flow of rivers and streams are natural events which can prevent excessive
growth of algal blooms by washing away the excess nutrients off the land into
the water systems.Accumulation of sediments as well as phosphorus and nitrogen
nutrients which contribute to the explosive growth of phytoplankton and
cyanobacterial blooms will occur as lakes grow old.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The process of Eutrophication

Two essential nutrients such as Nitrogen (N) and Phosphorus
(P) are needed by aquatic plants (like any other plants) to grow.Small amounts
of nutrients required and occur in a healthy lake. But,major water pollution problem will be created if in
large quantities.The rapid growth of plants and algae, clogging waterways and
sometimes creating blooms of toxic blue-green algae due to stimulation of too
many nutrients.Eutrophication is the processs.Result of this, large
amount of oxygen (O2) are used up due to the
death of plants and decomposition of algae.So.fish and other aquatic species
oxygen level will be reduced from the availability.A complete oxygenless
environment that can support nothing except a few species of anaerobic bacteria
will occur in extreme cases.Fish and other aquatic life will be killed and the
aesthetic and recreational value of the lake would be reduced.Nitrates are the
nutrients found in sewage and fertilizers, and phosphates found in detergents
and fertilizers.A process called cultural eutrophication is the human inputs of nutrients from
the atmosphere and from nearby urban and agricultural areas can accelerate
the natural eutrophication of lakes.
Domestic sewage, industrial wastes and storm
drainage are the examples where nutrients from urban sources derived.There is a
considerable range where the contribution of nitrogen and phosphorus per person per day averages 10.8 g
N and 2.2 g P.Detergents were developed containing sodium tripolyphosphate,
which softens water by neutralizing calcium and keeps dirt in suspension once
it has washed off clothes in the   
1940s.Cultural eutrophication in lakes happens due to the principal
sources of nutrient overload.Types and amounts of human activities occurring in
each airshed and watershed varied according to amount of each source.

Refer to Appendix A for further information

 

 

 

B) Deforestation

Agricultural Activities

 One of the major factors affecting Deforestation
is agricultural activities.Huge amount of tress are fell down to grow crops and
for cattle gazing due to overgrowing demand for food products.

Illegal Logging

Substantial
amount of wood supply are prominent for wood based industries like paper,
match-sticks, furniture etc., Therefore trees are chopped for supplies since wood
is used as fuel both directly and indirectly.Examples of wood being used as
fuel are firewood and charcoal.These industries thrive on illegal wood cutting
and felling of trees

Urbanization

The
construction of roads are undertaken; here again trees are chopped to create
roads in order to gain access to the forest.Forest covers, as with the expansion
of cities more land are affected by too direct overpopulation needs to
establish housing and settlements.Hence,forest land is reclaimed.

Desertification of land

Desertification
of land is the some of the other factors that lead to deforestation are also
part natural and part anthropogenic.Growth of trees is not possible due to land
abuse making it unfit.Soil erosion occurs and making it unfit to grow
plants and trees due to many industries in petrochemicals release their waste
into rivers.

Mining

A
considerable amount of forest land is required for oil and coal
mining. Apart from
this,roads and highways have to be built to make way for trucks and other
equipment.Pollution
of the environment occur
and affects the nearby species due to the waste that comes out from the mining.

Forest Fires

Another
example would be forest blazes;Forest fires in various portions of the world
destroys hundreds of trees each year.Extreme warm summers and milder winters.
Fires, whether causes by man or nature results in huge loss of forest cover due
to this.

 

 

Palm
oil 

Palm oil has its potential
as a biofuel and nowadays packaged foods  and beauty products are using palm oil in
it.Another cause of deforestation is palm oil.Many  Indonesian and Malaysian farmers destroy
acres of trees to harvest it due to rising prices make it more valuable.Several
countries are currently debating a ban on palm oil as a biofuel for this reason.

Trees are cut down to
make more room for houses and roads as cities grow larger to accommodate more
people. Now that 50 percent of the world’s population lives in cities, this urban
sprawl deforestation is occurring worldwide.

 

 

 

 

 

 

 

 

 

 

 

Process of Deforestation

Firstly, the main method of clearing trees for small farmers and plantation
owners in the tropics Slash and Burn agriculture. This is because to remove
unwanted parasites and organisms that reside in the desired land is the only
way to do  effectively.During season
between June and October the burning usually happens. 20% of the fires in the
world can be attributed to deforestation during this period. In order to
release the minerals in the trees back into the soil, the trees are cut down
and then later burned.Soil in the tropics so very poor and nutrient deficient
hence minerals are needed in the soil. After the first burn which only lasted
for a few years due to the nutrients that are released into the soil due to
the rain washing them away and their use for agriculture. Between 3 and 20
years after the trees  removed,this can
happen anywhere. In order for the farmer to keep turning a profit, he will
need to clear a new section of land and start over again at this time.

Removing all the trees and vegetation, regardless of species, leaving
the land completely bare is example of clear-cutting a forest.Scientists have
no idea how long it takes the forest to recover since nothing is left on the
land. A method used both to clear the land and harvest trees for commercial
logging purposes is Clear-cutting.The most destructive of all methods because
nothing is left but the soil which is not even replenished by a burn is clear
cutting.

Only certain trees are chosen to be cut down in selective logging.Research
shows that during Selective logging, only about 3% of the trees are harvested
are shown during the research. About 3%, and 49% of the trees are damaging in
the process of harvesting. Selective logging is a relatively short 50 years,the
period that it takes for vegetation to grow back in. This is because there
are patches of tree left to disperse seeds and provide shade for the
developing seedlings from too much sun.
 

Perennial shade agriculture, like selective logging, leaves large areas of
forest intact, so the period of regrowth is also relatively short.  Only
small areas of trees and vegetation are removed in order to leave adequate
shade for the crops.  This method of deforestation is employed by farmer
of crops such as coffee and chocolate, which need the shade of large canopy
trees.  Perennial shade agriculture has one of the fastest recovery
periods of all the processes of destruction.

Refer to Appendix B for further
information

 

 

 

 

 

 

 

 

 

 

 

C) Global
Warming

The main cause of the current global warming trend is human expansion of
the “greenhouse effect” agreed by the most scientist.Heat is blocked in
certain gases at atmosphere from escaping.Climate change are the long-lived
gases that remain semi-permanently in the atmosphere and do not respond
physically or chemically to changes in temperature.Feedbacks are the gases,
such as water vapor, which respond physically or chemically to changes in
temperature.

Gases that contribute to the greenhouse effect include:

Water vapor

The most abundant greenhouse gas, but
importantly, it acts as a feedback to the climate is water vapour.As the
Earth’s atmosphere warms, but so does the possibility of clouds and
precipitation, making these some of the most important feedback mechanisms to
the greenhouse effect,as the water vapour increases.

Carbon Dioxide

A minor but very important component
of the atmosphere, carbon dioxide is released through natural processes such as
respiration and volcano eruptions and through human activities such as
deforestation, land use changes, and burning fossil fuels is Carbon dioxide (CO2).
Atmospheric CO2 concentration increased by humans by more than
a third since the Industrial Revolution began. Climate change is the most
important long-lived.

Methane

A hydrocarbon gas produced both
through natural sources and human activities, including The decomposition of
wastes in landfills, agriculture, and especially rice cultivation, as well as
ruminant digestion and manure management associated with domestic livestock
produce a hydrocarbon gas through natural resources and human activities.Methane
is a far more active greenhouse gas than carbon dioxide, but also one which is
much less abundant in the atmosphere for a molecule-for-molecule basis.

 

Nitrous Oxide

The use of commercial and organic
fertilizers, fossil fuel combustion, nitric acid production, and biomass
burning  by a powerful greenhouse gas
produced by soil cultivation practices.

Chlorofluorocarbons (
CFCs)

Synthetic compounds entirely of
industrial origin used in a number of applications, but now largely regulated
in production and release to the atmosphere by international agreement for
their ability to contribute to destruction of the ozone layer is called
CFCs.Other names include greenhouse gases.

Solar
irradiance

Changes in the sun’s energy output would cause the climate to
change,fundamental source of energy that drives our climate system,the Sun
which is reasonable to assume.Solar variability has played a role in past
climate changes as shown in studies.The average amount of energy coming from
the sun either remained constant or increased slightly since 1750.Scientists
would expect to see warmer temperatures in all layers of the atmosphere if the warming
were caused by a more active sun. Instead, they have observed A cooling in the
upper atmosphere, and a warming at the surface and in the lower parts of the
atmosphere were observed by them.Heat is trapped in the lower atmosphere due to
greenhouse gases.Solar irradiance changes can’t reproduce the observed
temperature trend over the past century or more without including a rise in
greenhouse gases included in the climate models.

 

 

 

 

 

Process of Global Warming

The current increase in
temperature of the Earth’s surface (both land and water) as well as it’s
atmosphere is global warming.Over the last 100 years about two thirds of this phenomena
has occurred since 1975,average temperatures around the world have risen by
0.75°C (1.4°F). The result of natural causes but today it is being caused by
the accumulation of greenhouse gases in the atmosphere produced by human
activities in the past, when the Earth
experienced increases in temperature.

The Earth’s temperature
at a safe level making it possible for humans and many other lifeforms to exist
is maintained by the natural greenhouse effect.However, the greenhouse effect
caused the Earth’s average temperature to rise by almost 1°C due to the
Industrial Revolution human activities. Global warming is created as we see
today.A period of massive climate change, the average temperature change around
the globe was only about 5°C to put this increase in perspective it is
important to understand that during the last ice age.

More than 90% certainty,
that this increase in overall temperatures is due to the greenhouse gases
produced by humans after a long series of scientific research and international
studies has shown.The main sources of these emissions are activities such as
deforestation and the burning of fossil fuels.The national science academies of
all the major industrialized countries recognises these findings.

Many places around the
world is affected by Global warming.The melting of ice sheets, permafrost and
glaciers which is causing average sea levels to rise is accelerated.At the same
time making other places wetter, with stronger storms and increased flooding,the
changing precipitation and weather patterns in many different places,with more
intense periods of drought, making some places dryer.Both nature as well as
human society are affected by these changes and will continue to grow at the
same pace as today as the greenhouse effect is worse day by day.

Refer
to Appendix C for further information

 

 

 

D) Ozone
Depletion

CFC

In the Earth’s atmosphere ozone is a triatomic form of oxygen
(O3).The destruction of ozone consist of a combination of low
temperatures, elevated chlorine, and bromine concentrations in the upper
stratosphere.The leading cause of ozone layer depletion is the production and
emission of chlorofluorocarbons (CFCs). The total depletion of ozone accounts
80% of CFCs

ODS,HCFCs and VOCs

Other ozone-depleting substances (ODS), include
hydrochlorofluorocarbons (HCFCs), and volatile organic compounds (VOCs are
often found in vehicle emissions, byproducts of industrial processes, refrigerants,
and aerosols.In the lower atmosphere of the Earth, ODS are relatively stable,
they are exposed to ultraviolet radiation in the stratosphere and thus, thus to
release a free chlorine atom they need to breakdown.Reaction between free
chlorine atom with an ozone molecule (O3), and forms a molecule of
oxygen and chlorine monoxide.Now,a chlorine atom, and two molecules of oxygen
formed when CIO reacts with an ozone molecule. Chlorine monoxide formed when
free chlorine molecule again reacts with ozone.This results in the depletion of
the ozone layer as the process continues.

Sun-spots

Certain natural phenomena such as Sun-spots and stratospheric
winds affects the Ozone layer. 1-2% depletion of the ozone layer and the
effects are also thought to be only temporary which has been found to cause not
much harm.The major volcanic eruptions (mainly El Chichon in 1983 and
and Mt. Pinatubo in 1991) has also contributed towards ozone depletion was
believed by the scientists.

Unregulated Launches of Rockets

Rocket
launches is another major cause of large scale ozone depletion.Resulting in
much more ozone depletion than CFCs if unregulated rocket is launched,a study
has shown.If rocket launches will be let unregulated then,it is estimated it
would cause huge ozone loss by the year 2050 than the CFCs have done.

 

Global Warming

Ozone
layer depletion also occur due to global warming.Most of the heat is trapped in
troposphere which is the layer below the stratosphere due to global warming and
green house effect. Depletion of ozone layer happens when ozone is present in
stratosphere so heat don’t reaches troposphere and it remain cold as recovery
of ozone layer requires maximum sunlight.

Nitrogenous Compound

NO,
N2O and NO2 are nitrogenous compounds emitted by human activities in small
amount  

considered
to be greatly responsible for the depletion of ozone layer.