Introduction Eutrophication, which scientifically known as hypertrophication, is

Introduction

Eutrophication, which scientifically known as hypertrophication, is
the water body enrich by nutrients, usually with an excess amount of nutrients.
Eutrophication happens when the environment becomes enriched with nutrients.

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A syndrome of ecosystem responses to human activities that
fertilize water bodies with nitrogen(N) and phosphorus (P), and it often
leading to changes the animal and plant population in water and degradation of
water and habitat quality.

Eutrophication triggered the growth o plants and algae due to the
over biomass load. This causes the oxygen depletion of the water body.
Eutrophication occurs naturally over centuries as lake getting older and are
filled with sediments. But, human activities increase the rate and also the
time of the eutrophication through both point source discharges and non-point
loadings of limiting nutrients. For example, nitrogen and phosphorus was flow
into the aquatic ecosystems. This leads to drastic consequences for water
drinking sources, fisheries, and recreational water bodies.

 

 

 

 

 

Causes
of eutrophication

“Eutrophication
is an enrichment of water by nutrient salts that causes structural changes to
the ecosystem such as: increased production of algae and aquatic plants,
depletion of fish species, general deterioration of water quality and other
effects that reduce and preclude use”.  This is the first definition
given by the OECD (Organization for Economic Cooperation and Development) in
the 70s.

Eutrophication is one of the
serious environmental problem in the world. This is due to it cause the
deterioration of water quality and is one of the major resistance to achieve
the quality of the water established by the Water Framework Directive
(2000/60/EC) at the European level. According to a survey, the International
Lake Environment Committee promotes a project, eutrophication affects 54% of
Asian lakes,53% of those in Europe,48% of lake in North America,41% of those in
South America and 28% of lake in Africa.

All water bodies have a natural and slow
eutrophication process. However, in the recent decade, the water bodies have
undergone a very fast progression of eutrophication due to the presence of
human and their activities, also known as cultural eutrophication. This
cultural eutrophication process continuously increases the contribution of
nutrients, mainly organic load, which is nitrogen and phosphorus until it
exceeds the capacity of the water body. Some main factors change the structural
of the water.

The use of fertiliser:

The use of fertiliser in the soil and agricultural
practices lead to the accumulation of nutrients. Once the nutrient reach high
concentration levels and the ground is no longer able to hold them, they will
be carried by the rain and flow into the river which eventually may flow into
lakes or seas.

Discharge of waste water:

In some countries in the world, especially the
developing countries, waste water is discharges directly into water bodies without
any filtration. For instance, waste water directly discharges into rivers,
lakes and seas. This result the water bodies get a high quantity of nutrients
and it stimulates the uncontrolled growth of algae. In industrialised countries,
waste water can be illegally discharged directly into water bodies. To clarify,
when waste water before discharge into the environment, the filtration are not
appropriate to reduce the organic load, with the consequent accumulation of
nutrients in the ecosystem.

 Reduction of
self-purification capacity: Over the years and centuries, lakes accumulate
large quantities of solid material moved by the water sediments. These
sediments can absorb large volume of nutrients and pollutants. In a result, the
basin is started to fill by the sediments and thus increasing the interaction
between water and sediment. This phenomenon could bring to a further
deterioration of water quality, eventually connected to the process of
eutrophication.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How
it affects the water bodies

Eutrophication happens when the algae is significantly
increase cause by the better availability of one or more growth factor
necessary for photosynthesis, such as sunlight, nutrients and carbon dioxide.

When algae start to grow in an uncontrolled rate,
large biomass is increase and is destined to degrade. In deep water, large
amount of organic substance is accumulating due to the algae almost having the
end of their life cycle. An excessive consumption of oxygen is required to
destroy all the dead algae. An anoxic ,which is oxygen-free environment is thus
created on the lake bottom. At there, there are organism that are capable to
live without oxygen, and they are responsible for the degradation of the
biomass. The absence of oxygen reduces biodiversity causing, even the death of
animal and plant species. All this happens when the rate of degradation of the
algae is greater than that of oxygen regeneration, which in summer is already
in low concentrations.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Example

Fertilisers are often used in agriculture activities.
When the fertiliser is excess, the soil is no longer can hold the nutrients of
the fertilisers, thus it run off into nearby water bodies whenever there is a
rain. The increase of the nutrients level causes the phytoplankton to grow and
reproduce at a very fast rate, resulting in algal bloom.

The algal bloom blocks the sunlight to penetrate
inside the water body and disrupts the photosynthesis process of the marine
plants under water surface. In fact, the algae may also produce toxins that are
harmful to the aquatic life. This can cause problems along the food chain. When
plant under the water surface died, it encourages the growth of detritus.
Detritus may use up all the oxygen to undergoes decomposition process in the
water, causing the biochemical oxygen demand( BOD) level raise. In a result,
there will no any marine life in the water.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Deforestation

Introduction

On the earth, forests cover almost 31% of the land
area. They produce oxygen which is vital to human being and provide habitat to
people and wildlife. Research of a survey, 1.6 billion people rely on benefits
forests offer such as food, water, clothing, traditional medicine and shelter.
Not only that, large number of the world’s most threatened and endangered
animals live in the forests.

Forests bring lots of benefits to us, but forests
nowadays around the world are under threat from deforestation, damaging these
benefits. There are many forms of deforestation. For example, clear-cutting for
agriculture, ranching and development, logging for timber, and natural
degradation due to the change of climate. This brings impact to the livelihood
of the people and endanger wide range of plant and animal species. 18.7 million
acres of forests is losing annually, equivalent to 27 football field every
minute.

Forests play a important role in changing climate
because they act as a carbon sink- soaking up carbon dioxide that would
otherwise be free in the atmosphere and then changes in climate patterns.
Deforestation disturb this important carbon sink function. It is estimated that
15% of greenhouse gas emissions are because of deforestation.

Deforestation is a concern in tropical rainforests
because the forest is home for the the world’s biodiversity. For instance, in
the Amazon almost 17% of the forest has been disappear in the last 50 years,
mostly is caused by the conversion of forest to cattle ranching.

WWF has been working to protect forests for more than
50 years. WWF works with governments, companies, communities with a focus on
protected areas management and sustainable forestry to promote certification
for responsible forest management practices, deny illegal logging, reform trade
and protect forested areas.

 

 

 

 

 

Causes
of deforestation

As stated above, our Earth’s forests are under
threat.  27 football fields of forests
are destroyed every minute. We will lose about 135 species of animal, plants
and insects with each forest is clearing a day.

Forests gives us many benefits, including good such as
paper and timber. Next, they help mitigate climate change by consuming the
carbon dioxide we release into the air, then breathing out oxygen which is
needed to us. Tropical rainforests, such as Amazon, play a vital role in the
water cycle by providing rain to the certain area.

Eighty percent of land-dwelling species creates homes
in forests and the biodiversity ensures global food security and helps poverty
during times of crisis. Question, why are we still destroying our Earth’s
forest?

There is no single factor that is responsible for
deforestation. Instead, it is a combination of forces that are destroying it.
There are some factors:

1.     Agricultural
expansion: The conversion of agricultural plantations form forests is a major
cause of deforestation. The increase in global demand for commercial, such as
palm oil and soybeans, are driving industrial- scale producers to clear forests
at an alarming rate. The largest producer country of palm is Indonesia, was
given a nickname ‘Fastest Forest Destroyer’, in the 2008 Guinness World
Records.

2.     Logging:
Logging is a driver of deforestation, including illegal logging. In Indonesia,
illegal logging operations provide short-term income fore people living on less
than 1 dollar a day. By the way, it destroys the livelihoods of those who
depend on the forest. 80% of timber is being exported illegally in Indonesia,
which is one of the largest exporters of timber. From illegal logging, the
criminals manage to get between $10-15 billion dollars per year.

3.     Infrastructure
Expansion: The construction of road can lead to deforestation by providing an
entryway to previously remote land. The Interoceanic Highway, runs from Brazil
to Peru, long 5404 km, is a concern for conservationists as the road cuts a
strip through the biodiverse Amazon rainforest. The road expansions usually
lead to logging as well as illegal logging, where opportunists slash down trees
without permission from authorities. The cleared land then attracts an influx
of settlers and disrupt the peace of the small villages.

4.     Overpopulation:
In prehistory, we are estimated that our planet can housed maximum 15 million
people. It now has come to 7 billion and still counting. With overpopulation,
there is an increase in global needs and wants, leading devastated at an even
rate with population growth

Example

The serious example of deforestation, we can see the
example of the Amazon Rainforest in South America. Twenty percent of it has
been lost over the last forty years. This is due do the source of timber, trees
are cut down and make room for cattle and soy farms.

The island of Borneo in Indonesia has also experienced
fast deforestation. The deforestation of rate was high during 1980-90s. The
trees at the forest are removed for timber and make room for the palm oil
industry

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Effects
of deforestation

Deforestation will bring the negative impact on the
environment. The most drastic impact is the loss of habitat for millions of
species. Most of the Earth’s land animals and plants live in forests, and many
cannot survive without the forest.

Secondly, deforestation also triggered climate change.
Without the protection from sun-blocking tree cover, the forest soils which is
usually moist and quickly dry out. Trees also help the role of water cycle by
returning water vapor to the atmosphere. Without trees to fill these roles,
many forest lands can rapidly come barren deserts.

Thirdly, trees also play a vital role in absorbing the
greenhouse gases that fuel global warming. Less forests means larger amount of
greenhouse gases entering the atmosphere, and thus increased speed and severity
of global warming.

Conclusion, the deforestation must carefully managed
and the clear-cutting should be eliminating to make sure forest environments
remain intact. The cutting that does occur should be balanced back by planting
young trees to replace older trees that has been chopped off so that it still
maintaining the balance of forest land.

 

 

 

 

 

 

 

 

 

 

 

 

Ozone
depletion

Introduction

What is ozone layer? The earth’s atmosphere is
composed of many layers, each one playing a significant role. The first layer,
known as troposphere, stretching approximately 10 km upwards from the Earth’s
surface. Lots of human activities such as gas balloons, climbing, as well as
aircraft flights take place in this region.

After the troposphere is the stratosphere layer,
approximately 15 to 60 kilometres. The ozone layer is place at the lower region
of the stratosphere from about 20-30 kilometres above the surface of the earth.
The thickness of the ozone layer is only about 3 to 5 millimetres, but it very
fluctuated depending on the season and geography.

Ozone layer is a deep layer in earth’s atmosphere. It
contains ozone which is a naturally occurring molecule that contain three
oxygen atoms(O3). These ozone molecules form a gaseous layer in the Earth’s
upper atmosphere called the stratosphere. In this lower region of stratosphere,
it contains high concentration of ozone called Ozonosphere. The Ozonosphere is
found 15-35 km above the surface of the Earth.

Under 10 parts per million is usually the
concentration of ozone in the ozone layer while the average concentration of
ozone in the atmosphere is about 0.3 parts per million. The thickness of the
ozone layer differs by geography and season. Which mean at certain area and
certain season, the concentration may differ from normal. The highest
concentration of ozone occurs at altitudes from 26 to 28 km in the tropics and
from 12 to 20km towards the poles.

The ozone layer forms a thick layer in stratosphere,
around the earth, has huge amount of ozone in it. Strong ultraviolet radiation
that comes from the sun will not easily harm the life on the earth. Ultraviolet
rays are harmful that can increase the risk of disease like skin cancer,
cataracts and damage the immune system of the life in the Earth.

In 1913, French physicists Charles Fabry and Henri
Buisson discovered the ozone layer. The ozone layer has the capability to
absorb almost 100% of the ultraviolet radiations that sun emit and which can
produce last long devastating effects on human beings as well as plants and
animals.

 

 

How
ozone layer depletion occurs

The cause of ozone layer depletion is human activity,
or more specific, human-made chemical that contain chlorine or bromine. These
chemicals are usually known as Ozone-Depleting Substances(ODS).

Ozone-Depleting Substance have been proven to be
eco-friendly, which mean very stable and non-toxic in the atmosphere. This is
why ODS have increase their amount over the years. However, their stability
only comes to a certain value. When they float up in the stratosphere, ODS are
broken down by the strong UV light and chlorine and bromine are the resultant
chemical particle. Chlorine and bromine are known to deplete the ozone layer at
high speed.  One chlorine molecule has
the ability to break down thousands of ozone molecules.

ODS will stay in the atmosphere for many years.  It is believe that the ODS that human have
allowed to go into the atmosphere for the previous 90 years are still on the
atmosphere until now, which is why they will contribute to ozone depletion.

The major ODS include chlorofluorocarbon(CFCs), carbon
tetrachloride, hydrochlorofluorocarbon(HCFCs) and methyl chloroform. Brominated
fluorocarbons, sometimes known as halons, also contribute to ozone depletion.
However, their application is largely restricted since they are utilized in
specific fire extinguishers.

Scientists in this century, doing experiment to
develop hydrofluorocarbons (HFCs) to take the place of hydrochlorofluorocarbons
(HCFCs) and chlorofluorocarbons (CFCs) for use in vehicle air conditioning.
Compared to above both, HFCs is a better alternative way

There are 2 regions in which the ozone layer has
depleted.  One is in the mid-latitude.
For instance, Australia, ozone layer is thinned. This lead to an increase in
the UV radiation reaching the earth. Another region is in the atmospheric
regions over Antarctica, ozone layer is drastically thinned, especially in
spring season. This has led to the formation of ozone hole.

There are 2 main factors that cause the depletion of
ozone layer, one is the natural causes of depletion of ozone layer and another
is man-made causes of depletion of ozone layer. For natural causes, it is
believed that the volcanic eruptions have contributed towards ozone depletion.

While for man-made causes, the main cause for the
depletion of ozone is show as excessive release of chlorine and bromine from
man-made compounds such as CFCs. The ODS are found to have direct impact on the
depletion of the ozone layer.  The
chlorine and bromine free radicals will react with ozone molecule by substitute
one of the oxygen atom and thus depleting the ozone layer. It is very difficult
to believed but it is a fact,1 chlorine atom can break more than 100000
molecules of ozone. Bromine atom is even has the destructive power 40 times
than chlorine molecules.

Effect
of ozone depletion

1. Human health will be damage

The strong UV light will penetrate directly to the
earth and humans will be over exposed to it. Overexposure to strong UV light
will cause skin cancer, sunburns, quick aging and so on.

2. Devastation to environment

Overexposure to UV light will lead many crops to
minimal growth, photosynthesis and flowering.

3. Marine life will be threatened

Many marine life, especially planktons, is greatly
impacted by exposure to strong ultraviolet rays. If planktons decrease in
number , the marine food chain will be disrupted in many ways due to planktons
appear high in the aquatic food chain. Certain species of marine life have been
greatly affected by overexposure to ultraviolet radiation at their early stage

 

 

 

 

 

 

 

 

 

 

Ways
to reduce the thinning of the ozone layer

1. Avoiding Ozone-Depleting Products

Check the fire extinguishers to find the active
ingredients. If find ODS is the main ingredient, find a hazardous waste centre
to recycle it or call the local fire department for the instruction on how to
dispose it. Replace it with a model without ODS

Don’t buy aerosol products with CFCs and dispose the
old refrigerators, freezers and air conditioning units. These old devices use
CFC to function, it may leak and released to atmosphere

2. Changing habits to protect the ozone layer

First, must drive less. Nitrous oxide is now the
biggest ODS in human activities. So, we must reduce the production of nitrogen
oxide. Car-pooling, public transport, walking and biking is a good way to
reduce driving. Eat less meat can also reduce nitrous oxide being produced.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Global
warming

Introduction

Global warming, usually is the term to describe a
slowly increase in the average temperature of the Earth’s atmosphere and oceans.
This change is believed that it is a permanently changing the Earth’s climate.

Whether the global warming is real or not, always is a
great debate among many people, or even sometimes in the news. However, the
climate scientists agree that the planet is warming by looking at the data and
facts. The scientific consensus on climatic changes related to global warming
is that the average temperature of the Earth has risen between 0.4 and 0.8 degree
celcious over the past 100 years and the effects of global warming is more serious
and more rapidly occur than others do. The main sources of the global warming
that has occurred over the past 50 years are believed is the increased volumes
of carbon dioxide, greenhouse gases released by the burning of fossil fuels, land
clearing, agriculture, and other human activities. A research is carrying out
by the scientists from the Intergovernmental Panel has predicted that average global
temperatures could increase between 1.4 and 5.8 degree celcious by the year
2100. The global warming may result the rising of the sea levels due to the melting
of the polar ice caps, as well as an increase in occurrence and severity of
storms and other severe weather events.