FREE ESSAY ON ENVIRONMENTAL SCIENCE

ENVIRONMENTAL SCIENCE

Global Warming
Human kind has entered a brand new relationship with the earth. The constant and
increasing pressures we are exerting threaten our planets ability to sustain life itself.
Change-in the way we think , and in the way we live-is needed now.
Global warming is the most urgent environmental problem the world will face in the next
decade and the next century. Few, if any, trends are more important to our future than
climate change caused by human activities. Scientist around the world are warning us that
global warming poses a major threat to our future quality of life, previously there has
been little information on this problem. Right now, the rate of global warming may be 100
times faster than it has ever been. Very soon the earth may become hotter then at any
time in human history. In the last decades the problems of atmospheric change have been
gravely
advanced by pollution resulting from human activities. These environmental changes pose a
real threat to the lives of people and wild life.
It is vital to all of us that we fully understand the complex relationship between the
atmosphere and the earth.
The earth is getting warmer. the changes are small, so far, but they are expected to grow
and speed up. Within the next 50 to 100 years, the earth will continue to heat up hotter
than it has been in the past million years.
as oceans warm and glaciers melt, land and cities along coasts may be flooded. Heat and
drought may cause forests to die and food crops to fail. Global warming will effect
weather everywhere, plants and animals everywhere and people everywhere.
Humans are warming the earth's atmosphere by burning fuels, cutting down forests, and by
taking part in other activities that release certain heat- trapping gasses into the air.
Humans all over the world need to get together and solve these problems.
In the southern hemisphere, the warming is the greatest over Australia, southern south
Africa, the southern tip of south America, and the area of Antarctica near Australia. In
the northern hemisphere, warming is strongest in Alaska, northwest and eastern Canada,
most of the Soviet Union, and parts of Southern Asia, North Africa and south west Europe.
Climate has cooled in Great Britain and northern and eastern Europe. In the USA
scientists found no overall warming trend in weather records kept since the nineteenth
century, however keepin mind the United States covers only 1.5 percent of the earth's
surface. As warming continues, every place on the earth will be effected.
In the frozen heart of the last ice age, 18,000 years ago, the temperature was only about
nine degrees Fahrenheit colder then today. So a change of a few degrees can have a
dramatic effects. Todays most sophisticated climatic models estimate the global
temperature will rise between 3 and 9 degrees Fahrenheit in the next century.
This could occur as early as the year 2050. Here are the large scale changes the rise
might bring: As water warms it expands, taking up more space. So warmer ocean water, with
added melt-water from glaciers, will rise by twenty inches to five feet in the next 50 to
100 years.
Just a 1 foot rise in sea level can cause shorelines to recede a hundred feet, and in
flat terrain, a thousand feet. If ocean waters rise several feet, whole beaches could
wash away. Many homes, hotels, other buildings, and entire cities will be threatened.
Salt water will pollute freshwater wells that millions of people use for drinking water.
Coastal marshes, which are vital nurseries for fish and other ocean life will be
endangered. Along undeveloped coast, marshes may survive because they can move inland
with the rising waters. In many places seawalls and other human structures will prevent
this process and the marshes will be destroyed.
In the United States ocean water may cover the Florida Keys and large parts of southern
Florida and Louisiana.
Two kinds of action are called for. One is to take steps to prepare for the the effects
of warming that already have begun. Agricultural scientist must develop varieties of
wheat and other crops that can grow in a longer but drier growing season. 
Ways must be fond to use irrigation water more effectively. Conservation will also be
important for drinking water supplies.
Governments that control building and other development along coasts must begin to plan
for rising sea levels. In the United States, billions of dollars have been spent to
replace send eroded from beaches, and to help ownersof beach front homes rebuild after
storm damage. The states of Maine and North Carolina now prohibit permanent buildings on
threatened beaches.
PROFIT OR ENVIRONMENT?
The petroleum industry is no different than any other business. It exist to make money
and will pursue any means to profit. Americans and other people of the world don't
realize how much of an impact the petroleum industry has on the world economy. Most of us
don't think twice or even once at the gas pump about where our money is going. We just
grumble occasionally about the price, then pay and drive off until the tank hits empty,
requiring us to return. For the past century the petroleum industry and the automobile
industry have grown almost as one, industry dependent on each other in the pursuit of
profits. 
According to Ecarta 97, Petroleum has been in use by man for centuries in the form of
lubricants and medicinal products. The past century has seen an explosion of petroleum
exploration to feed the combustion engine. The combustion engine is mainly used in the
transportation industry, primarily automobiles. This century old technology has grown to
the point where the world is dependent on the engine in daily living. 
Why does the world continue to hang on to such old technology that is destroying our
world? The petroleum industry and automobile industry for years have believed that the
worlds oil reserves would never run out. Only during the past few decades have the worlds
industrial leaders realized that the world's supply of petroleum is limited and that it
is having an impact on the environment. 
Although environmentalist with Environmental Protection Agency(EPA) have recognized the
problem, they have been slow to get strict standards passed through legislation. The EPA
has helped by mandating more efficient cars that use less fuel and produce less
pollution. The EPA and other agencies pushing for recycling petroleum products and
cleaner fuel have also temporally slowed the effects of future shortages and pollution.
But, we still haven't solved the main problem: What can we use as an alternate power
source that wont pollute the world?
The industry doesn't want to solve the problem. People are making billions of dollars
every year selling petroleum products that feed our transportation industry. Everything
from gasoline, lubricants, paints and plastics are made from petroleum, and are used in
our automobiles. In 1980 over 114 million automobiles were reported to be on the road
according to governmentstatistics. Consumers continue to demand better and faster
automobiles giving the industry more of an excuse not to change and ignore the problem.
Rumors over the years have reported that the petroleum industry has kept new innovative
products off the market that could help reduce our problems considerably. They do this by
buying the copy rights or paying people not to produce the products. This can be easily
done by an industry that carries a big wallet.
Advertising has also kept the industry going. Advertisers portray a different picture
that gets your mind off the problem. Petroleum companies play on your automotive desires,
like gasoline that performs well and gives you more power. They also play on the
convenience of their stores by selling unrelated products such as groceries. The industry
has changed only to meet economic needs. 
The automobile industry has also done little to comply with a growing attitude of change.
With stricter pollution standards hovering over combustion engines, they continue trying
to perfect hundred year old technology. The combustion engine just keeps being refined
enough to be in compliance with law. The fact is that we are still using petroleum
products in an industry that is growing by leaps and bounds all over the world.
The auto and petroleum industries will keep making minor adjustments to address 
problems of pollution and dwindling resources. It wont be enough as long as petroleum 
consumption continues to rise from millions of automobiles put on the road each year. The

advances we make to curb consumption and pollution are offset by automobile industries
desire to 
produce more and profit. These dilemmas will persist as long as the auto and petroleum
industries 
continue making each other money.
Fusion: Our Future's Energy?
Fusion energy seems to be the most promising energy source of the not-too-distant future.
It is safe, it uses an energy supply that is so abundant that it will never run out, it
gives off harmless waste, and it produces energy comparable to the Earth's sun! But are
there any problems with this hopeful energy source?
What is Nuclear Fusion?
To understand fusion, it is a good idea to know about fission. This is the splitting of
the nuclei of atoms into two or more smaller nuclei by bombarding them with neutrons of
low energy. It was discovered in the 1930's in an attempt to make transuranium elements
(elements with atomic numbers greater than Uranium that do not exist in nature). They
discovered that the nucleus of Uranium-235 breaks apart into two smaller nuclei after
absorbing a neutron. This happens because the extra neutron made it unstable. This
produces more neutrons that bombard more Uranium nuclei, causing a chain reaction that
produces an enormous amount of energy.
The problem is the nuclear waste that is produces. It is very radioactive and will not
become stable for a very long time. Such a harmful substance is a great health concern
and needs to be disposed of. Another problem is the energy it needs. It uses an element
that is hard to find and which will eventually run out. Also, the reaction cannot be
easily stopped and if it can't be stopped, a nuclear meltdown can occur. This is a
serious environmental concern.
Fusion is different. It is a process that combines two nuclei into one, releasing an
amount of energy that is far greater than that of fission. In a common type of reaction,
two isotopes of hydrogen, deuterium and tritium fuse together, making helium and a
neutron. A small amount of the mass produced is converted into an enormous burst of
energy.
Difficulty of a fusion reaction
The main difficulty in a fusion reaction is the heat needed for it to occur. A reaction
such as fusion that requires an intense amount of heat is called a thermonuclear
reaction. It commonly takes place in huge machines called tokamaks. It can only occur in
a special form of matter called plasma, a gas made up of free electrons and nuclei. When
this plasma is heated millions of degrees, the nuclei move so fast that they fuse. The
problem is in finding a container that can hold this extremely hot plasma.
This plasma has a tendency to expand and escape from its container. The walls of the
container have to be very cool, or else they will melt. If the plasma touches the walls,
it becomes too cool for the reaction to occur. But how can a container hold the plasma
without touching the plasma? The answer is in devices known as magnetic bottles, which
are twisted into coils. They have a metal wall that is surrounded by a magnet. Electrical
current flows through the magnet, creating a magnetic field on the inside of the walls.
This pushes the plasma away from the walls and toward the center of each coil.
There are problems with this reaction. All the fusion devices built so far use more
energy than they produce! Another problem is the environmental concern. When neutrons
bombard the walls of the reactors, the walls become radioactive. Walls that become less
radioactive will have to be found. 
Why fusion is still half a century away
The money needed to research fusion is getting smaller and after about four decades of
research, the payoff seems to be far from now. The approach does not seem to be in the
right direction. Researchers have put too much emphasis on designing a practical fusion
power plant without really understanding some of the fundamental physics involved. The
experimental reactors have no general research purpose. The fusion researchers will have
to start rethinking their ideas. Research will have to change from a developing a new
energy technology to developing a broader understanding of a fusion reaction.
Alternatives to current reactors
Some people say that the current fusion reactors, such as the Tokamak Fusion Test Reactor
at Princeton University, should be shut down. But others say that these labs have been
very successful. The Princeton reactor can produce 10 million watts of power in bursts of
about a second each, but it relies on external power. These reactions have not yet
reached a point where the power produced in each reaction can be used directly in the
next reaction, allowing the external power to be turned off. The Princeton lab wanted to
build a new machine to replace the current one, but the cost of 1.8 billion dollars and
the unresolved technical issues caused the idea to be rejected. Instead, the current
machines continue to be upgraded. A different reactor called the International
Thermonuclear Experimental Reactor, a next-generation tokamak, has also been proposed and
seems to be a better choice.
Some people say that a new type of reactor, besides the tokamak, should be used. The
Japanese have a design called the Field Reversed Configuration Reactor. Another idea is
to use lasers to trigger fusion in tiny pellets of fusion fuel. 
The goals of fusion
An ideal fusion reactor of the future could use the hydrogen extracted from one gallon of
water to produce the equivalent energy of 300 gallons of gasoline, eliminating the need
for fossil fuels. Everything should be automatic with very little supervision. It should
produce no harmful wastes and have no possibility of failure. But the technical obstacles
involved to make such a device are far from being completed. Fusion will not become a
commercial device until the second half of the next century. However, one thing is
evident: Fusion will eventually be the leading source of energy for the future.
Cloning
Twenty years ago, scientists said that cloning was completely impossible. But now, the
science of cloning 
has come to realization. Imagine meeting an exact replica of somebody. They look alike,
think alike, and 
even have the same genetic makeup. No, this isn't an episode of Star Trek, this is
reality. This is the new 
world of cloning, and thanks to a 7-month-old sheep named Dolly, a new science has been
born. As with 
every new science, there are those who believe in it, and those who oppose it. The new
technology of 
cloning should be utilized because it could bring back extinct organisms, help infertile
couples to have 
children, and potentially save many lives.
Cloning could bring back extinct animals. Over millions of years, thousands of different
species 
have gone extinct. Most were due to natural selection, while several others were due to
human 
intervention. According to the Encarta Encyclopedia, 1997, nearly two-thirds of all the
native bird 
species and one-tenth of the native plants originally found on the Hawaiian Islands have
gone extinct 
recently. Most of these losses have been of species unique to the Hawaiian archipelago.
Predators, 
competitors, or diseases introduced by humans from continental areas are responsible for
many of the 
extinctions. Many remaining species on oceanic islands are threatened or endangered. With
cloning, many 
of the animal species, and potentially several of the plant species could be brought back
to life. Even 
though there is currently no technique for bringing the plants back, with technology
advancing so quickly, 
we could have a solution quite soon. Cloning, though now limited to an!
imal subjects, potentially has significant human applications.
Cloning will help a couple who would normally be unable to have children because one of
them was 
infertile. In the case of an infertile father, scientists take an egg from the mother,
remove its nucleus, then 
take a cell from the father, remove its nucleus, and place the nucleus inside the empty
egg. That cell now 
acts as a reproductive cell. They then put the egg in the mothers' womb, and wait for
results. 
Unfortunately, this method has a very low success rate. According to Gina Kolata of the
New York Times, 
February 23, 1997, in the experiments with the sheep, 277 cells were attempted.
Twenty-nine of those 
developed into embryos. When those cells were transferred to the female sheep, only
thirteen became 
pregnant. Of those thirteen, only one carried the pregnancy to full term and delivered a
live lamb. 
However, with the ever-progressing technology, scientists will be able to achieve higher
success rates. The 
power of cloning can not only be used to create life, it !
can also be used to save it.
Cloning has many medical benefits that could be utilized. It could be used to replicate
organs from 
animals that would be suitable for transplant into humans. This process would increase
the amount of 
people who could be saved. Since there would be more organs, the waiting lists for
transplants would 
become much shorter. According to James Glassman or the Denver Post, February26, 1997,
Engineered 
animals like pigs could be cloned and harvested for organs to transplant into sick
humans. This would be 
much easier, because you don't have to wait for an organ donor. Cloning can also recreate
certain 
genetically engineered animals that carry helpful substances. In the case of the sheep,
the main product that 
they are trying to get is AAT, a sheep's milk now in clinical trials for use in treating
cystic fibrosis.(CNN 
on-line, February 23, 1997) Also, according to the Grolier Electronic Encyclopedia, 1992,
clones have 
produced such medically important substances as Insu!
lin, interferon, and growth hormone. 
Due to the overwhelming positive implications, society must embrace this new technology.
The 
science of cloning should be used because it could resurrect extinct animals, give
couples a new hope, and 
medical science now has a new tool that could potentially save thousands of lives.
Cloning, once the stuff 
of science fiction, will with recent advances become an integral part of our society.
To What Extent Does Acid Precipitation Affect Annelids?
In order to truly understand acid rain and it's eventual effect on
earthworms, it would be best to look at the causes of acid rain. How and
why does altered acidity in precipitation have a devastating effect?
Acid rain is charecterized as Precipitation that has a pH lower than about
5.0 (Allaby, Michael (1994) Ecology, Oxford Press,). Acid rain is created
by many things, of which pollution from cars contributes the most. Ever
since the Industrial revolution, the acidity of rain has been haywire.
Sulfur and nitrogen are found widely throughout the world in the air, even
in unindustrialized tropics (Graedel, Thomas, et. al, (1989, V261 n3 p.
58-68 Sep. 1989) The Changing Atmosphere, Scientific American).
The way in which acid rain is created from here is that About 70 percent
of acid rain comes from sulphur dioxide (SO2), which dissolves into the
water to form sulphuric acid. The rest comes from various oxides of nitrogen
(mainly NO2 and NO3, collectively called NOx). These gases are produced
almost entirely from burning fossil fuels, mainly in power satations and
road transport. (Kucera, (1973) The Challenge of Ecology, The Mosby
Company.) 
Tremendous quantities of this nitric acid and sulfuric acid mix are
reflected in the lowering of the acidity of rain.
Earthworms (Annelids) are a species of worm which are many segmented. They
live in damp soil, usually forming intricate tunnels beneath the surface.
Their bodies are lond and cylindrical, and have bluntly tapered ends and
are somewhat depressed posteriorly. (Storer, et. al, (1972) General Zoology
5th ed., McGraw Hill Books.) As earthworms burrow, thew swallow large
quantities of earth that often contain large amounts of vegetable remains,
often depositing, or casting, their very nutritive remains to the soil,
which adds to it's enrichment. The first person to truly recognize the
importance of earthworms was Gilbert White, when he wrote in his book, The
Natural History of Selbourne (1788) that soil was loosened, aerated, and
made more fertile by earthworms. (Gilber White (1788) The Natural History
of Selbourne)
Earthworms are typically very sensitive to low pH levels. Therefore, it
isn't surprising that pH of soil is sometimes a factor that limits
distribution, numbers, and species of earthworms. (Edwards and Lofty
(1977), Biology of Earthworms, Chapman and Hall)
There have been many experiments done on this, which indicate that
earthworms prefer soils with a pH of about 7.0. Some improtant workers
include Arrhenius in 1921, Moore in 1922, Phillips in 1923, and Petrov in
1946. All these studies concluded the above stated fact, that worms prefer
7.0 However, in Denmark, Bornebusch found Dendrobaena octaedra, which is
an acid-tolerant species (Bornebusch, 1930) Studies have also been
conducted in Egypt, where it was found by El-Duweini and Ghabbour that soil
can also be too alkaline to favour earthworms (El-Duweini and Ghabbour, 1956).
In a study done by Satchell in 1955, in which earthworms were placed in
plots of soil with pH values ranging from 4-7, the worms in soils with the
higher acidities were jerking and convulsing........after 1 to 2 hours
became motionless and flaccid. After 24 hours, fifty-eight out of sixty
worms exposed to pH below 4.4 were dead. (Edwards and Lofty, (1977) Biology
of Earthworms, Chapman and Hall) Earthworms are easily used for
experimentation by researchers because they are widely distributed,
familiar organisms, which are readily and cheaply available in large
numbers. (Pierce, et. al, (Sep, 1988 Volume 70) Science Notes, School
Science Review.) 
In soils of pH less than 5, earthworms are usually scarce, and soil
breakdown is usually slow, making a deep layer of slowly decomposing plant
remains. (Pierce, et. al, (Sep, 1988 Volume 70) Science Notes, School
Science Review.) This is a very obvious sign of wether or not earthworms
are present, and more often than not, the pH range can be determined on
sight. If you look through soil and see plant material broken down and
mixed through the soil, you know that earthworms are there and are playing a
major role in soil breakdown and nutrition.
The Greenhouse Effect
The greenhouse effect is an increase in the atmospheric temperature caused
by increasing amounts of greenhouse gases. These gases act as a heat blanket
insulating the Earth's surface absorbing and trapping heat radiation which normally
escapes from the earth. They include carbon dioxide, water vapor, methane,
nitrous oxide, CFC's, and other halocarbons.
The earth's atmosphere goes through two processes constantly. Global cooling
is the first process. This process uses the clouds which cover 60% of the earth's
surface to reflect 30% of the solar radiation. It also uses a sulfate haze, which
is formed by sulfur dioxide from industrial sources that enter the atmosphere and
react with compounds to form a high-level aerosol. These cool the atmosphere by
blocking us from direct contact with the sun. The reflection of the sunlight is
referred to as planetary albedo and contributes to the overall cooling.
The second is the warming process. This is when light energy comes through
the atmosphere and is absorbed by Earth and transformed to heat energy at the
planet's surface. The infrared heat energy then radiates upward into space. There
the greenhouse gases found naturally in the troposphere absorb some of the infrared
radiation. The gases insulate the Earth, but do eventually allow the heat to
escape. Without these greenhouse gases the earth would be would 33 C colder.
Global temperature is a balance of the effects of the factors leading to
global cooling, and warming. Unfortunately, increased emissions of greenhouse
gases increase the warming process. For example, every kilogram of fossil fuels
burned equals 3 kilograms of carbon dioxide ( the mass triples because each carbon
atom in fuel bond to two oxygen atoms, in the course of burning, and forms C02. )
6 billion tons of fossil fuel carbon are burned each year adding 18 billion tons
of C02 to the atmosphere. This has increase the carbon dioxide concentrations
by 25% and has cause temperatures to increase more than 0.7 C over the last hundred
years.
We hope that the forests will act as a sink for carbon dioxide but instead
they are a net source. This is because the forests are being cut and burned adding
1 to 2 billion tons annually to the 6 billion tons of carbon already from industrial
processes. Fortunately, the top 300 meters of oceans absorb most of the carbon
dioxide emitted by burning fossil fuels.
Other factors are known to increase the greenhouse effect. These factor
are water vapor, methane, nitrous oxide, CFC's and other halocarbons. Water
vapor is also a major factor in what has been called the supergreenhouse effect
in the tropical Pacific ocean. Water vapor traps energy that has been radiated
back to the atmosphere. The high concentration of H2O vapor contributes
significantly to the heating of the ocean surface and lower atmosphere in the
tropical Pacific.
Methane (CH4) is a product of microbial fermentative reactions and is also
emitted from coal mines, gas pipelines, and oil wells. Methane is gradually
destroyed, but it is added to the atmosphere faster than it can be broken down.
Methane (CH4) is a product of microbial fermentative reactions and is also
emitted from coal mines, gas pipelines, and oil wells. Methane is gradually
destroyed, but it is added to the atmosphere faster than it can be broken down.
Nitrous oxide (N2O) can be found in biomass burning, chemical fertilizers,
and fossil fuel burning. Nitrous oxide is more dangerous than some of the others
because of its long residence time of 170 years.
CFC's and other halocarbons are found in refrigerants, solvents, and fire
retardants. Halocarbons have a greater capacity, 10 000 times, for absorbing
infrared radiation, which is about 60% more, than CO2. Although there is increase
in the application of some of these gases, they will decrease in importance in
the future leaving carbon dioxide as the primary dilemma.
In 1981, James Hansen of NASA invented a model with an ability to track
known temperature changes and link them to past and future carbon dioxide levels
as well as global temperature changes. The model suggested the combination of
CO2 and volcanic emissions was responsible for most of the observed changes in
temperature during the 1980's. A trend of warming of more than 0.7 C coincides
with an increase of 25% in carbon dioxide.
Two major impacts of greenhouse effect are regional climatic changes and
a rise in sea levels. A climactic change will lead to variations in temperature.
Scientists expect more precipitation which may prove to be disastrous for North
America by flooding rivers and lakes.
A rise in the sea levels is anticipated because of an increase in thermal
expansion and the melting of ice caps and ice fields. Like extensive rainfalls,
a rise in the ocean will flood lakes and rivers covering land and may someday bury
continents.
In order to control the effects of global warming we must first admit that
it's occurring, then take steps to end it. We must stop burning the trees and
not replacing them. Most importantly, we must stop polluting the air.