Environmental Science
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.