Environmental Science

This essay has a total of 4555 words and 21 pages.

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. Every

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