I N T R O D U C T I O N
For hundreds of years, climates on earth have gone through great changes. The changes are caused by many activities that have occurred and are presently occurring on earth. Increasing evidence indicates that human impact on the environment is causing local and perhaps worldwide changes in climate.
At various times, glaciers have moved down across the continents into regions that are now warm. This effect of global warming is the meltdown of glaciers of Greenland and Antarctica that could raise sea levels all over the world.
The burning of fossil fuels- coal, natural gas, and oil- are constantly adding carbon dioxide into the air. In addition, industries are producing more chloroflourocarbons (CFCs), nitrous oxide and methane, which are all greenhouse gases (Koral 4).
The resulting warming of the atmosphere, or Global Warming, could have serious effects.
W H A T I S T H E G R E E N H O U S E E F F E C T ?
Similar to a greenhouse, the earth is warmed by the sun. The sunlight striking Earth’s surface is converted into infrared (heat) radiation. Most of this heat will escape back into space, but today much more of it is being trapped in the earth’s atmosphere. Due to the resemblance to the way that heat is trapped in a greenhouse, scientists call this trend toward increasing global warming, the Greenhouse Effect (Koral 9).
Scientists also say that because of the greenhouse effect, our weather may change more in the next decade than in the last tens of thousands of years. They predict that the earth will become hotter. For instance, in some parts of the world, winters will be warmer, while summers will be hotter. As mentioned earlier, another possible result of the greenhouse effect will be that the world’s oceans will rise, probably one to four feet in the next century (Koral 11).
The atmosphere is the “blanket” of air that surrounds the earth and protects us from the sun’s harmful rays. It basically contains nitrogen ( approx. 80%), and oxygen (approx. 20%). There are also small amounts of many other gases, one of these being carbon dioxide (”Climate”).
Carbon dioxide plays a vital role in living things. The amount of it in a planet’s atmosphere also affects the temperature on that planet. Carbon dioxide exists naturally in the atmosphere in minuscule quantities. However, it is also produced every time we burn something that contains carbon (”Greenhouse Effect”).
Carbon is in the category of fossil fuels-coal, oil, and natural gas. Each time we burn a fossil fuel, we add more and more carbon dioxide into the atmosphere. Right now, people of the world are putting more than 5.5 billion tons of carbon, in the form of carbon dioxide gas into the atmosphere every year. As more and more carbon dioxide builds up in the atmosphere, less heat can escape, and the planet gets warmer (”Greenhouse Effect”).
Other gases are also trapping the planet’s heat. These include CFCs, methane, and nitrous oxide. Like carbon dioxide, some of these other greenhouse gases have been in our planet’s atmosphere for a long time (Koral 18).
This extraordinary rise in the quantities of greenhouse gases have tremendously upset the atmosphere’s fragile and delicate balance. The result of this may cause the most serious environmental dilemma this planet has ever faced. How did it all begin?
To run our factories, heat our homes, and run our cars, we need energy. We get most of this energy by burning coal, oil, and gas. Evidently, every time we burn one of this fossil fuels, we release carbon dioxide gas, which only contributes to the greenhouse effect and global warming.
Some scientists have been concerned for a long time about what might happen if there was too much carbon dioxide in the atmosphere. Many scientists even claimed that if the amount of carbon dioxide in the atmosphere doubled, enough infrared radiation would be trapped to increase the average temperature of the earth by several degrees (”Greenhouse Effect”).
It was estimated that since the Industrial Revolution began in the mid-1800s and people began building many factories and burning large amounts of fossil fuels, there has been nearly a 25% increase of carbon dioxide levels in the atmosphere. Scientists find this out by measuring carbon dioxide in the air that became trapped in glaciers (large, slow-moving bodies of ice) hundreds of years ago. Then they compare this to the amounts of carbon dioxide in samples of today’s air (”Greenhouse Effect”).
Up until recent times, approximately half of the carbon dioxide that was produced was absorbed by the world’s oceans and trees. The rest remained in the atmosphere.
Unfortunately, not only are we producing more carbon dioxide, but our world is also absorbing less. This is the result of our planet’s forests being destroyed. Research has been done to show that as much as one hundred acres of the world’s remaining forests are being destroyed, every minute, every day of the year. In the United States, forests are also disappearing due to pollution from coal -burning power plants ( Koral 31).
Carbon dioxide is just one of the gases that is causing the greenhouse effect. Like carbon dioxide, CFCs absorb infrared radiation and make our planet warmer than it is. CFCs are also used to make aerosol spray cans, refrigerants, air conditioners, and to clean electronic equipment (Stille 13).
CFCs have an extremely long lifetime. For example, even after you dispose of a plastic container from a fast-food restaurant, the CFCs do not disappear. They may stay in the atmosphere for as long as three hundred years.
Other dangerous greenhouse gases that trap the earth’s heat are nitrous oxide and methane. They are produced by decaying vegetation, the use of chemical fertilizers, coal mining, and the burning of fossil fuels and wood. Small particles of methane stay in the atmosphere for only about ten years. In contrast, nitrous oxide particles may linger in the atmosphere for up to one hundred and seventy years (Bilger 5).
Although greenhouse gases can have a tremendous effect on our planet, there are only a small part of the atmosphere. However, even a tiny increase in the amount of greenhouse gases in our environment can result in a dramatic change in our climate-and our lives (”Greenhouse Effect”).
THE PROS AND CONS
Scientists predict that our planet will warm up in an average of three degrees Fahrenheit. Others estimate that it will be as much as nine degrees hotter by the year 2030. The range of three to nine degrees may not seem like that much at the moment, but even a 3-degree warming would have a dramatic effect on all the world (Bilger 11).
If the world became hotter, summers similar to the heat wave of 1988 would become typical and might last even longer (Greenhouse Effect”). Thus, more people would suffer.
Another effect of the warming of the planet is that there might be less rain. During such a drought, it would become harder to raise food and crops, and prices for the food would undoubtedly go up. Several states have already witnessed water shortages due to drought. Government in these regions have recently passed laws limiting usage of water (”Climate”).
Scientists also predict that the greenhouse effect will help some plants to grow larger. This is due to the main greenhouse gas, carbon dioxide, that is also a natural fertilizer. Plants that are grown in special laboratories where there is a lot of carbon dioxide in the air, not only grow bigger, but need less water (”Climate”).
As temperatures increase, the world will also change in other ways. Many say that the oceans may rise, by one foot in the next forty years, and two to four feet in the next one hundred years. The reason for this is that ocean water expands and increases in volume as it gets warmer. For example, snow from mountain tops could melt and make the oceans rise even more (”Greenhouse Effect”).
What would happen if the level of the sea rose? Nearly one-third of all human beings live within forty miles of a coastline. In the Untied States and elsewhere , many cities and homes are built near the ocean. These areas could be flooded by the rising waters . Beaches could be covered by water, and some ports and bridges might be destroyed (Koral 33).
Scientists are increasingly concerned about a particularly dangerous effect of the CFCs. This greenhouse gas does more than just contribute to the warming of the planet. Researchers are now indicating that CFCs can harm the earth in other ways (Bilger 14).
In 1987, scientists went on an unusual voyage to investigate a “hole” in the sky over the Antarctic that had earlier been detected by satellites and computers. This “hole” is a section of the sky where the atmosphere seems to be thinning out. The area where this is happening is as large as the United States (Stille 7).
W H A T I S T H E O Z O N E L AYE R ?
The part of the atmosphere this “hole” is in, is called the ozone layer. The ozone layer is a layer of the upper atmosphere lying about twenty to twenty-five kilometers above the earth’s surface. It is named this because the unstable form of oxygen called ozone is concentrated in this layer. The ozone layer strongly absorbs ultraviolet radiation from the sun. If by chance this radiation reached the earth’s surface at unprotected levels, it would be harmful to all forms of life on the earth (Stille 12).
Scientists believe that the ozone layer is slowly being broken down by CFCs. Just one CFC particle can break down tens of thousands of ozone particles.
Although the ozone layer is made up mostly of other gases, it is the ozone that shields us from much of the sun’s ultraviolet rays and prevents them from reaching the surface of the earth. If this ultraviolet radiation reached the earth’s surface, it would raise the incidence of human skin cancers and cataracts, as well as reducing food production. Excess rays may also impair the body’s immune system, which fights disease (Stille 15).
Experts are also concerned about what might happen to plants and animals because of the excessive ultraviolet rays. They fear that the ultraviolet light will hurt phytoplankton, tiny one-celled plants that float near the top of the ocean. In addition, phytoplankton take in a great amount of carbon dioxide. If they no longer resume living, carbon dioxide levels would rise and speed up the global warming process (”Greenhouse Effect”).
Because of the increase in greenhouse gases, the earth may face serious problems. The question now is, how do we solve them? Or better yet, how do we prevent them from happening in the first place?
WHAT ACTIONS CAN WE TAKE?
Some experts say that in order to stop, or even try to slow down the warming of our planet, we must take dramatic action. These actions, however, may be too expensive. Other scientists, though acting as a minority say that we do not need to rush into action. They are wondering whether nature will restore the balance of the world. Perhaps, the oceans will start to absorb more amounts of carbon dioxide, or clouds will form to protect us from the sun’s harmful rays. Finally, there is the group of scientists that say that it may be too late to prevent the greenhouse effect (Koral 36).
Scientists cannot do tests that will try to predict possible future occurrences. They are not able to add more carbon dioxide to the earth’s atmosphere or raise the earth’s temperatures to see how much the oceans will rise.
So, to make a prediction of our future climate, researchers take into account how much oil, coal, and gases likely to be used , how much the population will increase and how many more factories will be producing various items. They can also use information that we already know about our weather, oceans, and rainfall. With this data, the researchers are able to make slight predictions about what the climate of the world will be like in the years to come (Bilger 17).
Most experts agree that in the end some warming of the world will occur. They believe that there is nothing much we can do now to prevent the temperatures from rising any further, but the best we can do is not let it get to dangerously warm and this means that we have to make some sacrifices, to change the way that we are living now. Even if we begin to cut down our levels of greenhouse gases, the result would show in another twenty to thirty years (”Climate”).
For a start we have to find energy sources other than oil, coal, and gas. One very important source of energy is the sun. Throughout the United States, people have been building their houses with solar panels. Several companies and factories have built power plants that are run by the sun’s energy. Perhaps one day, we will be using this as a more permanent alternative. But as of now, it is a very costly one. Other sources of power are- hydropower (electricity from running water), wind power, and possibly in the future, fusion (the way the sun produces energy, by combining atoms) (”Greenhouse Effect”).
Many people also believe that we should be building more power plants. One nuclear plant can provide electricity to hundreds of thousands of homes, while producing absolutely no greenhouse gases. However, there are also dangers in using this kind of power. There is the splitting of atoms to release energy, which will also increase radioactivity (Koral 37).
There is something that we can all do right now to slow down the greenhouse effect. We can start conserving energy. We can also insulate our homes and buildings better so that less heat is needed to warm them, as well as using our air conditioners less. Consumers can buy cars that use less gasoline and the manufacturers of those automobiles must be required to produce and design more energy-efficient cars. People can also use more efficient light bulbs and appliances. Our air conditioners could be designed so that the coolants, which contain CFCs could be removed before they are disposed of , therefore, preventing the CFCs from being released into the atmosphere (Koral 39) .
There are many products that can be made substitutes for CFCs. Some have already been developed and others are being made available.
W H O’S TO BLAME?
Perhaps the wealthiest and most highly developed countries are to blame for it. The United States is at the top of the list for fossil-fuel emissions, at about 25% of the total; Russia and China together contribute about 33%; and the nations of Western Europe and Japan together contribute about 23% (Koral 43).
Most countries agree that to reduce greenhouse gases, we must do much more than just talk to each other and exchange information. We must begin to pass laws to control the production of these harmful gases.
The greenhouse gases are often the by-products of the things that make our lives easier. They come from energy plants that produce electricity and from car and clothing factories. Poorer nations of the world are some what eager to build power plants and produce more items for their people. They do not believe that it is fair for the richer countries of the world, who they believe are largely responsible for the greenhouse effect, should tell them what they can and cannot do (Bilger 21).
C O N C L U S I O N
No matter what steps we take for prevention there will probably always be some global warming. “In environmental science, the greenhouse effect is a popular term for the role that the variable atmospheric constituents carbon dioxide, water vapor, and trace gases play in keeping the earth’s surface warmer than it would be without their presence” (”Greenhouse Effect”).
Climatic changes including flooding and droughts as well as health problems are just a few of the many, many results of global warming. We as a nation must strive and work together to shape the fate of our living earth.
Global warming and the greenhouse effect are problems that need serious and critical attention. Even though the problems may be more severe in one region than another in the end it will affect and harm all of us in the end.