Global Green House Effects Essay, Research Paper
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 vapour, methane,
nitrous oxide, CFC’s, and other halo-carbons.
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 metres 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 vapour, methane, nitrous oxide, CFC’s and other halo-carbons. Water vapour is also a major factor in what has been called the “super-green house effect” in the tropical Pacific ocean. Water vapour traps energy that has been radiated back to the atmosphere. The high concentration of H2O vapour 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.
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 halo-carbons are found in refrigerants, solvents, and fire retardants. Halo-carbons 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.
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 keep in 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 owners of beach front homes rebuild after storm damage. The states of Maine and North Carolina now prohibit permanent buildings on threatened beaches. 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.