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 so

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.

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.

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.

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.

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.

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.

It is vital to all of us that we fully understand the complex relationship between the atmosphere and the earth.

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.

Humans are warming the earth's atmosphere by burning fuels, cutting

Some common words found in the essay are:
Greenhouse Effect, North America, Europe USA, Methane CH4, Hansen NASA, Florida Louisiana, North Carolina, America Antarctica, carbon dioxide, Europe Climate, global warming, North Africa, greenhouse gases, water vapour, nitrous oxide, greenhouse effect, rise sea, earth's surface, ocean water, sea levels, vapour methane nitrous, nitrous oxide cfc's, oxide cfc's halo-carbons, methane nitrous oxide, rise sea levels,
Approximate Word count = 1564
Approximate Pages = 6 (250 words per page double spaced)