What is the Greenhouse Effect?

Many scientists believe that deforestation is causing the earth to become warmer. This is because of what is called the greenhouse effect. The greenhouse effect works like this: The sun's rays pass down through the atmosphere and warm the surface of the earth. The surface throws some of the heat back toward space. However, much of that heat does not escape into space. Gases in the atmosphere called greenhouse gases trap it. This happens the same way a glass garden greenhouse traps heat to grow plants in the winter. The main greenhouse gases are carbon dioxide, methane, nitrous oxide and chlorofluorocarbons (["klɔːrə"flυərəυ'kɒːbən] CFCs).
People have been putting more and more greenhouse gases into the atmosphere, especially in the past hundred years. Many scientists believe this increase in greenhouse gases will slowly cause the earth to become warmer. This is called global warming. Many scientists also believe that global warming could cause the polar ice caps to melt. This may cause flooding of low-lying coastal lands. A rise in temperature could be enough to endanger the crops we need for food. It could also dry up the lakes and rivers in some areas that provide water to crops, towns and cities.

The smoke from cigarettes also contains greenhouse gases. Cigarette smoke contains carbon dioxide and methane. Smoking worldwide releases about 2.6 billion kilograms of carbon dioxide in the air every year. It also releases about 5.2 billion kilograms of methane every year. Tobacco growing, curing, and smoking all add to the greenhouse effect and global warming. scienceu.fsu.edu/content/tobaccoyou/enviroment/docs/globalwarming.html

The term greenhouse is used in conjunction with the phenomenon known as the greenhouse effect.
· Energy from the sun drives the earth’s weather and climate, and heats the earth’s surface;
· In turn, the earth radiates energy back into space;
· Some atmospheric gases (water vapor, carbon dioxide, and other gases) trap some of the outgoing energy, retaining heat somewhat like the glass panels of a greenhouse;
· These gases are therefore known as greenhouse gases;
· The greenhouse effect is the rise in temperature on Earth as certain gases in the atmosphere trap energy.

Six main gases considered to be contributing to global climate change are carbon dioxide (CO2), methane (CH4) (which is 20 times as potent a greenhouse gas as carbon dioxide) and nitrous oxide (N2O), plus three fluorinated industrial gases: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). Water vapor is also considered a greenhouse gas.

Many of these greenhouse gases are actually life-enabling, for without them, heat would escape back into space and the Earth’s average temperature would be a lot colder. However, if the greenhouse effect becomes stronger, then more heat gets trapped than needed, and the Earth might become less habitable for humans, plants and animals.

Kyoto Protocol
An international agreement that aims to reduce carbon dioxide emissions and the presence of greenhouse gases. Countries that ratify the Kyoto Protocol are assigned maximum carbon emission levels and can participate in carbon credit trading. Emitting more than the assigned limit will cause the violating country to be penalized by lowering its emission limitation in the following period. http://www.answers.com/topic/kyoto-protocol?cat=biz-fin