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"What Is Global Warming?"

Global warming refers to the increased temperature of Earth's surface, including land, water and near-surface air.

Per most of the scientific community, Earth has warmed significantly since the mid-20th century due to an increase in greenhouse gases that trap heat on Earth.

The Causes of Global Warming

Global warming is caused by excessive quantities of greenhouse gases emitted into Earth's near-surface atmosphere. Greenhouse gases are both man-made and occur naturally, and include a number of gases, including:

* carbon dioxide

* methane

* nitrous oxide

* chlorofluorocarbon

water vapor

Optimal amounts of naturally occurring greenhouse gases, especially water vapor, are necessary to maintain the Earth's temperature at inhabitable levels. Without greenhouse gases, Earth's temperature would be too cold for human and most other life.

However, excessive greenhouse gases cause Earth's temperature to warm considerably which cause major, and occasionally catastrophic, changes to weather and wind patterns, and the severity and frequency of various types of storms.

reenhouse Gases Generated by Mankind

The scientific community as a whole has concluded that naturally occurring greenhouse gases have remained fairly constant over the past several hundred years.

Greenhouse gases directly and indirectly generated by mankind, though, have increased radically for the past 150 years, and especially in the past 60 years.

Major sources of greenhouse gases generated by mankind are:

* Burning of fossil fuels, which includes oil and gas, coal and natural gas.

* Chlorofluorocarbons, commonly used in refrigeration, cooling and manufacturing applications.

* Methane, which is caused by emissions from landfills, livestock, rice farming (which uses methane-emitting bacteria), septic processes, and fertilizers.

* Deforestation

Per Rainforests.com, "The largest (manmade)contributor to the greenhouse effect is carbon dioxide...