The Big Picture 

:General background on Global Warming


Here we'll talk about the central background issues behind global warming: the science, the politics and what the major parties are that involved in the debate and process of implementing policy changes that will reduce emissions.

"According to the Intergovernmental Panel on Climate Change, a panel of scientists convened by the United Nations’ Environment Program and World Meteorological Organization, the Earth will warm 2 to 6 degrees Fahrenheit by the year 2100, with a best estimate of about 4 degrees Fahrenheit." (EPA)

:What is the Greenhouse Effect? 

The ultimate source of energy driving the Earth’s climate is the sun. Sunlight warms the
Earth’s surface, which responds by re-emitting energy in the form of infrared radiation (heat).
If the Earth had no atmosphere, the sun would warm the surface to only about –18 degrees
Celsius (°C; or about 0 degrees Fahrenheit (°F)), a temperature well below the freezing point
of water and probably unable to support life. But observations show that the average surface
temperature is actually about 15 °C (59 °F). This 33 °C (59 °F) difference is due to a natural
atmospheric phenomenon known as the greenhouse effect.

The greenhouse effect results from a number of gases in the atmosphere that are transparent
to incoming sunlight but absorb the heat emitted from the Earth’s surface and reradiate it in all
directions, including back toward the surface. As a result, the surface is warmed more than it
would have been in the absence of these gases, which serve a purpose similar to that of the
glass walls of a greenhouse. The greenhouse effect forms the backbone of current
understanding of the Earth’s climatic history, as well as the understanding of climates of other
planets such as Venus and Mars.

                                                                                                                    (courtesy of EPA)



*Global Change             Online Journal on climate Change and Ozone Depletion

*N.Y.Times Global Warming Archive

[Common Misconceptions] courtesy of EPA (PDF format)

Home ] Greenhouse Gases ] Human Activity ] Projections ] Int'l Climate Politics ] Links: ]