Global warming is one of those areas of science that gets all sorts of people exited. Though a few ask for more and more evidence that global environmental change is taking place, most accept that human activities are causing changes quite unlike any. But what exactly is it. Is it natural? Why is it happing? And what is it doing? The planet we inhabit is blessed with some very special conditions that just happen to be perfectly suited to sustain life. Global warming is the increase of average world temperature as a result of what is known as the greenhouse effect. Certain gases in the atmosphere act like glass in a greenhouse, allowing sunlight through to heat the earth`s surface but trapping the heat as it radiate back to space. As the greenhouse gases build up in the atmosphere the earth gets hotter. Organization related to this have quickly realize this and since 1980 have seen a huge research effort to explain the probable effects on our environment. The research continues, as we try to discover what rates of change can be tolerated.