Part 1 of Essay
The importance of the stratospheric ozone layer, which filters out most of the sun's harmful ultraviolet radiation, in protecting the Earth's surface from the harmful effects of solar ultraviolet radiation has been recognized for many decades. It was not until the early 1970s, however, that scientists began to actually g ....

Part 2 of Essay
.... rays and clouds as well as other natural occurring events. The National Weather Service announced that 1998 was the warmest year (on record on average, around the world). A recent tree-ring study indicated that this is the warmest decade in six hundred years (Allen & Herreid, 82). Undeniably, the weather is getting warmer. According to an article in The Economist, a conservative newsmagazine, "The sea is warming, the plankton dying; floods are sweeping the land. In California, the climate is acting in a pecul ....