The ozone layer is a region of concentration of the ozone (O3) molecule in the Earth's atmosphere. The layer sits at an altitude of about 10 to 50 kilometers, with a maximum concentration in the stratosphere at an altitude of approximately 25 kilometers. In recent years, scientists have measured a seasonal thinning of the ozone layer primarily at the South Pole. This phenomenon is being called the ozone hole. The ozone layer naturally shields Earth's life from the …showed first 75 words of 321 total…

…showed last 75 words of 321 total…deg; North - 65° South since 1978. A reduction of about 3 % per year has been measured for Antarctica where most of the ozone loss is occurring globally. During the late 1990s, large losses of ozone were recorded above Antarctica year after year in the months of September and August. In some years, spring levels of stratospheric ozone were more than 50 % lower than the levels recorded months prior to the seasonal development of the hole.