The Ozone Hole
The ozone hole is not technically a “hole” where no ozone is present, but is actually a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August–October). Ozone readings are about 100 DU’s in the Antarctic, or about 1mm thick if compressed (about the thickness of a dime). Historical records show that no ozone readings have even been below 220 DU’s prior to 1979. Ozone depletion has proven to be a direct result from human-released gases like chlorofluorocarbons, or CFC’s, that were commonly used as a propellant and in refrigeration.