Q.What is Ozone hole ?

The ozone hole is a large seasonal area of severe stratospheric ozone depletion, mainly over Antarctica, caused by CFCs and other ozone-depleting substances, which allows increased harmful UV radiation to reach the Earth's surface.

The stratospheric ozone layer normally absorbs most of the sun's harmful ultraviolet (UV-B) radiation, shielding life on Earth's surface. Since the 1970s-80s, scientists have documented a dramatic, seasonal thinning of this layer, most severely over Antarctica, where ozone concentration can fall by 60% or more during the Southern Hemisphere spring (August-October) -- this region of severe depletion is popularly called the ozone hole. The principal cause is anthropogenic (human-caused) release of ozone-depleting substances, chiefly chlorofluorocarbons (CFCs), historically widely used as refrigerants, in aerosol propellants, and as foam-blowing agents. When these stable compounds eventually drift up into the stratosphere, intense UV radiation breaks them down and releases free chlorine atoms, which then act as catalysts in a repeating chain reaction that destroys thousands of ozone molecules each, without the chlorine itself being consumed. The consequence of this depletion is that significantly more harmful UV-B radiation reaches the Earth's surface, increasing …