What Is the Depletion of Ozone Hole?
In 1996 studies conducted by US National Aeronautics and Space Administration revealed a big hole greater than the total surface area of North America over the continent of Antarctica. This is known as the ozone hole. As a result of this large amount of ultraviolet rays enter the lower atmosphere. If not checked in time the ozone depletion can cause dangerous consequences.
The ozone in the stratosphere absorbs most of the harmful ultraviolet rays from the sun. These rays can otherwise cause skin cancer and damage vegetation, among other things. Exposure to these ultraviolet rays kills bacterias and several microorganisms that are very important for the earth’s ecology.
A depletion of ozone that occurs over Antarctica in the winter returns to normal levels in the summer, and the amount of depletion varies from year to year. The hole is thought to be caused by a combination of the peculiarities of atmospheric circulation near the South Pole and chemical reactions involving chlorofluorocarbons in the atmosphere and ice crystals in clouds.
The depletion of ozone is a human phenomenon. Like air pollution, reducing the levels of pollutants that we emit in the atmosphere, can control it. Most air-conditioners, refrigerators and spray cans contain a substance called CFC (chlorofluorocarbons) that destroys the ozone gas, converting it into other gases.
This is what has caused the ozone hole over a period of time. It is precisely for this reason that worldwide standards for air-conditioning equipments are being modified. A new substance called HFC (hydrofluorocarbons) is being used instead of CFC.