Discovery of a new ozone hole over the tropics

Tags: Science and Technology

According to a recent study, a new ozone hole has been detected in tropical regions from 30 degree south latitude to 30 degree north latitude.

Facts from the study 

• The tropical ozone hole is about seven times larger than that of the Antarctic.

• The tropical ozone hole is visible in all seasons, while the ozone hole over the Antarctic is visible only in spring.

• Scientists estimate that it is so large that it can affect 50 percent of the world's population.

• According to scientists, this hole has been present in the tropical region since 1980.

• Like the Antarctic ozone hole, ozone values in the centre of this tropical ozone hole have been found to be 80 percent below normal.

• This has the potential to cause skin cancer, cataracts and other negative effects on the health ecosystem in tropical regions.

Ozone layer

• It is a special form of oxygen that has the chemical formula O3.

• Most of the ozone lies 10 to 40 km above the Earth's surface. Lives at high levels in the atmosphere between This region is called the stratosphere and contains about 90% of the total ozone found in the atmosphere.

Classification

Good Ozone

• Ozone occurs naturally in Earth's upper atmosphere (stratosphere) where it forms a protective layer. This layer protects us from the harmful ultraviolet rays of the sun.

• This ozone is slowly being destroyed due to man-made chemicals called ozone depleting substances (ODS). Ozone depleting substances include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, and methyl chloroform.

Bad Ozone

• Ozone is formed in Earth's lower atmosphere (troposphere) near ground level when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight.

• Surface level ozone is a harmful air pollutant.

Initiatives taken to protect the ozone layer

Vienna Convention

• The 1985 Vienna Convention for the Protection of the Ozone Layer was an international agreement in which the members of the United Nations recognized the fundamental importance of preventing the depletion of the ozone layer of the stratosphere.

• India became a party to the Vienna Convention for the Protection of the Ozone Layer on 18 March 1991.

Montreal Protocol

• The Montreal Protocol is an international environmental agreement to protect the Earth's ozone layer by eliminating the use of ozone-depleting substances.

• Adopted on September 15, 1987, this protocol is the only United Nations treaty to date that has been ratified by all 197 member states of the United Nations by every country on earth.

• India became a party to the Montreal Protocol on 19 June 1992 on substances that damage the ozone layer.