Thursday 16 September 2010

ALL ABOUT OZONE


“When we heal the earth, we heal ourselves.” - David Orr

Today is the International Day for the Preservation of the Ozone Layer, as declared by the United Nations (UN). The day commemorates the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer on September 16th in 1987. The meeting of representatives from 24 countries in 1987 had a conference and announced to the world that it was time to stop destroying the ozone layer. In so doing, these countries committed themselves, via the Montreal Protocol on Substances that Deplete the Ozone Layer, to rid the world of substances, such as fluorocarbons, that threaten the ozone layer. On December 19, 1994, the UN General Assembly proclaimed September 16th to be the International Day for the Preservation of the Ozone Layer. The day was first celebrated on September 16, 1995.

The earth’s ozone layer plays an important role in protecting human health and the environment. In 1974, U.S.A chemists Sherwood Rowland and Mario Molina were the first to sound the alarm about ozone layer depletion. That year, they published the first scientific article predicting the near disappearance of the ozone layer in 75 years. They were remarkably accurate; in the early 1980s, a hole in the ozone layer was observed for the first time at the Earth’s poles. And the numbers were frightening. Over the Antarctic, 70% of the protective gas had disappeared, while 30% had been depleted over the Arctic. Rowland and Sherwood won the Nobel Prize in chemistry in 1995 for their work in atmospheric chemistry.

Ozone is present is two layers of the atmosphere. About 10% of ozone is present in the troposphere (lower layer of atmosphere), located at a distance of about 10-16 km from the surface of the earth. The major part of ozone comprising of the remaining 90% is present in the upper layer of atmosphere called stratosphere located at the distance of about 50 km from the surface of the earth. It is this layer that is called the ozone layer. The sun radiates large variety of radiation including ultraviolet radiation, which is very harmful to humans. The ozone layer absorbs ultraviolet radiation and prevents it from coming to the surface of the earth thus saving human beings from harmful rays. This ozone layer in the stratosphere is considered to be “good ozone.” The ozone layer occurring naturally in the lower layers of the atmosphere helps remove the pollutants from the surface of the earth.

On this day primary and secondary school teachers around the world organize classroom activities that focus on topics related to the ozone layer, climate change and ozone depletion. Other activities are organized by different community groups, individuals, schools and local organisations across the world and include: The promotion of ozone friendly products; special programs and events on saving the ozone layer; the distribution of the UNEP’s public awareness posters to be used for events centered on the International Day for the Preservation of the Ozone Layer; and the distribution of awards to those who worked hard to protect the earth’s ozone layer.

ozone |ˈōˌzōn| noun
A colourless unstable toxic gas with a pungent odour and powerful oxidising properties, formed from oxygen by electrical discharges or ultraviolet light. It differs from normal oxygen (O2) in having three atoms in its molecule (O3).
• Short for ozone layer .
informal Fresh invigorating air, esp. that blowing onto the shore from the sea.
DERIVATIVES
Ozonic |ōˈzänik| adjective
ORIGIN mid 19th century: From German Ozon, from Greek ozein ‘to smell.’

1 comment:

  1. Oh, I love the new look Nicholas!
    We don't hear as much about the Ozone layer hole nowadays as climate change has upstaged it. But I guess the hole is still there....
    Good post!

    ReplyDelete