International Day for the preservation of the ozone layer
"Ozone: All there is between you and UV"

Salam Gunakanta Singh *

Ozone Layer

The ozone layer or ozone shield refers to a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It contains high concentrations of ozone (O3) relative to other parts of the atmosphere, although still very small relative to other gases in the stratosphere.

The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometres (12 to 19 mi) above Earth, though the thickness varies seasonally and geographically. Ozone plays a very important role in our atmosphere. Although it is toxic to breathe directly, without it, life as we know it could not exist.

Ozone Depletion

Ozone depletion describes two distinct but related phenomena observed since the late1970s: a steady decline of about 4% in the total volume of ozone in Earth's stratosphere (the ozone layer), and a much larger spring time decrease in stratospheric ozone a round Earth's Polar Regions.

CFCs and related compounds in the atmosphere Chlorofluorocarbons (CFCs) and other halogenated ozone depleting substances (ODS) are mainly responsible for man-made chemical ozone depletion. The total amount of effective halogens (chlorine and bromine) in the stratosphere can be calculated and are known as the equivalent effective stratospheric chlorine (EESC).

Consequences of Ozone Layer Depletion

Increased UV radiation, Biological effects, Basal and squamous cell carcinomas, cortical cataracts, malignant melanoma, increased tropospheric ozone, increased production of vitamin D, Effects on non-human animals, Effects on crops. And lastly causes skin cancer to the human.

Montreal Protocol

The Montreal Protocol is an international agreement signed on 16 September 1987 to protect the ozone layer by limiting the production and use of ozone-depleting substances, mostly chlorofluorocarbons and halons. This protocol is widely hailed as the most successful environmental policy of our time. The latest Scientific Assessment of Ozone Depletion, a requirement of the Montreal Protocol, has stated that ozone is on the road to recovery.

Ozone in the tropics and mid-latitude, which has been depleted by 2.5% since1980, is expected to recover back to 1980 levels by the middle of this century. Antarctic ozone is also scheduled to recover, but not until the later part of this century.

Not only has The Montreal Protocol succeeded in protecting the ozone layer, thus preventing up to two million annual cases of skin cancer by 2030, as ozone depleting substances are also very potent greenhouse gases it has also had a large impact on slowing human induced climate change. For example, emissions of ozone depleting substances in 1987 were equivalent to emitting 10 giga tones of CO2 per year. This has since been reduced by 90 percent.

Significant Of The Day

In 1994, the UN General Assembly proclaimed 16 September the International Day for the Preservation of the Ozone Layer, commemorating the date of the signing, in 1987, of the Montreal Protocol on Substances that Deplete the Ozone Layer (resolution 49/114).States were invited to devote the Day to promote activities in accordance with the objectives of the Protocol and its amendments.

The ozone layer, a fragile shield of gas, protects the Earth from the harmful portion of the rays of the sun, thus helping preserve life on the planet. The phase-out of controlled uses of ozone depleting substances and the related reductions have not only helped protect the ozone layer for this and future generations, but have also contributed significantly to global efforts to address climate change; furthermore, it has protected human health and ecosystems by limiting the harmful ultraviolet radiation from reaching the earth.

Theme

This year marks the 30th anniversary of the Vienna Convention for the Protection of the Ozone Layer, an important milestone in the protection of the ozone layer. The theme for the celebration of the anniversary and this year's International Day for the Preservation of the Ozone Layer to be marked on 16 September is, "30 years of healing the ozone together." The theme is supported by the slogan, "Ozone: All there is between you and UV."