Day to protect the ozone layer of the earth

Ozone is a thin layer of atmosphere in the air that surrounds the earth. Ozone has precious properties that the ultraviolet (UV) radiation of the sun should be considered as a protective shield protecting people and life on the ground from the harmful effects of UV. In recent decades the ozone layer has been strongly reduced due to man-made chemicals. Since 1995, the United Nations takes September 16 every year as an international day to protect the ozone layer.

Ozone is a thin layer of atmosphere, accounting for a very small proportion of the air surrounding the earth. Scientists calculate that every 10 million molecules of air, on average, only three ozone molecules. Although not much, ozone molecules have a valuable property of absorbing the ultraviolet (UV) radiation of the sun, which is not found in any other gas in the atmosphere. With this characteristic, ozone really becomes an important shield to protect people and species on the ground from the harmful effects of ultraviolet rays.

Ozone is formed in the stratosphere due to the influence of solar radiation on oxygen molecules; is an unsustainable molecule made up of three oxygen atoms (O3). The ozone molecule is green, concentrated mainly in the stratosphere, the height from 16 to 4

The hole in the ozone layer has been taken since 1999
(Photo: NASA)

8 km from the ground, forming an ozone layer, with a thickness of 24 km. Scientists have discovered sustainable chlorine and bromine-containing chemical compounds in the chlorine-phosphor-carbon (CFCs) component, gases released from aerosols, refrigeration equipment such as refrigerators, air conditioners; Industrial detergent . is the main cause of ozone depletion. As the ozone layer declines, UV radiation to the earth increases. When ozone concentration decreased by 1%, UV radiation increased by 1.3%. The increase of UV radiation increases the likelihood of skin cancer, cataracts, destruction of the human immune system, reducing crop productivity and imbalance of marine ecosystems.

According to the World Meteorological Organization (WMO) and the UN Environment Program (UNEP), the ozone layer of the earth has plummeted in recent decades. The ozone layer was discovered for the first time in 1986, often appearing in August and reaching the highest level at the end of September every year in Antarctica, averaging up to 10 million square miles (one mile = 1.6 km). ); especially in 2003 reached 11.2 million square miles.

Recognizing the dangers of ozone depletion, the international community has called on all countries to limit the production and use of ozone-depleting substances (ODS). With the efforts of UNEP and WMO, After years of intense negotiations, in March 1985, the Vienna Convention on the protection of the ozone layer was signed by the first 21 countries. In 1987, the Montreal Protocol was signed, to date there are 189 member countries, in order to concretize solutions and commitments of the Vienna Convention parties, ensuring that the convention is implemented effectively.

The Montreal Protocol also provides trade restrictions for ODS substances, establishing multilateral funds (contributed by the industrialized countries to contribute) to assist developing countries in executing this letter

The Montreal Protocol was amended and supplemented twice in 1990 and 1992 to enhance the phase-out of ODS elimination schemes, on the principle of not harming consumers in reducing substances. ODS. Developing countries, extended for ten years more than developed countries in the elimination of ODS substances, require financial assistance and technology transfer without using ODS to implement these reductions. This substance follows the terms of the Montreal Protocol. On average, the Multilateral Fund spends about US $ 150 million annually to help companies in developing countries shift from producing CFC2-containing products to products using non-destructive substances (or destroying at a level less) ozone layer such as HCFC2, HFC2 and other chemicals in products such as hair spray, air conditioning, refrigerator . $ 2.1 billion has been spent over the years to protect the ozone layer of the earth.

Thanks to the efforts of the countries and the international community, after decades of destruction, the ozone layer of the earth is recovering. The UNEP and WMO report released at the end of August said the ozone layer's recovery was slower than expected by scientists. It is predicted that by 2049, ozone in major regions such as Europe, North America, Asia in the Northern Hemisphere and South Australia, Latin America, and Africa will be able to return to the status of before 1980, slowly. more than five years compared to the prediction made in 2002. In the Antarctic, where the ozone layer gap has continued to spread over the past 30 years, it is not until 2065 that the ozone layer recovers, 15 years later than expected. The rate of ozone layer recovery in these areas is slow mainly due to the inability to control the increased CFC gas volume under the Montreal Protocol.

This year, the International Day of Protection of the Ozone (September 16) is celebrated by members of the Vienna Convention and the Montreal Protocol, with the theme of Saving Life on Earth to raise awareness and coordinate action. protect the ozone layer of the earth.

THANH TRA