OZONE LAYER DEPLETION

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Troposphere Stratosphere

• Ozone layer is a thin, fragile shield that contains relatively high concentrations of ozone.

• It shields the entire Earth from much of the harmful UV radiation that comes from the sun

• Damage in the ozone layer will naturally mean the entry of harmful rays in to the atmosphere. • In the 1970s, the scientists discovered that the ozone layer is being depleted.

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seasons

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weather conditions, and

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solar cycles

Ozone layer is being destroyed by a group of manufactured chemicals that are called ODS or OzoneDepleting Substances.

The main ODS are the following: • Chlorofluorocarbons (CFC 11, CFC 12, CFC 13) • Methyl bromide (CH3Br) • Halons (halon-1211, halon-1301, halon-2402) • Carbon tetrachloride (CCI4) • Hydrochloroluorocarbons (HCFC 22 and HCFC 123)

The Principal Steps in Stratospheric Ozone Depletion Caused by Humans

Emissions

Accumulation

Transportation

Removal

Chemical Reaction

Conversion

The Process of ODS Reaching the Atmosphere

The effect of ozone depletion is the increased UV-B radiation reaching Earth’s surface. Effects on Humans • Sunburn •Sun-damaged skin •Cataracts •Snow blindness •Skin cancer

• Reduced effectiveness immune system • Respiratory heart problems

illness

of and

Effects on the Environment

• Global warming • Climate change • Crop and forest damage • Infections and skin diseases animals • Less ocean plankton • Less fish harvest

on

Marine Ecosystems

Humans

Air Quality

Terrestrial Ecosystems

Materials

Mitigations

When an ozone hole was discovered, several countries unite to prevent the continuous depletion of the ozone layer by implementing policies and other preventive measures. • The Montreal Protocol on Substances that Deplete the Ozone Layer

Philippines’ Laws and Policies • Republic Act 6969 or the Toxic Substances and Hazardous and Nuclear Wastes Control Act. • Republic Act 8749 or the Philippine Clean Air Act of 1999

• Republic Act 9003 or the Ecological Solid Waste Management Act. • Presidential Decree 1144

Davao City has also implemented mitigating measures. The Local Government implemented the Davao City Ecological Solid Waste Management Ordinance 2009 (Section 7, Article 5 of the Ordinance 0361 series of 2010) - that provides the use of recyclable, biodegradable or reusable containers as food and beverage parcels started 28 June 2012.

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