Ozone layer depletion ppt
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The document discusses the ozone layer and the factors contributing to its depletion. It notes that the ozone layer shields the Earth from UV radiation and was discovered to be depleting in the 1970s due to ozone-depleting substances (ODS) released into the atmosphere. The main ODS that damage the ozone layer are listed. The text then outlines the principal steps in how ODS reach the stratosphere and cause ozone depletion, as well as the human health and environmental effects of increased UV exposure due to ozone layer thinning. International agreements like the Montreal Protocol and domestic policies in countries like the Philippines are mentioned as mitigation efforts to prevent further ozone depletion.
Ozone layer depletion ppt
- 4. • Troposphere • Stratosphere
- 6. • 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
- 7. • 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.
- 9. • seasons • weather conditions, and • solar cycles
- 12. Ozone layer is being destroyed by a group of manufactured chemicals that are called ODS or Ozone-Depleting Substances.
- 13. 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)
- 14. The Principal Steps in Stratospheric Ozone Depletion Caused by Humans Emissions Accumulation Transportation Chemical Removal Conversion Reaction
- 15. The Process of ODS Reaching the Atmosphere
- 17. 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
- 18. • Reduced effectiveness of immune system • Respiratory illness and heart problems
- 19. Effects on the Environment • Global warming • Climate change • Crop and forest damage • Infections and skin diseases on animals • Less ocean plankton • Less fish harvest
- 20. Marine Terrestrial Humans Ecosystems Ecosystems Air Quality Materials
- 21. Mitigations
- 22. 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
- 23. 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
- 24. • Republic Act 9003 or the Ecological Solid Waste Management Act. • Presidential Decree 1144
- 25. 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.
- 27. Be informed Be Understand reminded Sustainable development Follow Know our responsibilities Educate ourselves
Editor's Notes
- #5: Troposphere - It is found at the Earth’s surface. - Ozone in this area is “bad” because it dirties the air and helps make smog, which is unhealthful to breathe.- It is a layer miles above the Earth’s surface. - Ozone in this area is “good” because it absorbs some of the sun’s ultraviolet rays. - It is the region where the ozone layer is located.
- #10: but these are all part of a natural cycle where ozone is continually formed, destroyed and formed again.
- #13: ODS are very stable, nontoxic and environmentally safe in the lower atmosphere, which is why they became so popular in the first place. However, their very stability allows them to float up, intact, to the stratosphere. Once there, they are broken apart by the intense ultraviolet light, releasing chlorine and bromine.
- #21: The impact on marine ecosystems, especially on phytoplankton and larvae of higher organisms , are of particular concern. Damage in the food chain, 30 percent of the world’s animal protein comes from the sea Damage in the oceanic carbon cycle by which atmospheric carbon dioxide is converted into oxygen. Reduced terrestrial plant productivityReduced food security and food quality Changes in microbial biodiversity with consequences for soil fertility and plant disease. Numerical models predict that future changes in UV radiation and climate will modify the trends and geographic distribution of hydroxyl radicals, thus affecting urban and regional photochemical smog formation, as well as the abundance of several greenhouse gases. The impacts of air pollution on human health and the environment will be directly influenced by future changes in climate, emissions of pollutants, and stratospheric ozone. Today's materials are somewhat protected from UVB by special additives. Therefore, any increase in solar UVB levels will therefore accelerate their breakdown, limiting the length of time for which they are useful outdoors.
- #23: Phils. Signed the protocol- Jan 1, 1989-agreed on 16 September 1987 and entered into force on 1 January 1989
- #24: Republic Act 6969 or the Toxic Substances and Hazardous and Nuclear Wastes Control Act. This Act mandates the regulation, restriction, or prohibition of the importation, manufacture, processing, sale, distribution, use and disposal of chemical substances and mixtures that present unreasonable risk and/or injury to health and the environment. paved way for the control and regulation of dioxins and furans releases to the air.
- #25: provides the requirements that contributes to the reduction of the emission of dioxins and furanscreated Fertilizer and Pesticides Authority an agency that mandates to regulate and monitor production, importation and use of pesticides and other agricultural chemicals in the country.