The impact of ozone depletion

The bear upon of ozone depletionThe ozone is a thin mould of triatomic oxygen molecules intendd within the air travel which is capable of gripping lethal ultraviolet (UV) beam of light from the fair weather. Ozone occurs naturally within the stratosphere, and it accounts for about 90% of the total ozone molecules in the atmosphere, comp ared to the tropospheric ozone which forms a major air pollutant and accounts for only10%. Ozone class in the atmosphere extends goodly up to about 50Km, and there are approximately 12,000 ozone molecules per 1 billion molecules of air, musical composition less quantity exist in the troposphere of about 20-100 molecules per billion molecules of air.Stratospheric ozone is make through and through a continuous complex process of photo chemic reception involving the splitting of oxygen molecules into two oxygen atoms by solar cogency and each atom gain ground combines with oxygen molecules to produce ozone. Be typeface the process is sun lightniness dependent, more ozone is produced at lower latitudes imputable the concentration of risque solar beam of light round the equator as such ozone is continually produced and layed in these complex chemical replys. The world-wide distribution of ozone depends on conditions such as the availability of bromine and atomic number 17 in the atmosphere, high solar impregnation and latitudinal location that favour the mathematical product of the molecules.Without this layer, UV-B irradiation when reaching the ground is capable of damaging plant and animal tissues, increasing the risk of health problems such as skin cancer in humans as well as destroying both terrestrial and aquatic ecosystems.Depletion of the ozone has been observed oer the years due to the wall socket of chemical substances into the atmosphere by humans. In 2005, scientists do observed the increase in ozone depleting substances (ODS) which results to the thinning of this protective layer over Arctic and Antarctic poles by about 30 50%, and a spherical average reducing of about 3 6% compared to the pre 1980 levels. The process of depletion begins with the discommode of the ozone depleting substances (ODS) such as chlorine and bromine and chlorofluoro snows (CFCs) broadly speaking from human sources. These gases further accumulate into the atmosphere for some time depending of their occupant times and then expressed to the stratosphere through vertical mixing. These non-reactive gases are further reborn into reactive compounds by UV radiation, then chemical reactions takes place to destroy the ozone layer. Finally, these gases are transported back to the troposphere where they are removed through precipitation.Climate diverge and ozone layer depletion are interlinked beca rehearse ozone itself is a greenhouse gas and together with early(a) ozone depleting substances such as bromine (Br) and chlorine (Cl) contribute to global heating plant. whence any shifts in the atmospheric concentration and distribution of ozone will have significant impact on the global humour system.Release of these (ODS) substances including atomic number 6 dioxide and chlorofluoro carbons has a cooling achievement on the stratosphere. This cooling yield favours the chemical reactions in chlorine and bromine thereby contributing to the formation of cold Stratospheric Clouds (PSC), a condition that results in the depletion of ozone.Studies have proved that the decrease in stratospheric ozone observed over Antarctica led to substitutes in the moveions between the stratosphere and the earthly concern. These changes alter the atmospheric circulation particularly the North Atlantic oscillation (NAO), which in while has an burden on variation of climate around the Atlantic.Depletion of the ozone has an another(prenominal) significant effect on the global biogeochemical one shots which has pro fix effect on the climate system. augment in the amount UV-B modifies the carbon vibration by affecting the ingestion of CO2 by plants during photosynthesis, as well as carbon terminal in plants tissues as biomass.Because the terrestrial ecosystem serves as a net reach for carbon, changes in the amount of UV radiation is capable of disturbing the photosynthetic and respiration processes which link the atmospheric carbon and terrestrial carbon expenditure and release. Within the terrestrial ecosystems, certain plant species become more persuasible to increased UV radiation, hence reducing their ability to capture and storage atmospheric carbon dioxide.Furthermore, a change in the UV radiation increases the aim of productivity of soil micro organisms such as fungus kingdom thereby increasing the station of carbon release from biomass decomposition. This accelerated turn over time of carbon through this process of photo adulteration or photo transformation decreases the storage capacity of the soil as a major carbon sink, as such contributing t o global melting. Scientific projections from models suggest a major shift in global ecosystems from cooler and wetter to warmer and drier conditions in response to climate change-UV interaction.Another important linkage between ozone depletion and climate change is the transformation of the marine biological pump of atmospheric carbon dioxide into the ocean hind end under the influence of UV radiation. Coloured dissolved native social function (CDOM) present in aquatic primary producers which is useful in absorbing UV in the ocean undergoes photo bleaching under higher dose. thereby resulting in the loss of the pigment and consequently allow more UV acuteness into the ocean and edit the ability of aquatic plants to fix carbon during photosynthesis.Also, thermal stratification of ocean pisss occur as a result of increased CO2 from human- induced emissions decreases mid-water oxygen around the enlightenment of 200-800m, which affect carbon uptake by the oceans. This stratifi cation affect vertical mixing of substances such as bromocarbons found in tropical waters. under(a) the influence of UV, certain ozone depleting reactive radicals such as bromine oxide (BrO) are produced.Conversely, climate change also has a significant influence on ozone layer depletion. This influence whitethorn either accelerate or slow the ozone process of retrieval. Climate change induces the formation of Polar stratospheric clouds around the high latitudes which when exported to mid-latitudes generate further depletion of the ozone around such areas. Studies have shown that radiative forcing from global warming may help the ozone to recover because it tends to reduce the formation of such clouds that interact with gases in the atmosphere to destroy the ozone. Evidence was observed in the simplification in the loss of ozone over Antarctica between 2001 and 2004 during the spring period. Since ozone depletion is the principal cause of reduction in temperature of the stratosph eric ozone by about (-0.17C/ decade), increase in the emission of Green House Gases (GHG) into the atmosphere will have a warming effect thereby reversing this loss. Reactions involving compounds of halogen are directly affected by UV-B and climate change. Halomethane emissions attributed to climate change react with UV-B and consequently regulate ozone availability in the atmosphere. Climate change induced increase in temperature stimulates the release of methyl bromide and methyl iodide from certain species of plants under the influence of UV radiation. Also, climate change result in the alteration of the global hydrological cycle by increasing the rate of precipitation and eutrophication of organic carbon into rivers and streams from land. Mineralisation of this organic material takes place under the influence of UV to further release carbon into the atmosphere and contribute to global warming.In addition, global warming caused by human-induced increase in Nitrogen oxide (NO), C arbon monoxide (CO), and Methane (CH4) from bush fires increases the rate of production of ozone in the troposphere. As such global warming may increase the amount of aerosols present in the atmosphere which subsequently affects the rate of ozone photolysis by about 6-11%.Other natural factors contributing to climate change such as volcanic eruption and variation in sun-spot action at law affect ozone layer depletion. Because ozone depletion in the stratosphere is formed under the influence of solar energy, any increase in the amount of radiation coming from the sun will increase the amount of ozone in the atmosphere. Variation in the 11-year sun spot activity indicate an observed increase and decrease in ozone concentration with corresponding maximum and minimum solar cycles respectively. Furthermore, The Brewer-Dobson circulation is responsible for the transport of sulphur gases from volcanic eruptions into the stratosphere. The ascending branch of this circulation transport gas from the tropical zone upwards while the descending branch return the gases back to the troposphere in the high latitudes.Volcanic eruptions also release sulphate gases into the atmosphere. These gases significantly reduce the rate of multiplication of incident radiation from the sun and decrease the production of ozone. Other natural factors such as the release of methyl bromide into the atmosphere from rice cultivation deplete the ozone and thus increase the penetration of UV radiation.There is a strong relationship between UV radiation, carbon and nitrogen cycling which has a significant climate change implications. Increase in UV can affect the nitrogen cycle through changes in the rate of organic matter decomposition of nitrogen containing compounds through nitrogen fixation. Nitrogen compounds such as ammonia and process are continuously cycled within the biosphere in series of complex processes. dissolve organic Nitrogen (DON) reacts with UV radiation to break it down int o more soluble ammonium compound through the process of photoammonification. All these processes determine rates of carbon uptake and decomposition in the global carbon cycle. Report from the World Meteorological Organisation (WMO 2003) indicate feedback mechanisms from increasing water vapour into the atmosphere, which increases the availability of odd-hydrogen radical that leads to ozone depletion by disturbing nitrogen and chlorine cycles.Within the marine ecosystem, hydrolysis of bromine and iodine takes place by photolysis reaction in the ocean to produce ozone depleting substances. Marine phytoplanktons like algae found in tropical waters emit halogen compounds into the troposphere. Also, the interaction between UV-B radiation and the sulphur cycle contribute to climate change. Pollutants such as dimethyl sulfide (DMS) and carbonyl sulphide (COS) are emitted as aerosols that have cooling effect on the atmosphere.Climate change can also affect the propagation of planetary wave s into the atmosphere (Rhind et al.,2005a2005b Scott and Polvani, 2004 Scott et al., 2004). Climate models suggest a significant impact of climate change on troposphere-stratosphere interaction. Studies by Rhind et al. (2001) estimated in about 30% in this interaction resulted from doubling of carbon dioxide amount in the atmosphere. theme by Scaife (2001) shows a decadal increase of about 3% as a consequence of climate change. All these interactions have profound effect on the transport of ozone depleting substances into the stratosphere as well as their removal from the stratosphere back to the earth surface.In order to minimize or eliminate the impacts of ozone layer depletion, the Montreal protocol on Substances that Deplete the Ozone Layer was signed in 1987, and then came into ramp in 1989. Under this agreement, various nations that signed up the treaty pledge to reduce the production and consumption of harmful halogen gases .This reduction target begins with the decelera tion down the production and then their eventual phase out through the use of substitute gases. The use of ozone friendly Hydrochloroflourocarbons (HCFCs) was adopted to substitute the use of CFC-12 in the manufacture of refrigerants and foam making agents.The Montreal Protocol has successfully achieved a reduction in the concentration of chlorine in the global atmosphere in the late 20th century. Another important achievement is the reduction in the production of methyl chloroform and CFCs to a near nothing level at the global scale. Towards the end of this century, substances such as methyl chloride and methyl bromide are expected to be eliminated from the atmosphere due to the projected stabilisation and subsequent reduction in their production.Complete recovery of the ozone to pre 1980 level is expected under strict compliance to the Montreal Protocol by the middle of this century, with slower recovery rate predicted by computer models around the Antarctic ozone hole.In conclus ion, human induced climate change and ozone layer depletion are closely inter-related. With ozone depletion exacerbating the rate of global warming while climate change continues to deplete the ozone. Therefore necessary measures must be taken under the Montreal and Kyoto Protocol provisions to reduce the emission of ODS and other green house gases in order to save the planet from consequences of further warming effects on human health and the environment.