Presentation on theme: "The atmosphere The atmosphere protects the earth from the sun's harmful rays. Shooting stars from space, which can be seen on a clear night, burn up when."— Presentation transcript:
The atmosphere The atmosphere protects the earth from the sun's harmful rays. Shooting stars from space, which can be seen on a clear night, burn up when they enter the atmosphere. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). Clic for more informations Troposhere Stratosphere Ionosphere
The stratosphere The stratosphere is a layer of Earth's atmosphere. The stratosphere is the second layer, as one moves upward from Earth's surface, of the atmosphere. The stratosphere is above the troposphere and below the mesosphere. OzoneOzone, an unusual type of oxygen molecule that is relatively abundant in the stratosphere, heats this layer as it absorbs energy from incoming ultraviolet radiation from the Sun.
The ionosphere The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth. In ionosphere we find the Ozone layerOzone layer
Air is made up mostly of Nitrogen and Oxygen. When we breathe we use Oxygen and give off Carbon Dioxide. The plants and trees absorb the Carbon Dioxide and give off Oxygen.Carbon Dioxide What is air? This layer is the nearest to the earth surface,that's why most effects on our life depends on it. Among them the most harmful ones are the acid rains and the greenhouse effect.acid rains greenhouse effect
Ozono is a gas found 10 to 15 kilometers above the Earth. It protects us from the sun's harmful ultra violet rays. The ozone layer can be damaged by pollution, especially CFC's found in Aerosols Look out for 'environmentally friendly 'and ' ozone friendly' Products.
Chluorofluorocarbons (CFCs), such as frigerants and propellants in Aerosolcans, release chlorine when they break down. Rising to the upper Atmosphere, the chlorine reacts with ozone (O 3 ) gas, reducing it to O 2 gas. The ozone layer in the upper atmosphere protect life on earth from the harmful ultraviolet rays in sunlight. Multinational agreement was reached in 1987 to phase out the use of these chemicals. However quantities of these chemicals already in the air would continue to deplete the ozone layer for decades.
Carbon dioxide and other gases added to atmosphere may cause global warming Carbon dioxide and other gases added to atmosphere may cause global warming The addiction of CO2 to the atmosphere by cellular respiration roughly balances the removal of carbon dioxide by photosynthesis.carbon dioxide CO 2 CO 2
All fossil fuels and many other fuels contain carbon. As these fuels are used they are releasing more and more carbon dioxide into the atmosphere.
sun Carbon dioxide takenin by plants for photosynthesis Carbon dioxide takenin by plants for photosynthesis plants Animals and humans Animals and humans respiration Fossil flues Human energy use Carbon dioxide Released into atmosphere Carbon dioxide Released into atmosphere dead material
Carbon dioxide and other gases added to the atmosphere may cause global warming. The rise of the agriculture and the Industrial Revolution triggered some profound environmental changes. A change that could alter the entire biosphere is rapid global warming. The addition of CO2 to the atmosphere by cellular respiration roughly balances the removal of CO2 by photosynthesis. What is troubling is the current rate of increase in atmospheric CO 2. Carbon Dioxide Other Gases
Carbon Dioxide is one of several so-called greenhouse gases (molecules that can trap heat and cause atmospheric warming, known as greenhouse effect). CO 2 absorbs infrared radiation and slows its escape from Earth.
Other greenhouse gases are methane and nitrous oxide, both of which are also increasing in the atmosphere as a result of fossil- fuel consumption, industry and agriculture. Fossils fuels power most of our industries, agricultural equipements and automobiles and they heat most of our homes. One of the major side effects of the combustion of fossil fuels is an increase in atmospheric CO2
We must stop chopping down the rain forests as many rare species will become extinct and life giving oxygen which is produced by the trees will be reduced.
In addition to flooding, a warming trend might alter patterns of global precipitation. For instance, the grain belts of the central United States and centra Asia might become much direr and unable to support the crops currently grown there. Furthermore, forested areas in seminarid zones could lose their trees and become deserts.
Studies of climatic changes through geological time mathematical models lead some climatologists to predict that in the next 50-100 years, at the present rate greenhouse gases are increasing, atmospheric temperatures could rise by about 2-5°C. It is also possible that as the temperature of the atmosphere increases, populations of soil bacteria will increase and in turn produce even more CO 2 and methane.
Acid rain is produced when poisonous gases from power stations and cars react together and dissolve in rainwater. The resulting rain and snow is often as strong as lemon juice. This rain kills trees, dissolves stones on historic buildings, enters rivers and streams and kills the fish.
Emissions of the gases and nitrogen oxides contribute to the international problem of acid rain pollution. Sulphur dioxide emissions arise during combustion of fossil fuels. Including coal, oil and natural gas. Oxidation of sulphur dioxide forms Sulphur dioxide (SO 2 ), a colourless gas. It is soluble in water and it is transformed into sulphuric acid (H 2 SO 4 ), which falls as acid precipitation or 'acid rain'.Large quantities of sulphur Dioxide are released naturally when volcanoes erupt. The problem of acid rain is not a recent development,but we are much more aware of the damage caused by acid rain nowadays.
The Acropolis was built over 2000 years ago. The damage done is largely due to the pollution caused by cars and other vehicles in Athens -the most polluted city in Europe. Car engines burn petrol as a fuel and release acidic gases such as sulphur dioxide into the atmosphere. May other countries have also noticed an acceleration of damage to their cultural heritage.
How can pollution problems cause acid rain How can pollution problems cause acid rain ?
80 About 80% of the air is nitrogen.The high temperatures cause some of this nitrogen oxides to produce nitrogen oxides.These are some of the ways levels of nitrogen oxides can be reduced: In power stations Eliminate excess air by using the minimum amount of air needed for combustion Lower the combustion temperature In cars: Change the air Recirculate exhaust fumes Use catalytic converters
These are some ways we can reduce levels of sulphur dioxide in the air : Burn less fossil fuel Fuel desulphurisation Sulphur reduction during combustion by the addition of lime to coal duriing combustion Fuel gas remova l
How to treat damaged areas Fertilise damaged conifer forests with calcium,magnesium,potassium,zinc and manganese. Spread lime on affected lakes and forest.
Acid rain causes a variety of effects that harm or kill individual fish and reduce fish population numbers. In some cases,acid rain completely eliminates some fish species from certain bodies of wother and resultes in decrased biodiversity. As racid rain flows through soils, aluminum is released from the soli into the lakes and streams, resulting in a lower ph and a higher alluminium level. Low ph and increased aluminium levels are directly toxic to fish and cause them chronic stress. How does acid rain affect fish and other aquatic organisms? SPECIESOF ANIMALSAND PLANTS
Some types of plants and animals ar able to tolerate acidic waters. Others, however, are acid-sensitive and will die as the ph falls. Generally, the young of most species are more sensitive to envionmental conditions than adults.
BIOLOGICAL INDICATORS: SIGNS OF PULLUTION Biological indicators are useful for assessing levels of pollution 1. Lichens are sensitive to sulphure dioxide. By observing the type of lichens growing locally, environmental scientists can monitor the level of sulphur dioxide pollution. 2. Mosses are sensitive to air pollution and have disappeared from many metropolitan and industrial areas