Presentation on theme: "Major Causes For Environmental Problems"— Presentation transcript:
1Major Causes For Environmental Problems Gas emissionsDeforestation and forest firesGreenhouse effectsRadioactive contamination
2Gas emissionsGas emissions are the gases that are released in the atmosphere by cars, airplanes, factories etc. Those gases are very harmful for the environment and the humans. They are responsible for the greenhouse effect and the acid rain . Some of them are greenhouse gas and carbon dioxide.
3Greenhouse gasA greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth’s atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects. Greenhouse gases greatly affect the temperature of the Earth; without them, Earth's surface would be on average about 33 °C (59 °F) colder than at present
4Carbon dioxideCarbon dioxide (chemical formula CO2) is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state, as a trace gas at a concentration of 0.039% by volume.
7DeforestationDeforestation is the removal of trees in a forest. The main causes are to build roads or for urban use. As a result, the production of oxygen is being reduced. Furthermore, many of the animals who used to live there lose their houses and most of them have nowhere else to go as a result to die.
10Forest firesThe four major natural causes of wildfire ignitions are lightning, volcanic eruption, sparks from rock falls, and spontaneous combustion. By the fires, tones of CO2 are produced and thousands of km2 of forest are destroyed.Spacefoto from the fires in Greece in the summer of 2007
11Greenhouse effectThe greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere. As a result, the temperature there is higher than it would be if direct heating by solar radiation were the only warming mechanism.Solar radiation at the high frequencies of visible light passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.The greenhouse effect was discovered by French mathematician Joseph Fourier in 1824, first reliably experimented on by Irish physicist John Tyndall in 1858, and first reported quantitatively by Swedish scientist Svante Arrhenius in 1896.
13Ozone depletionOzone depletion describes two distinct but related phenomena observed since the late 1970s: a steady decline of about 4% per decade in the total volume of ozone in Earth's stratosphere (the ozone layer), and a much larger springtime decrease in stratospheric ozone over Earth's polar regions. The latter phenomenon is referred to as the ozone hole. In addition to these well-known stratospheric phenomena, there are also springtime polar troposphere ozone depletion events.The details of polar ozone hole formation differ from that of mid-latitude thinning, but the most important process in both is catalytic destruction of ozone by atomic halogens. The main source of these halogen atoms in the stratosphere is photo dissociation of man-made halocarbon refrigerants (CFCs, freons, halons). These compounds are transported into the stratosphere after being emitted at the surface. Both types of ozone depletion were observed to increase as emissions of halo-carbons increased.
14CFCs and other contributory substances are referred to as ozone-depleting substances (ODS). Since the ozone layer prevents most harmful UVB wavelengths (280–315 nm) of ultraviolet light (UV light) from passing through the Earth's atmosphere, observed and projected decreases in ozone have generated worldwide concern leading to adoption of the Montreal Protocol that bans the production of CFCs, halons, and other ozone-depleting chemicals such as carbon tetrachloride and trichloroethane. It is suspected that a variety of biological consequences such as increases in skin cancer, cataracts, damage to plants, and reduction of plankton populations in the ocean's photic zone may result from the increased UV exposure due to ozone depletion.
15Radioactive contamination Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases (including the human body), where their presence is unintended or undesirable, or the process giving rise to their presence in such places. Also used less formally to refer to a quantity, namely the activity on a surface (or on a unit area of a surface).As with other contamination, radioactive contamination refers only to the presence of the unintended or undesired radioactivity, and gives no indication of the magnitude of hazard involvedRadioactive contamination is a result of the 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment.
16This is a totally blind long-nose sucker fishcaught downstream from the Beaverlodge uranium mill (early 1980s). This fish is a casualty of radioactive and heavy metal pollution — the eyes have no pupils. Blindness in fish is a known result of radioactive contamination from uranium mines; fish accumulate so much radioactivity in their bodies that in some areas immediately downstream from uranium mines, they present a health hazard if eaten regularly.
17Environmental groups in Greece Georgina Kakaletri G’1/gRudolph Maslias G’5/gPanos Pappas G’1/gKonstantinos Svourakis G’4/g
19ARCTUROSThe ARKTOYROS is a non-governmental, non-profit environmental organization founded in 1992 for the protection of wildlife and natural environment through field research, scientific study, public awareness, environmental education and volunteer to protect wildlife, enhance biodiversity and sustainability in Greece and abroad.ActivitiesBrown bears once ranged all across Europe, but human encroachment on their forest habitats have made them an endangered species. Through the efforts of Arcturos, the size of the Greek brown bear population appears to have doubled in recent years.The organization also undertakes the rescue of bears kept captive in inhumane conditions—such as the notorious "dancing bears", which are taken as cubs to be trained following the killing of their mother, as well as orphan bears and those improperly kept in zoos.
20HELMEPAThe Hellenic Marine Environment Protection Association (HELMEPA), established in 1982, is Europe’s first private sector voluntary marine environment protection association.HELMEPA's aims are to eliminate ship-generated marine pollution and enhance safety at sea. The Association trains seafarers and executives so that they are aware of safety and the protection of the marine environment," .HELMEPA supports governments in ratifying and implementing international conventions on the protection of the marine environment.
21Animal WelfareThere are animal activists who claim that Greeks don't care about animals and who send out pictures of suffering puppies because it makes them feel like they are helping them. They tell people to boycott Greece as if that will make the plight of animals any better. But the people in Greece who are actually helping animals are those on the front lines, in the streets and neighbourhoods of Athens and in the villages and countryside and they need your support.These organizations below are doing what they can do help animals and to educate people in an effort to eliminate animal cruelty. They need volunteers and money so if you care about the plight of animals in Greece contact one or more of them.
22Hellenic Ornithological Society GreenpeaceThe Greek branch of this worldwide organisation for environmental action can be contacted at its Athens offices on /5 or or through its websiteHellenic Ornithological SocietyThis organisation works with international birdlife organisations, aims to protect indigenous species and keep safe havens for migratory birds on their travels. Conducts research into, and provides data about, populations of wild birds. Call
23MedassetThis organisation sets up conservation projects and awareness campaigns about all species of sea turtle and lobbies the government to formulate and enforce legislation to protect indigenous species. Call or
25CONTENTS City problems (Katie Statiri) Recycling (Sylia Giakumaki) Forest fires (Tortzina Teza)Ozone layer (Eutihia Albanou)Our life without environmental problems (Eleana Koutsoubeli)
26City Problems-Solutions Gas reductionIt may take up to one year for one tree to fix the amount of CO2 found in 3 litres of gas, so:1.Windmill kits are inexpensive and a great source of electricity in windy areas. Solar energy, especially solar collectors for water heaters, is possible for most homes. Some companies will buy back excess electricity.2.Reduce the usage of refrigerants and air-conditioners5. Use public transportation or carpool for long trips.6.Concider ditcing the car altogether7. Research biodiesel8.Research energy efficient, electric, hybrid and diesel engines when buying a new car, motorbike or scooter3.Charge batteries rather then throw them away4. Walk short distances rather than drivesubstances
28Waste Reduction Habits 12 good habits for reducing waste! Opt for reusable bagsPut a « No Junk Mail » sticker on your letterboxAvoid food wasteBuy in bulk or in large-size packagingBuy eco-rechargeable or refillable productsDrink tap waterLimit use ofthe printerRestrict printer usageStart compostingDonate old clothingBorrow or hire toolsRepair goods and appliances
38HOW TO SAVE THE ENVIRONMENT Biomassfluorescent lampsPhotovoltaicWater heaters
39BiomassBiomass, as a renewable energy source is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel.
40In the first sense, biomass is plant matter used to generate electricity with steam turbines & gasifiers or produce heat, usually by direct combustion. . Examples include forest residues (such as dead trees, branches and tree stumps, yard clippings, wood chips and even municipal solid waste. In the second sense, biomass includes plant or animal matter that can be converted into fibers or other industrial chemicals such as biofuels. Industrial biomass can be grown from numerous types of plants, including miscanthus , switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane, and a variety of tree species, ranging from eucalyptus to oil palm.
41Thermical conversion … These are processes in which heat is the dominant mechanism to convert the biomass into another chemical form. The basic alternatives of combustion, torrefaction, pyrolysis, and gasification are separated principally by the extent to which the chemicalinvolved are allowed to proceed (mainly controlled by the availability of oxygen and conversion temperature). reactions ivlolved are allowed to be proceed (mainly controlled by the availability of oxygen and conversion temperature).
42Biochemical conversion A range of chemical processes may be used to convert biomass into other forms, such as to produce a fuel that is more conveniently used, transported or stored, or to exploit some property of the process itself.Biochemical conversionAs biomass is a natural material, many highly efficient biochemical processes have developed in nature to break down the molecules of which biomass is composed, and many of these biochemical conversion processes can be harnessed.
44The incandescent lampThe incandescent lamp comprises a thin metal thread, heavy, usually tungsten , wrapped in spirals. This is claimed by its edges welded to two thicker wires in which the voltage which sets the electric charges in motion which forces the thread to illuminate the heating. When the length of the filament is larger than 2 cm it is supported and intermediate non-electrified wires in a radial arrangement. This structure is enclosed in a glass ampoule spherical or elliptical low-pressure gas.
45Causes of damage…Main causes of damage and "death" of the incandescent lamp is the sublimation of the tungsten filament thickness progressively decreases until it cut to the point where it is weakest. The sublimation is also the reason to prevent the increase of temperature. Other major causes of reduced life are:1. Increases in voltage, an increase of approximately 5% reduction in life observed 30%.2. Switching on the lamps thereof, that means that in 1 / 10 sec is power almost 12 times more than normal. This is because the resistance presented by the tungsten filament is approximately 12 times lower when it is cold compared to the resistance shows that when it is hot, that is in operation
46The fluorescent lampThe use of such common bulbs today, although a low efficiency, is very broad due to the very low cost. The fluorescent lamp is a gas discharge lamp that uses electricity to stimulate pressure mercury . The lamps are available in various shapes and sizes, with the most common of these tube (used for lighting offices and shops) and compact fluorescent lamp (used for lighting homes). Manufactured in standard lengths, the straight, and diameters, circular and grid voltages 220 V and 110 V.
47Photovoltaic…Photovoltaic (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material. Materials presently used for photovoltaic include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium gallium selenide/sulfide.
48Continuing…The photovoltaic effect is the creation of a voltage (or a corresponding electric current) in a material upon exposure to light. Though the photovoltaic effect is directly related to the photoelectric effect, the two processes are different and should be distinguished.[The photovoltaic effect was first observed by Alexandre-Edmond Becquerel in 1839.