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Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
Global Warming
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Global Warming

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global warming, its causes and effects on various flora and fauna

global warming, its causes and effects on various flora and fauna

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  • 1. GL OB A L W A RM IN G 1
  • 2. GLOBAL WARMING Global warming is the observed and projected increases in the average temperature of Earth's atmosphere and oceans. The Earth's average temperature rose about 0.6° Celsius (1.1° Fahrenheit) in the 20th century, see temperature graphs below. Global warming is the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation. The global average air temperature near the Earth's surface rose 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005. The Intergovernmental Panel on Climate Change (IPCC) concludes "most of the observed increase in globally averaged 2
  • 3. temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations" via the greenhouse effect. Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward. These basic conclusions have been endorsed by at least 30 scientific societies and academies of science, including all of the national academies of science of the major industrialized countries. While individual scientists have voiced disagreement with some findings of the IPCC, the overwhelming majority of scientists working on climate change agree with the IPCC's main conclusions. Climate model projections summarized by the IPCC indicate that average global surface temperature will likely rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the 21st century. The range of values results from the use of differing scenarios of future greenhouse gas emissions as well as models with differing climate sensitivity. Although most studies focus on the period up to 2100, warming and sea level rise are expected to continue for more than a thousand years even if greenhouse gas levels are stabilized. The delay in reaching equilibrium is a result of the large heat capacity of the oceans. Increasing global temperature will cause sea level to rise, and is expected to increase the intensity of extreme weather events and to change the amount and pattern of precipitation. Other effects of global warming include changes in agricultural yields, trade routes, glacier retreat, species extinctions and increases in the ranges of disease vectors. Remaining scientific uncertainties include the amount of warming expected in the future, and how warming and related changes will vary from region to region around the globe. Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gas emissions, but there is ongoing political and public debate worldwide regarding what, if any, action should be taken to reduce or reverse future warming or to adapt to its expected consequences. 3
  • 4. Causes of Global Warming “As human-caused biodiversity loss and climate disruption gain ground, we need to keep our sights clear and understand that the measure of a threat is not a matter of whether it is made on purpose, but of how much loss it may cause. It's an ancient habit to go after those we perceive to be evil because they intended to do harm. It's harder, but more effective, to "go after," meaning to more effectively educate and socialize, those vastly larger numbers of our fellow humans who are not evil, but whose behavior may in fact be far more destructive in the long run." (Ed Ayres, editor of Worldwatch magazine, Nov/Dec 2001) Carbon Dioxide from Power Plants : In 2002 about 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity generation. Coal accounts for 93 percent of the emissions from the electric utility industry. Coal emits around 1.7 times as much carbon per unit of energy when burned as does natural gas and 1.25 times as much as oil. Natural gas gives off 50% of the carbon dioxide, the principal greenhouse gas, released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Coal contains about 80 percent more carbon per unit of energy than gas does, and oil contains about 40 percent more. For the typical U.S. household, a metric ton of carbon equals about 10,000 miles of driving at 25 miles per gallon of gasoline or about one year of home heating using a natural gas-fired furnace or about four months of electricity from coal-fired generation. Carbon Dioxide Emitted from Cars : About 33% of U.S carbon dioxide emissions comes from the burning of gasoline in internal- combustion engines of cars and light trucks (minivans, sport utility vehicles, pick-up trucks, and jeeps).US Emissions Inventory 2006 page 8 Vehicles with poor gas mileage contribute the most to global warming. For example, according to the E.P.A's 2000 Fuel Economy Guide, a new Dodge Durango sports utility vehicle (with a 5.9 liter engine) that gets 12 miles per gallon in the city will emit an estimated 800 pounds of carbon dioxide over a distance of 500 city miles. In other words for each gallon of gas a vehicle consumes, 19.6 pounds of carbon dioxide are emitted into the air. A new Honda Insight that gets 61 miles to the gallon will only emit about 161 pounds of carbon dioxide 4
  • 5. over the same distance of 500 city miles. Sports utility vehicles were built for rough terrain, off road driving in mountains and deserts. When they are used for city driving, they are so much overkill to the environment. If one has to have a large vehicle for their family, station wagons are an intelligent choice for city driving, especially since their price is about half that of a sports utility. Inasmuch as SUV's have a narrow wheel base in respect to their higher silhouette, they are four times as likely as cars to rollover in an accident. The United States is the largest consumer of oil, using 20.4 million barrels per day. In his debate with former Defense Secretary Dick Cheney, during the 2000 Presidential campaign, Senator Joseph Lieberman said, "If we can get 3 miles more per gallon from our cars, we'll save 1 million barrels of oil a day, which is exactly what the (Arctic National Wildlife) Refuge at its best in Alaska would produce." If car manufacturers were to increase their fleets' average gas mileage about 3 miles per gallon, this country could save a million barrels of oil every day, while US drivers would save $25 billion in fuel costs annually. Carbon Dioxide from Airplanes : The UN's Intergovernmental Panel on Climate Change estimates that aviation causes 3.5% of global warming, and that the figure could rise to 15% by 2050. Carbon Dioxide from Buildings : Buildings structure account for about 12% of carbon dioxide emissions. Methane : While carbon dioxide is the principal greenhouse gas, methane is second most important. Methane is more than 20 times as effective as CO2 at trapping heat in the atmosphere. US Emissions Inventory 2004 Levels of atmospheric methane have risen 145% in the last 100 years. Methane is derived from sources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel production. Most of the world’s rice, and all of the rice in the United States, is grown on flooded fields. When fields are flooded, anaerobic conditions develop and the organic matter in the soil decomposes, releasing CH4 to the atmosphere, primarily through the rice plants. 5
  • 6. Water vapor in the Atmosphere Increasing : Water vapor is the most prevalent and most powerful greenhouse gas on the planet, but its increasing presence is the result of warming caused by carbon dioxide, methane and other greenhouse gases. Water vapor holds onto two-thirds of the heat trapped by all the greenhouse gases. As the Earth heats up relative humidity is able to increase, allowing the planet's atmosphere to hold more water vapor, causing even more warming, thus a positive feedback scenario. Because the air is warmer, the relative humidity can be higher (in essence, the air is able to 'hold' more water when its warmer), leading to more water vapor in the atmosphere, says the NCDC. There is much scientific uncertainty as to the degree this feedback loop causes increased warming, inasmuch as the water vapor also causes increased cloud formation, which in turn reflects heat back out into space. Nitrous oxide : Another greenhouse gas is Nitrous oxide (N2O), a colorless, non-flammable gas with a sweetish odour, commonly known as "laughing gas", and sometimes used as an anesthetic. Nitrous oxide is naturally produced by oceans and rainforests. Man-made sources of nitrous oxide include nylon and nitric acid production, the use of fertilizers in agriculture, cars with catalytic converters and the burning of organic matter. Nitrous oxide is broken down in the atmosphere by chemical reactions that involve sunlight. Deforestation : After carbon emissions caused by humans, deforestation is the second principle cause of atmospheric carbon dioxide. Deforestation is responsible for 20-25% of all carbon emissions entering the atmosphere, by the burning and cutting of about 34 million acres of trees each year. We are losing millions of acres of rainforests each year, the equivalent in area to the size of Italy. The destroying of tropical forests alone is throwing hundreds of millions of tons of carbon dioxide into the atmosphere each year. We are also losing temperate forests. The temperate forests of the world account for an absorption rate of 2 billion tons of carbon annually. In the temperate forests of Siberia alone, the earth is losing 10 million acres per year. City Gridlock : In 1996 according to an annual study by traffic engineers, it was found that drivers in Los Angeles and New York City alone wasted 600 million gallons of gas annually while just 6
  • 7. sitting in traffic. The 600 million gallons of gas translates to about 7.5 million tons of carbon dioxide in just those two cities. Carbon in Atmosphere and Ocean : The atmosphere contains about 750 billion tons of carbon, while 1020 billion tons are dissolved in the surface layers of the world's ocean. Also: Forests 610 billion tons of Carbon Soils 1580 " " “ " Deep Ocean 38100 " " “ " Permafrost : Permafrost is a solid structure of frozen soil, extending to depths of 2.200 feet in some areas of the arctic and sub arctic regions, containing grasses, roots, sticks, much of it dating back to 30,000 years. About 25% of the land areas of the Northern Hemisphere hold permafrost, which is defined as soil whose temperature has been 32 degrees Fahrenheit (0 degrees Celsius) for a period of at least 2 years. Permafrost is under 85% of Alaska land surface and much of Canada, Scandinavia and Siberia and holds about 14 per cent of the world's carbon. The hard permafrost on which is built homes and other buildings, can, with rising temperatures, turn into a soft material causing subsidence and damage to buildings, electric generating stations, pipelines and other structures. Ground instability would cause erosion, affect terrain, slopes, roads, foundations and more. Tundra : A name very suited to the environs of the arctic and subarctic, tundra means 'treeless plain' in Finnish. The tundra is a biome (a major segment of a particular region having distinctive vegetation, animals and microorganisms adapted to a unique climate), home to about 1700 kinds of plants, including shrubs, mosses, grasses, lichens and 400 kinds of flowers. About 50 billion tons of carbon are estimated to be held in a frozen state in the tundra, and now the tundra is beginning to become a source of carbon dioxide. In the 1970's University of California biologist Walter Oechel studied carbon dioxide emissions in the tundra, which until this time had been thought of as a carbon sink. Doing further tests in the 1980's, Oechel discovered that this was no longer the case, that warming temperatures had changed the tundra to a net emitter of carbon 7
  • 8. dioxide. Says Oechel, " We found to our great surprise that the tundra was already losing carbon dioxide to the atmosphere. So that by the start of these experiments, which was in 1982, the tundra had already warmed and dried enough, that its historic role as a carbon sink had reversed and changed. It was now losing carbon dioxide to the atmosphere. That was totally unexpected." Effect of Global Warming There has been a considerable increase in the average temperature of earth in the past century. This rise in temperature 8
  • 9. is attributed to the effect of warming brought about by the accumulation of greenhouse gases in the atmosphere. This phenomenon is called Global Warming. The effects of global warming are numerous. The main culprits in the issue are excessive discharge of green house gases in the atmosphere. The greenhouse gases trap the heat in the atmosphere and make the earth warm. The greenhouse gases such as carbon dioxide, methane, nitrous oxide, water vapor etc. have increased tremendously in the atmosphere due to the recent industrialization. The excessive deforestation has resulted in further increase of the carbon dioxide in the air. Burning of fossil fuels accumulated in centuries for the purpose of generation of electricity by the power plants has led to great emissions of carbon dioxide. More over the carbon dioxide emissions from the road vehicles have further increased the contents of these green house gases. One of the major effects of global warming is the climatic change that is being absorbed on the earth. There are floods in the areas where the flood history is not very common. There are droughts in places, which were having good rainfall earlier. The atmosphere gets suddenly very harsh in the terms of cyclones and thunderstorms. The nature of earth's atmosphere is becoming even more unpredictable and hence a cause of attention. This in turn brings about a variation in the biological systems essentially the crops, forests, oceans, fresh waterways, and grasslands. As these are the building and breeding grounds of life, the life on earth is getting affected. Another major effect of Global Warming has been noticed in the behavior of the wild life. There has been extinction of various species due to global warming. Major changes are seen in the animals as they react to the warmer environment, which are caused due to global warming. A behavior pattern of the animals studied shows that the animals are beginning to shift their population towards north or towards a higher altitudes. A simple study that was made in the university of California on a small butterfly is enough to depict the changes in the availability of species in the warmer areas. A survey at one hundred and fifty one areas showed that the butterfly were getting less populated in the southern areas which were warmer as compared to the northern areas. Hence the butterflies have migrated from warm southern zone to cooler northern zone. 9
  • 10. The marine life is also very sensitive to the increase in temperatures. The effect of global warming will definitely be seen on some species in the water. A survey was made in which the marine life reacted significantly to the changes in water temperatures. It is expected that many species will die off or become extinct due to the increase in the temperatures of the water, whereas various other species, which prefer warmer waters, will increase tremendously. Perhaps the most disturbing changes are expected in the coral reefs that are expected to die off as an effect of global warming. Even the penguins that live on poles are getting affected as a result of global warming. Due to melting of polar ice their life cycle is getting disturbed and which leads to death of many animals. Another effect of global warming will be on the vegetation that is available on the earth surface. The tundra type of vegetation will turn to temperate, cold deciduous and evergreen type of forest. Woody plant population will tend to increase as a result of increased precipitation. There will be a drastic change in the type of vegetation available in the area, which will in turn effect the inhabitation of the area. As an effect of global warming the glaciers are retreating at an alarming rate and changing the entire environment of the mountains. This will bring about the most intense climatic changes and alteration in the habitat. There will be a considerable increase in the water level of oceans and seas as a result of melting of glaciers. This increase in level of seas and oceans will engulf land at the coastal areas and some low lying countries may even become submerged. As an effect of global warming there are rapid temperature changes expected in the future which will affect the length of the seasons. The winter will be quite short. This will imbalance the ecosystem and will effect greatly on the behavior of the birds and the animals. This will require a drastic change in the feeding periods of young birds and the availability of food for them. These climatic changes will also impact on the growing season for the farmers. The farmers are planting the seeds according to the seasons and rain, but since the rains are getting disturbed and also the climate is getting shifted, the sowing time is difficult to predict, which will lead to poor production and hence shortage of food grains. Much of the crop is also effect by the violent nature of the atmosphere like thunder storms and cyclones. 10
  • 11. As an effect of global warming species like golden toad, harlequin frog of Costa Rica has already become extinct. There are number of species that have a threat of disappearing soon as an effect of global warming. As an effect of global warming various new diseases have emerged lately. These diseases are occurring frequently due to the increase in earths average temperature since the bacteria can survive better in elevated temperatures and even multiplies faster when the conditions are favorable. The global warming is extending the distribution of mosquitoes due to the increase in humidity levels and their frequent growth in warmer atmosphere. Various diseases due to ebola, hanta and machupo virus are expected due to warmer climates. The global warming is expected to cause irreversible changes in the ecosystem and the behavior of animals. The effects of global warming are very large in number and still there are so many that are still to be found out. But recently the problem has become visible and evident due to happening of the events that were before just talked off. Global Warming Kills the Animals Species Disappear : The latest report from the World Conservation Union says that a minimum of 40 percent of the world’s species are being threatened ... and global warming’s one of the main culprits. Cannibalistic Polar Bears : As longer seasons without ice keep polar bears away from food, they start eating each other. ...And Dying Polar Bears : A recent study completed by the U.S. Geological Survey shows that cannibalism—while brutal—may be the least of the bear’s problems. Many are also drowning, unable to swim in the increased spaces between melting sea ice. Two-thirds of them may be gone by 2050. Dying Gray Whales : Save the whales! Global warming is thwarting majestic gray whales’ struggle to recover from their endangered status. In recent years, more gray whales have been 11
  • 12. washing up on beaches after starving to death. Culprit: Rising ocean temps, which are killing off their food supply. Death March of the Penguins : Scientists blame global warming for the declining penguin population, as warmer waters and smaller ice floes force the birds to travel further to find food. “Emperor penguins ... have dropped from 300 breeding pairs to just nine in the western Antarctic Peninsula.” Farewell to the Arctic Fox : The White Arctic Fox used to rule the colder climates, but as temperatures warm up, its more aggressive cousin, the Red Fox, is moving North and taking over. Jellyfish Attack : Ouch! At least 30,000 people were stung by jellyfish along the Mediterranean coast last year; some areas boasted more than 10 jellyfish per square foot of water. Thank global warming: Jellyfish generally stay out of the way of swimmers, preferring the warmer, saltier water of the open seas. Hotter temperatures erase the natural temperature barrier between the open sea and the shore. The offshore waters also become more saline, causing the stinging blobs of hurt to move in toward the coastlines (and your unsuspecting legs). Giant Squid Attack : Giant squid—an “aggressive predator” that grows up to 7 feet long and can weigh more than 110 lbs —used to only be found in the warm waters along the Pacific equator. Hotter waters mean today they’re invading the waters of California and even Alaska. Homeless Sheep, Goats, and Bears : Bighorn sheep, mountain goats, and grizzly bears are becoming homeless, due to the disappearance of the alpine meadows in Glacier National Park. Homeless Deer and Marsh Rabbits : The deer and marsh rabbits in the Florida Keys also face a housing crisis, as water levels rise and warmer temperatures destroy coastal prairies and freshwater marsh habitats. Birds around the World : Recent research found that “up to 72 percent of bird species in northeastern Australia and more than a third in Europe could go extinct due to global warming.” 12
  • 13. Global Warming Kills the Planet Greenland’s Melting : Greenland is melting at a rate of 52 cubic miles per year—much faster than once predicted. If Greenland’s entire 2.5 million cubic kilometers of ice were to melt, it would lead to a global sea level rise of 7.2 meters, or more than 23 feet. Less Ice in the Arctic : The amount of ice in the Arctic at the end of the 2005 summer “was the smallest seen in 27 years of satellite imaging, and probably the smallest in 100 years.” Experts said it’s the strongest evidence of global warming in the Arctic thus far. Ice Shelf in Antarctica Bites the Dust : In 2002, a chunk of ice in Antarctica larger than the state of Rhode Island collapsed into the sea. British and Belgian scientists said the chunk was weakened by warm winds blowing over the shelf ... and that the winds were caused by global warming. Say Farewell to Glaciers : “In Glacier National Park, the number of glaciers in the park has dropped from 150 to 26 since 1850. Some project that none will be left within 25 to 30 years.” The Green, Green Grass of Antarctica : Grass has started to grow in Antarctica in areas formerly covered by ice sheets and glaciers. While Antarctic hair grass has grown before in isolated tufts, warmer temperatures allow it to take over larger and larger areas and, for the first time, survive through the winter. Giant “Sand Seas” in Africa : Global warming may unleash giant “sand seas” in Africa—giant fields of sand dunes with no vegetation—as a shortage of rainfall and increasing winds may “reactivate” the now-stable Kalahari dune fields. That means farewell to local vegetation, animals, and any tourism in the areas. Florida’s National Marine Sanctuary in Trouble : Global warming is “bleaching” the coral in the Florida Keys National Marine 13
  • 14. Sanctuary, killing the coral, tourism, and local fish that live among the coral for protection. The Oceans are Turning to Acid : It sounds like a really bad sci-fi movie, but it’s true: The oceans are turning to acid! Oceans absorb CO2 which, when mixed with seawater, turns to a weak carbonic acid. Calcium from eroded rocks creates a “natural buffer” against the acid, and most marine life is “finely tuned” to the current balance. As we produce more and more CO2, we throw the whole balance out of whack and the oceans turn to acid. Say Goodbye to the Great Barrier Reef : According to the U.N., the Great Barrier Reef will disappear within decades as “warmer, more acidic seas could severely bleach coral in the world-famous reef as early as 2030.” Mediterranean Sea? Try the Dead Sea : Italian experts say thanks to faster evaporation and rising temperatures, the Mediterranean Sea is quickly turning into “a salty and stagnant sea.” The hot, salty water “could doom many of the sea's plant and animal species and ravage the fishing industry.” A Sacred River Dries Up : The sacred Ganges River in India is beginning to run dry. The Ganges is fed by the Gangotri glacier, which is today “shrinking at a rate of 40 yards a year, nearly twice as fast as two decades ago.” Scientists warn the glacier could be gone as soon as 2030. Goodbye to the Mangrove Trees : Next on the global warming hit list: Rising sea levels linked to climate change mean we could lose half of the mangrove trees of the Pacific Isles by the end of the century. More Hurricanes : Over the past century, the number of hurricanes that strike each year has more than doubled. Scientists blame global warming and the rising temperature of the surface of the seas. More Floods : During the summer of 2007, Britain suffered its worst flood in 60 years. Scientists point the finger directly at global warming, which changed precipitation patterns and is now causing more “intense rainstorms across parts of the northern hemisphere.” 14
  • 15. More Fires : Hotter temperatures could also mean larger and more devastating wildfires. This past summer in California, a blaze consumed more than 33,500 acres, or 52 square miles. Thunderstorms Get Dangerous : Hurricanes aside, NASA scientists now say as the world gets hotter, even smaller thunderstorms will pose more severe risks with “deadly lightning, damaging hail and the potential for tornadoes.” Higher Sea Levels : Scientists believe sea levels will be three feet higher by the end of the century than they are now. Global Warming Makes Us Sicker: People Are Dying : 150,000: Number of people the World Health Organization estimates are killed by climate-change- related issues every year. Heat Waves and Strokes : Authorities in China say warmer temperatures are responsible for an up tick in heat-wave associated deaths, such as strokes and heart disease. They calculated between 173 and 685 Chinese citizens per million die every year from ailments related to global warming. Death by Smog : Three words you really don’t want in your obit: “Death by Smog.” Yet Canadian doctors say smog-related deaths could rise by 80 percent over the next 20 years. And since warm air is a key ingredient in smog, warmer temperatures will increase smog levels. More Heart Attacks : Doctors warn global warming will bring more cardiovascular problems, like heart attacks. “‘The hardening of the heart's arteries is like rust developing on a car,’ said Dr. Gordon Tomaselli, chief of cardiology at Johns Hopkins University. ‘Rust develops much more quickly at warm temperatures and so does atherosclerosis.’” More Mold and Ragweed = More Allergies, Asthma : A Harvard Study in 2004 showed higher concentrations of CO2 in the atmosphere is good news to allergens like mold and ragweed (they love the stuff). And that means higher rates of asthma attacks, especially in kids. 15
  • 16. A Resurgence In Deadly Disease : “The World Health Organization has identified more than 30 new or resurgent diseases in the last three decades, the sort of explosion some experts say has not happened since the Industrial Revolution brought masses of people together in cities.” Why? Global warming “is fueling the spread of epidemics in areas unprepared for the diseases” when “mosquitoes, ticks, mice and other carriers are surviving warmer winters and expanding their range, bringing health threats with them.” Spread of Dengue Fever : Scientists predict warmer temperatures will allow mosquitoes carrying Dengue Fever to travel outside the tropics. Since people in cooler climes lack immunity from previous exposure, that means transmission would be extensive. You get a severe fever, you start spontaneously bleeding, you can die. There is no vaccine. Death in the Time of Cholera : Cholera, which thrives in warmer water, appeared in the newly warmed waters of South America in 1991 for the first time in the 20th century. “It swept from Peru across the continent and into Mexico, killing more than 10,000 people.” Global Warming Threatens Our National Security Starvation : A study by IISS found that reduced water supplies and hotter temperatures mean “65 countries were likely to lose over 15 percent of their agricultural output by 2100.” Large-Scale Migrations : Global warming will turn already-dry environments into deserts, causing the people who live there to migrate in massive numbers to more livable places. More Refugees : A study by the relief group Christian Aid estimates the number of refugees around the world will top a billion by 2050, thanks in large part to global warming. Increased Border Tensions : A report called “National Security and the Threat of Climate Change,” written by a group of retired generals and admirals, specifically linked global warming to increased border tensions. “If, as some project, sea levels rise, 16
  • 17. human migrations may occur, likely both within and across borders.” Famine : “Developing countries, many with average temperatures that are already near or above crop tolerance levels, are predicted to suffer an average 10 to 25 percent decline in agricultural productivity by the 2080s.” Droughts : Global warming will cause longer, more devastating droughts, thus exacerbating the fight over the world’s water. The Poor Are Most at Risk : Although they produce low amounts of greenhouse gases, experts say under- developed countries—such as those in sub-Saharan Africa—have “the most to lose under dire predictions of wrenching change in weather patterns.” QUESTIONAIRE What is global warming? Global warming is the rise in temperature of the earth's atmosphere. It's said that by the time a baby born today is 80 years old, the world will be 6 and a half degrees warmer than it is now. Is global warming bad? 17
  • 18. The earth is naturally warmed by rays (or radiation) from the sun which pass through the earth's atmosphereand are reflected back out to space again. The atmosphere's made up of layers of gases, some of which are called 'greenhouse gases'. They're mostly natural and make up a kind of thermal blanket over the earth. This lets some of the rays back out of the atmosphere, keeping the earth at the right temperature for animals, plants and humans to survive (60DegF/16DegC). So some global warming is good. But if extra greenhouse gases are made, the thermal blanket gets thicker and too much heat is kept in the earth's atmosphere. That's when global warming's bad. What are the greenhouse gases? Greenhouse gases are made out of: • water vapour • carbon dioxide • methane (come from animal poo) • nitrous oxide • ozone • chlorofluorocarbons (CFCs) They are all natural gases, but extra greenhouses gases can be made by humans from pollution. How are extra greenhouse gases produced?ss Extra greenhouse gases are produced through activities which release carbon dioxide, methane, nitrous oxide and ozone CFCs (chlorofluorocarbons). These activities include: 18
  • 19. • Burning coal and petrol, known as 'fossil fuels' • Cutting down of rainforests and other forests • Animal waste which lets off methane What's the 'ozone layer' got to do with global warming? The ozone layer is another important part of the atmosphere. It's made up of ozone (a type of oxygen) that protects the earth from too many harmful rays called UVB. So.... what could happen ? If Earth gets hotter, some of the important changes could happen: • Water expands when it's heated and oceans absorb more heat than land, so sea levels would rise. • Sea levels would also rise due to the melting of the glaciers and sea ice. • Cities on coasts would flood. • Places that usually get lots of rain and snowfall might get hotter and drier. • Lakes and rivers could dry up. • There would be more droughts making hard to grow crops. • Less water would be available for drinking, showers and swimming pools. • Some plants and animals might become extinct because of the heat. • Hurricanes, tornadoes and other storms which are caused by changes in heat and water evaporation may get more common. What's being done about it? 19
  • 20. The United Nations has meetings where world leaders agree on what to do about global warming. Every five years, the Earth Summit happens. In 1997 there was an Earth Summit in Rio de Janeiro and in 1997, an agreement was made at the UN Conference on Climate Change in Kyoto, Japan, to cut the amount of gases that industries make. Leaders agree the world can cut the amount of carbon dioxide that's released into the atmosphere by changing the way power is produced too. What can U do? There are ways you can help cut greenhouse gases and help stop global warming. They are simple things, but can make a difference if everyone does them!  Re-cycle glass bottles, jars, newspapers and magazines and tin cans. Save them and take them to local re-cycling centers.  Re-use plastic shopping bags and envelopes, don't get new ones  Persuade you mum or dad (or whoever does the gardening) to have a compost heap.  Put a brick in a plastic bag into your toilet cistern, then the toilet will use less water each time you flush. Don't worry that's plenty of water to get rid of...  Use paper on both sides.  Try and buy products that don't use much packaging.  Give unwanted gifts and clothes to a charity shop.  Only fill the kettle up with the amount of water you need to boil that time.  Don't leave the TV or video on standby. 20
  • 21.  If you get lift to office in a car, take your mates along for the ride.  Ask whoever does your washing to use the machine at 40 degrees, this helps conserve power.  Switch lights off when you're not in the room.  Get a clockwork mobile phone recharger / if not available locally. Take out the charger from the power socket when it’s not being used.  Cycle to places!  Have showers instead of baths…or if you really care. Other ways of making green energy  Gas produced from rotting rubbish on landfill sites could be used  An example; www.projectsimilipal.blogspot.com  Experts are also looking at energy crops; sugarcane is being used to produce ethanol,. as a green fuel.  Small scale and domestic solar energy are being developed. Most of the above said stuff is from BBC. That’s the basics. Given below are some details about the same facts- in a slightly more scientific way; Burning fossil fuels, and the consequent release of carbon dioxide, is highly essential to our day-to-day activities. But, the increased quantity and speed at which these gases are released into the atmosphere is threatening the earth’s climate. This increase in atmospheric concentrations of carbon dioxide and other greenhouse gases released by human activities, such as burning fossil fuels and deforestation, play a major role in warming the Earth. This phenomenon, known as global warming, is likely to raise sea levels by expanding ocean water, and by melting glaciers and the polar ice cap. The U.S. Environmental Protection Agency (EPA) reported recently that the 20th century was the hottest of the last one thousand years. Six of the 10 warmest years ever recorded were in the 1990s; the other four were in the 1980s. Europe's winter is now 11 days shorter than it was 35 years ago. The 21
  • 22. Arctic ice cover is at the same time shrinking by an area the size of the Netherlands each year. Further south, Europe's largest glacier, the Breidamerkurjoll in Iceland, is expected to slide into the Atlantic within five years. In the last 100 years, the sea level has already risen by about 7 inches, wiping up miles of land, and it is expected to rise more in the future leading to the actual submergence of islands. By the year 2080, Manhattan and Shanghai could be underwater. Moreover, storms, droughts, and floods could become more extreme than they already are, and this is also attributed to the emissions of greenhouse gases (GHGs). As a matter of fact, climate change is considered to be the most serious threat to the world's environment, affecting human health, food security, economic activity, natural resources, and physical infrastructure. Unless curbed, global warming is to be the fatal catastrophe of our era. Global Warming: Causes and Solutions Although greenhouse gases are natural gases that maintain the earth's temperature, an excess of those gases, resulting from human activities, raises the temperature in the atmosphere and leads to global warming. So what are the human activities that release greenhouse gases? 1. Burning fossil fuels to produce electricity, power factories, and to carry out a wide range of vital human tasks. The use of fossil fuels accounts for three fourths of manmade carbon dioxide emissions. 2. Deforestation: Deforestation results in an increase of atmospheric carbon dioxide as forests normally absorb this greenhouse gas in the course of photosynthesis. 22
  • 23. 3. Accumulation of animal manure, which lets off methane- another greenhouse gas. Methane is emitted from the manure during storage in lagoons or concrete tanks. Putting a stop to the process of global warming may be achieved simply through reducing the emissions of greenhouse gases that cause the greenhouse effect. Industrialized countries that have spent decades enhancing their industries and polluting the planet should be held accountable by establishing environmentally friendly systems that cut the use of fossil fuels and release smaller amounts of greenhouse gases. ACKNOWLEDGEMENT We, the members of Group 3, would like to take this opportunity to thank Prof. Mathew for giving us an interesting topic for our presentation, on Global Warming. This presentation has helped us to gain the maximum knowledge of the same. It has helped us to learn about the effects and causes of Global Warming and also about some of the preventive steps that could be taken to avoid all the ill-effects. 23
  • 24. This will surely be helpful to us in our near future. BIBLIOGRAPHY We got our information from the following sites: -  WWW.GOOGLE.COM  WWW.YAHOO.COM  WWW.DOGPILE.COM  WWW.WIKIPEDIA.COM 24

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