PPT ON GLOBAL WARMING

SUBMITTED TO:RUPINDER MA’AM

SUBMITTED BY:CHAHATPANDEY

AN ATTEMPT.....To make people aware about consequences of global warming.

GLOBAL WARMING( A Threat To Environment)

All across the world, in every kind of environment and region known to man, increasingly dangerous weather patterns and devastating storms are abruptly putting an end to the long-running debate over whether or not climate change is real. Not only is it real, it's here, and its effects are giving rise to a frighteningly new global phenomenon: the man-made natural disaster.

CONTENTSWhat is Global WarmingGreenhouse EffectCauses of global warmingRise in sea levelOzone layer depletionForest cover depletionEffects on ecological system(Humans,

Marine Lives)Islands/peninsular danger of being submergedConclusionThank You

What Is Global Warming?.

Global warming is the rising average temperature of Earth’s atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's average surface temperature has increased by about 0.8 °C (1.4 °F), with about two thirds of the increase occurring since 1980. Warming of the climate system is unequivocal, and scientists are more than 90% certain that most of it is caused by increasing concentrations of greenhouse gases produced by human activities such as deforestation and the burning of fossil fuels. These findings are recognized by the national science academies of all major industrialized nations.

The 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 and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases.

GREEN HOUSE EFFECT

Earth’s natural greenhouse effect makes life as we know it possible. However, human activities, primarily the burning of fossil fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming.

NATURAL ORIGIN OF GLOBALWARMING

MANMADE ORIGIN OF GLOBAL WARMINGPOLLU

TION

DEFORESTATION

RESOURCE MISEXPLOI

TATION

OVERPOPULATION•EXESS VECHICLE USE

BURNING OF FOSSIL

FEULS

Scientists say that the barrier insulating the continental ice caps is melting. “The impacts of warming temperatures in Antarctica are likely to occur first in the northern sections of the continent, where summer temperatures approach the melting point of water, 32 degrees F (0 degrees C).”

What’s happening

As the ice melts, big chunks of glaciers will break off and become like ice cubes in a big glass of water. The ice chunks, known as icebergs, create mass in the ocean. The icebergs displace the water causing the ocean level to rise. Some of the shoreline in many places like Florida (where the land is at a low altitude) will go under water.

What’s

happening

At present, sea levels around the world are rising. Current sea level rise potentially impacts human populations (e.g., those living in coastal regions and on islands)and the natural environment (e.g., marine ecosystems).Global average sea level rose at an average rate of around 1.7 ± 0.3 mm per year over 1950 to 2009 and at a satellite-measured average rate of about 3.3 ± 0.4 mm per year from 1993 to 2009, an increase on earlier estimates. It is unclear whether the increased rate reflects an increase in the underlying long-term trend.

RISE IN SEA LEVEL

OZONE 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 tropospheric ozone depletion events.

CFCs 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,[3] 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.

Contd..

Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use.The term deforestation is often misused to describe any activity where all trees in an area are removed. However in temperate climates, the removal of all trees in conformance with sustainable forestry practices—is correctly described as regeneration harvest. In temperate mesic climates, natural regeneration of forest stands often will not occur in the absence of disturbance, whether natural or anthropogenic. Furthermore, biodiversity after regeneration harvest often mimics that found after natural disturbance, including biodiversity .

DEFORESTATION

Global warming is caused by the emission of greenhouse gases . 72% of the totally emitted greenhouse gases is carbon dioxide (CO2). Therefore CO2 emissions are the most important cause of global warming .CO2 is created by burning fossil fuels like e.g. oil, natural gas, diesel. The emissions of CO2 have been dramatically increased within the last 50 years and are still increasing (CO2 emissions by country).Carbon dioxide remains in the atmosphere for 80 to 200 years. According to recent investigations, unimaginable catastrophic changes in the environment are expected to take place if the global temperatures increase by more than 2° C (3.6° F). A warming of 2° C (3.6° F) corresponds to a carbon dioxide (CO2) concentration of about 450 ppm (parts per million) in the atmosphere. The current (year 2007) concentration of CO2 is at about 380 ppm and it is currently increased by 2 to 3 ppm each year.

RISE IN CO2 CONC. IN ATMOSPHERE

The world-wide emissions of CO2 for the year 2006 was about 28 billion tonnes. What would happen if we froze the world-wide emissions of carbon dioxide to the current level? Could global warming be mitigated? For this purpose, we simulate a constant emission of 30 billion tonnes of carbon dioxide per year. The blue curve again shows the effect on the average temperature increase. The increase is less steep than in the example above, but the red zone with temperature increases of more than 2 C is still reached. Devastating effects on our environment can be expected to start around the year 2075.

WORLD WIDE EFFECT

“Penguin population decline. Adeliepenguin populations have shrunk by 33 percent during the past 25 years in response to declines in their winter sea ice habitat.”

What’s happening to animals

“Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxantheallae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within scleractinian corals. Coral reef bleaching is caused by various anthropogenic and natural variations in the reef environment including sea temperature, solar irradiance, sedimentation, xenobiotics, subaerial exposure, inorganic nutrients, freshwater dilution, and epizootics. Coral bleaching events have been increasing in both frequency and extent worldwide in the past 20 years. Global climate change may play a role in the increase in coral bleaching events, and could cause the destruction of major reef tracts and the extinction of many coral species.”

                                                       

What’s happening to the animals

Global warming is not something whose effects will be felt centuries later, it is already affecting our lives. The recent scorching weather is not purely an act of nature. Neither is the increasingly volatile weather that is wreaking havoc in certain parts of the globe. Humans are causing global warming and we are suffering as a result, and the consequences will only get heavier.The increased temperatures are not only melting icebergs and glaciers, it is also causing animals to migrate to different areas or die, upsetting ecosystems, and it is also changing precipitation patterns.

IntroductionWhat’s happening to

humans

Melting of polar ice caps and flooding

The effects of global warming are strongest at the poles. Ice all over the world is melting. This includes the ice on mountain glaciers, Arctic sea ice and ice sheets covering West Antarctica and Greenland. The melting ice increases the sea level and this causes flooding of low-lying areas. When snow and ice melt, their ability to reflect sunlight is lost, escalating global warming even further.

Irregular Weather patterns Irregular weather patterns have an effect on humans. Rain is not only an inconvenience for humans, but storms damage human property. The increase in heat will increase evaporation which is why there will be more rain. Animals and plants cannot easily adapt to increased rainfall or snowfall and many animals migrate to other areas. Plants can die as a result and this can cause an ecosystem to collapse as plants are the main source of food in an ecosystem.

The world has had a food crisis and global warming may have been to blame for it. At the moment global warming does not have much of an impact on this, but in the future, there will be impacts.As temperatures around the world will increase, plants will find it harder to cope and they will die. Some of these plants are used by humans for food and so a food shortage may occur. Plants create food for themselves through a process called photosynthesis. The enzymes that are needed for photosynthesis die when exposed to high temperatures. Pests may also migrate to new areas and destroy the crops there. Pests may migrate from tropical countries to temperate countries.

Changes in Food Production

Human HealthRising temperatures have an effect on the health of humans and the diseases that they are exposed to.Human health will be affected. The world glimpsed this in 2003 when Europe was struck by heat waves and people died. Heat strokes are likely to increase as temperatures get hotter.Diseases such as malaria are likely to spread. Parasites that originate in tropical regions may migrate to temperate regions as they become warmer. Mosquitoes are an example and it is predicted that malaria will spread around the world. It is also predicted that asthma will increase around the world as allergens that cause asthma will become more common.

Rising seas, caused by global warming, have for the first time washed an inhabited island off the face of the Earth. The obliteration of Lohachara island, in India's part of the Sundarbans where the Ganges and the Brahmaputra rivers empty into the Bay of Bengal, marks the moment when one of the most apocalyptic predictions of environmentalists and climate scientists has started coming true.As the seas continue to swell, they will swallow whole island nations, from the Maldives to the Marshall Islands, inundate vast areas of countries from Bangladesh to Egypt, and submerge parts of scores of coastal cities.

Islands in danger of being submerged

Eight years ago, as exclusively reported in The Independent on Sunday, the first uninhabited islands - in the Pacific atoll nation of Kiribati - vanished beneath the waves. The people of low-lying islands in Vanuatu, also in the Pacific, have been evacuated as a precaution, but the land still juts above the sea. The disappearance of Lohachara, once home to 10,000 people, is unprecedented.It has been officially recorded in a six-year study of the Sunderbans by researchers at Calcutta's Jadavpur University. So remote is the island that the researchers first learned of its submergence, and that of an uninhabited neighboring island, Suparibhanga, when they saw they had vanished from satellite pictures.

CONTD..

Human cost of global warming: Rising seas will soon make 70,000 people homeless Refugees from the vanished Lohachara island and the disappearing Ghoramara island have fled to Sagar, but this island has already lost 7,500 acres of land to the sea. In all, a dozen islands, home to 70,000 people, are in danger of being submerged by the rising seas.

Two-thirds of nearby populated island Ghoramara has also been permanently inundated. Dr Sugata Hazra, director of the university's School of Oceanographic Studies, says "it is only a matter of some years" before it is swallowed up too. Dr Hazra says there are now a dozen "vanishing islands" in India's part of the delta. The area's 400 tigers are also in danger.Until now the Carteret Islands off Papua New Guinea were expected to be the first populated ones to disappear, in about eight years' time, but Lohachara has beaten them to the dubious distinction

Endangered Wa l rus Drowning Island

St rugg l ing Car Surv ived Luck i l y

Global warming is affecting plants, animals, humans and the earth. We need to learn how to conserve our use of fossil fuels to minimize carbon dioxide production. This will slow down the effects of global warming. Before its too late……..

CONCLUSION