http://en.wikipedia.org/wiki/G lobal_warming.....plz click this site and u'll get much information

Answered by puja sethi , an ibibo Citizen, at 5:43 PM on October 05, 2008

Global Warming :
It can be defined as the increase in the mean temperature of the earth due to excessive emissions of greenhouse gases such as carbon dioxide, methane, and nitrogen. Most scientists now believe that, unchecked, global warming will produce disastrous climate changes over the next 100 years.

Causes for Global Warming :
Global warming is caused by several causes such as pollution from factories, carbon dioxide from rotting trees, the burning of coal, natural gasses and fossil fuels lead to methane travelling into the Earth's atmosphere any transportation vehicles, water vapour, and many other little things, which contribute to make global warming even worse.

Effects of Global Warming :
Due to the global warming increasing, glaciers will get melt and the ocean level will rise up and that will create catastrophic changes & disasters on the earth.

What we can do to decrease the global warming :
Some of the actions which we all have to take will slightly decrease your present standards of living.
First, since the largest portion of electricity in the US is produced by burning coal, we should try to cut-down on our demand for electricity. Coal combustion creates the largest amount of CO2 per energy unit of any fossil fuel. Coal and oil together represent 80% of the US fuel supply used to generate electricity. When we reduce electric power use, we save money, breathe cleaner air, and help to reduce the global warming problem. Every kilowatt-hour of electricity saved keeps 1.5 to 2 pounds of CO2 out of the atmosphere. Americans waste more energy than any other nation. I believe it is time to make our lives, factories, and homes more efficient. Look around at home, and at your work place, and you will find several ways in which you can decrease the use of electricity. For instance, plant several trees on the south side of your house where they can give shade during the hot summer months. Also, install an energy efficient thermostat, with a day and night timer.

I think for a 8th standard school boy, this details is enough. Convey to your son that i wished him for his success in studies. Take Care. Have a nice day.

Answered by Thiyaga Raj , an ibibo Specialist, at 5:06 PM on October 05, 2008

This article is about the current period of increasing global temperature. For other periods of warming in Earth's history, see Paleoclimatology and Geologic temperature record.

Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation.

The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005.[1] The Intergovernmental Panel on Climate Change (IPCC) concludes "most of the observed increase in globally averaged temperatures since the mid-twentieth century is very likely due to the observed increase in anthropogenic (man-made) greenhouse gas concentrations"[1] via an enhanced 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.[2][3]
Global mean surface temperature anomaly relative to 1961–1990
Global mean surface temperature anomaly relative to 1961–1990

These basic conclusions have been endorsed by at least 30 scientific societies and academies of science,[4] including all of the national academies of science of the major industrialized countries.[5][6][7] While individual scientists have voiced disagreement with some findings of the IPCC,[8] the overwhelming majority of scientists working on climate change agree with the IPCC's main conclusions.[9][10]

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 twenty-first century.[1] This 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.[1]

Increasing global temperature is expected to cause sea levels to rise, an increase in the intensity of extreme weather events, and significant changes to the amount and pattern of precipitation, likely leading to an expanse of tropical areas and increased pace of desertification. Other expected effects of global warming include changes in agricultural yields, modifications of trade routes, glacier retreat, mass 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.

Answered by Raghunath , an ibibo Citizen, at 11:22 AM on October 05, 2008

Global Warming: Global warming refers to an average increase in the Earth's temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. When scientists talk about the issue of climate change, their concern is about global warming caused by human activities.

Global warming is the increasing since the mid-20th century, and its projected continuation.most of the observed increase in globally averaged temperatures are very likely due to the observed increase in man-made greenhouse gas concentrations via an enhanced greenhouse effect.Greenhose effect:-Green·house Ef·fect The effect produced as greenhouse gases allow incoming solar radiation to pass through the Earth's atmosphere, but prevent most of the outgoing infrared radiation from the surface and lower atmosphere from escaping into outer space. This process occurs naturally and has kept the Earth's temperature about 60 degrees Fahrenheit warmer than it would otherwise be. Current life on Earth could not be sustained without the natural greenhouse effect.
The greenhouse effect is important. Without the greenhouse effect, the Earth would not be warm enough for humans to live. But if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.
It's effect:-
Average global temperature has increased by almost 1ºF over the past century; scientists expect the average global temperature to increase an additional 2 to 6ºF over the next one hundred years. This may not sound like much, but it could change the Earth's climate as never before. At the peak of the last ice age (18,000 years ago), the temperature was only 7ºF colder than it is today, and glaciers covered much of North America!
Even a small increase in temperature over a long time can change the climate. When the climate changes, there may be big changes in the things that people depend on. These things include the level of the oceans and the places where we plant crops. They also include the air we breathe and the water we drink.
Ecological Systems
Climate change may alter the world's habitats and ecosystems – all living things are included in and rely on these places. Many of these places depend on a delicate balance of rainfall, temperature, and soil type. A rapid change in climate could upset this balance and seriously endanger many living things.
Most past climate changes occurred slowly, allowing plants and animals to adapt to the new environment or move somewhere else. However, if future climate changes occur as rapidly as some scientists predict, plants and animals may not be able to react quickly enough to survive. The ocean's ecosystems also could be affected for the same reasons.
Sea Level Rise
Global warming may make the sea level become higher. Why? Well, warmer weather makes glaciers melt. A glacier is a large sheet of ice that moves very, very slowly. Some melting glaciers add more water to the ocean. Warmer temperatures also make water expand. When water expands in the ocean, it takes up more space and the level of the sea rises.
Sea level may rise between several inches and as much as 3 feet during the next century. This will effect both natural systems and manmade structures along coastlines. Coastal flooding could cause saltwater to flow into areas where salt is harmful, threatening plants and animals in those areas.
Crops and Food Supply
Global warming may make the Earth warmer in cold places. People living in these places may have a chance to grow crops in new areas. But climate change also might bring droughts to other places where we grow crops. In some parts of the world, people may not have enough to eat because they cannot grow the food that they need.

How to prevent it?
1)S

Answered by Aprajita , an ibibo Citizen, at 9:53 AM on October 05, 2008