A Better Place for People to Live

Because of man's misbehaviour the Earth is getting warmer. This is called the greenhouse effect. The greenhouse effect causes global warming.
The main problem is the release of carbon dioxide. Carbon dioxide traps infra-red rays.
Vehicles, factories, planes, rockets, ships and power stations release carbon dioxide and gases such as carbon monoxide, nitrogen dioxide and methane. These gases can cause cancer and other diseases. They also produce acid rain which can harm life of all kinds.
When the Earth warms glaciers and ice packs melt so the sea level rises. Islands may disappear making people homeless. But in other places lakes, rivers and tanks become dry so people don't have enough water.
If we want to prevent global warming we have to grow more trees. Trees can absorb carbon dioxide and release oxygen. We shouldn't release poisonous gases from factories, vehicles, planes and power stations. We can build factories in areas where people don't live. We can use refrigerators and sprays that don't release CFCs. We can make laws to restrict emissions from factories and vehicles. If we recycle garbage we will also help the environment

We have to protect the environment and make it a better place for the people to live.
UDESHIKA

Environmental Pollution

Humans first started using fire many, many centuries ago. However, air pollution first became a major problem during the 18th and 19th centuries during the Industrial Revolution.

Excessive production of CFCs has depleted the stratospheric ozone layer, creating a hole above Antarctica. As a result exposure to the sun's harmful rays has damaged aquatic and terrestrial life.

Water is necessary for life on earth. All organisms contain it, some live in it, all drink it. Water pollution can kill large numbers of fish, birds and other animals. People throw their garbage into rivers, lakes and the sea. Because of this the world will lose lots of species.

Unwanted sound or noise such as that produced by airplanes, traffic or factories is also a form of pollution. Noise pollution is at its worst in densely populated areas. It can cause hearing loss. Long lasting, high intensity are the worst and can cause serious problems with stress. Solutions for noise pollution include: insulation and soundproofing to doors, walls and ceilings; using ear protection particularly in industrial working areas; arranging plants and vegetation to absorb and screen out noise; and zoning urban areas to separate residential from industrial areas.

Environment is the gift of god. We must protect the environment as our mother.
HANSANI

The Ozone, CFCs and Global Warming

There have been many natural disasters: Tsunami, storms, earthquakes, floods, cyclones, hurricanes and eartquakes. Some scientists believe that global warming is the cause of may of these. October 16 was declared Ozone (global warming) Day.

The Earth has an ozone layer 10-50km from the Earth's surface. It converts the sun's radiation [the solar flux density is 1353 W/m2] to heat energy. It prevents many harmful rays such as cosmic rays (99%), ultra-violet rays (78%)and infra-red rays(4%). As a result the Earth receives more energy from the sun as electro-magnetic radiation.

The earth's surface absorbs solar energy and releases it back into the atmosphere as as infra-red radiation, some of which goes back into space (about 50%).

There are many gases in our atmosphere that contribute to global warming CO2 (burning of carbon fuels), CH4 (anaerobic bacteria), N20 (fossil fuel and fertilisers), CFC/CFC3 (refrigerators and sprays), SF6, S02, CH3SF3, CH2 and CO(vehicle fumes).

CFC, carbon tri-chloro fluoro and SF6 absorb heat very efficiently and are critical components in the greenhouse effect. These gases absorb the infra-red radiation emiited by the Earth and re-radiate the energy as heat back to the Earth causing greenhouse effect warming.

Ozone holes were discovered by scientists at the British Antarctic Survey over 20 years ago. The Montreal Agreement in 1987 agreed to ban CFCs.

The collection of meteorological data from observation satellites and samples taken from glaciers and trees confirms what many of us already know - the globe is warming up. It is generally agreed that by 2030/40 average global temperatures will have risen by 5degC causing ice caps and glaciers to melt and sea levels to rise. Failure to take action carries a dangerous risk.

As debates continue amd governments fail to act it is becoming more likely that we will be able to see for ourselves whether the dire predictions have been overstated by the middle of this century.

PARANEETHARAN

Global Warming & Global Dimming

Environmental pollution is going to have a big impact on our lives. We will have to face the effects of global warming and global dimming in the future.

The greenhouse effect is the main reason for global warming. The greenhouse effect refers to the change of the temperature of the Earth by the gases contained in the atmosphere. These gases are called "greenhouse gases". They absorb and emit infra-red radiation. Greenhouse gases include water vapour, carbon dioxide and methane. They warm the atmosphers by absorbing thermal infra-red radiation emitted by the Earth's surface. They also emit radiation in all directions, including downwards to the Earth's surface. As a result, the temperature of the Earth's surface will rise.

Global dimming is also a challenge to us. Global dimming refers to the gradual reduction in the amount of global direct sunlight. The gases emitted from vehicles, factories and power stations are the main reason for global dimming. They cover the atmosphere in a layer. They absorb solar energy and reflect sunlight back into space. So the amount of direct sunlight decreases. This will have a disastrous impact on trees and vegetation. The decreasing density of the ozone layer allows harmful ultra-violet rays to penetrate the atmosphere. This can cause skin cancer and more global warming.
MILINDA

A Comfortable Earth

Global warming is a serious problem which is getting worse. The main cause is human activity which releases greenhouse gases. When the greenhouse gases are released into the environment they form a layer which holds the temperature in. Infra-red rays which enter the layer cannot escape.
The main gas in the layer is CO2. Trees absorb CO2, so if we cut trees down the CO2 percentage increases.If this process continues mountains of ice will melt and the sea level will rise. Islands like the Maldives will disappear. So we should look to solutions like forest protection, alternative fuels and a ban on the emission of harmful gases from factories and power stations.
If we do these things the Earth will be a more comfortable place to live.
DHANUSHKA