presentation saving our environment

CONSERVATION

This Earth serves not only as our one and only habitat in this universe but it is also our natural heritage as it is passed on from one generation to the next.

The next generation of human beings shall inherit this earth in the condition that we leave it. What our future children will have will depend directly on this generation of ours and hence it is our responsibility and duty to care for the environment today.

Many people do not realise the importance of looking after this fragile environment of ours. They take many things for granted and never think of conserving some of the natural resources we have today. They also think that the resources we have will never run out and we can continuously draw resources from the earth to make our lives easier and more comfortable.

Environmental problems such as depletion of natural resources, water pollution and global warming have all resulted mainly from human activities. However, not all is lost, as we can still do our part for the earth through environmental conservation.

Environmental conservation is the careful use of natural resources to ensure that there is enough for the future and ensuring that damage done to the environment will be minimum.

Conservation also involves minimising the negative impacts caused by environmental problems. For example, CFCs have caused the depletion of the ozone layer. We may not be able to close this hole up but we can stop it from growing bigger by reducing the amount of CFCs released into the atmosphere.

GLOBAL WARMING

Global warming is caused by the greenhouse effect.

Global Warming

Global warming refers to an average increase in the Earth's temperature, which in turn, causes climate change. A warmer earth may lead to changes in rainfall patterns, a rise in sea level and a huge impact on plants, wildlife and humans. Climate change usually refers to global warming that is the result of human activities.

The Greenhouse Effect

The greenhouse effect is a natural process that keeps the Earth warm. It is caused by a layer of gases that traps heat energy from the Sun. This layer of gases is made up of water vapour, carbon dioxide, nitrous oxide and methane, which are called the greenhouse gases.

As heat energy reaches the Earth, some of it is absorbed, and some of it is reflected into space. However, some of the reflected heat is trapped in the atmosphere by the blanket of greenhouse gases.

Diagram courtesy of the EPA

The greenhouse effect is vital for the survival of humans. Without the greenhouse effect, temperatures on Earth could drop by about 33 degrees Celcius/60 degrees Fahrenheit. However. if the greenhouse effect becomes stronger, it could make the Earth hotter than usual. This extra warming may cause climate change, which would be a great problem for humans, animals and plants.

Scientists have deduced that human activities in the main reason why there is an increase in global temperature. Industries, vehicles, farms and dumps are all sources of greenhouse gases. These activities are known to produce a lot of carbon dioxide, methane and nitrous oxides. These gases intensify the greenhouse effect and result in a warmer Earth.

What are the effects of global warming?

Scientists do not know for sure what the effects of global warming are, but there are a few possibilities.

Firstly, there might be more cases of heat stress and other heat related problems, caused by very warm temperatures and high humidity.

Climate change may also alter the world's habitats and ecosystems, which depend on a delicate balance of rainfall, temperature and soil type. A rapid change in climate would upset this balance and there would not be enough time for plants and animals to adapt and survive.

Humans would be greatly affected by this, as humans depend very much on the animals and plants for food. If they die, humans would definitely die, too.

Another popular prediction is that sea levels would rise globally. This is based on the belief that the ice near the Poles would melt and add more water to the oceans. Water would also expand and take up more space, due to more heat. Altogether, these would cause sea levels to rise. The rise in sea level would cause coastal flooding and beach erosion.

POLLUTION

Pollution is the process whereby various harmful substances are added to the environment (land, water, air etc.) by human and natural activities.

The various types of pollution that exist are:

* air pollution
* water pollution
* land pollution
* noise pollution

Natural activities that cause pollution are, for example, volcanic eruptions, sandstorms and natural forest fires. These events cause a large amount of substances such as ash and dust, which are harmful to our health, to be added to the environment.

Although some natural events may contribute to pollution, human activities have a more harmful impact to the environment.

How do humans contribute to pollution?

As the world population increases rapidly, there is an increasing demand for food, materials and energy. The activities that produce these products tend to pollute the environment.

DOMESTIC ACTIVITIES
Homes and offices produce a lot of rubbish and sewage every day.

INDUSTRIAL ACTIVITIES
Some by-products of industries are highly hazardous e.g. sulphur dioxide.

AGRICULTURAL ACTIVITIES
Farms, too, produce a lot of waste. Waste from animals, pesticides and herbicides are washed into rivers and then into the sea.

How does pollution affect our environment?

Pollution has adverse effects on all living and non-living things.

Some of these effects are:

EFFECTS ON MAN
Air pollution can cause breathing problems and eye, throat and skin irritation. When solid waste is not properly treated and disposed of, it can become a breeding for pests and disease can spread.

EFFECTS ON PLANTS
Leaves find it difficult to manufacture food in polluted air. When trees begin to lose their leaves, they may eventually die. When there is too much chemical content in the water absorbed by the roots, it can also affect plant life.

EFFECTS ON ANIMALS
Oil spills in the seas and oceans result in birds and animals (e.g. penguins and seals) being coated in oil. This makes it difficult for them to float and keep warm and they may eventually die. Solid waste in the water encourages the growth of algae which depletes water of oxygen and kills marine life.

EFFECTS ON BUILDINGS
Air pollution discolours and corrodes buildings and statues, e.g. the Louvre Museum in France, historical buildings in London and the Taj Mahal in India are all covered with a layer of pollutants.