Deforestation

One of the country's environmental problems is the rapid rate at which trees are cut down. Did you encounter the same problem in your community? In the Philippines, the major causes of deforestation are:

• Kaingin farming

• Illegal logging

• Conversion of agricultural lands to housing projects

• Forest fires

• Typhoons

As a consequence of cutting down trees, the following effects could take place:

• Decrease in wildlife resources that will eventually lead to extinction

• Soil erosion

• Floods

WILDLIFE DEPLETION

As human population gets bigger, huge space is needed for shelter, for growing crops, and for industries. Deforestation is one of the major causes of the disappearances of wildlife species. What happens to animal populations that are driven away from their natural habitat? If they cannot find enough space, many will die or become extinct. Some species may become endangered, or in the verge of becoming extinct. In other cases, some animals may be threatened, referring to species that are close to being endangered.

Water Pollution

A major problem in lakes, rivers and ponds is eutrophication. It happens when the concentration of organic nutrients that comes from domestic garbage are thrown in bodies of water, increases rapidly one of the effects of water pollution. It is supposed to be a slow process, but man's activities hasten it up. Figure 10 shows the causes and stages of eutrophication in a lake.

Another effect of water pollution is mass death of fish or 'fish kill'. Have you read articles from the newspapers about 'fish kill' in Manila Bay or some other places? Have you seen such an event in your area?

A 'fish kill' usually happens when there is an increase in concentration of organic nutrients in bodies of water. This condition causes algal bloom and growth of aquatic plants. When the algae die, they sink to the bottom and the process of decomposition proceeds. This process uses up oxygen and as a result, aquatic animals die due to lack of oxygen.

Air Pollution

Do you know that cars are one of the major contributors to air pollution? Pollutants can enter the air as gases, liquids, or solids. Cars burn fuel and produce harmful gases-carbon dioxide, nitrogen oxides, and hydrocarbons. Figure 12 shows the harmful pollutants present in the air.

In Metro Manila where a great volume of cars travel each day, smog blankets the area, nitrogen oxides, and hydrocarbons from car exhausts react with water vapour or dust particles and produce new irritating chemicals.

Carbon dioxide acts like a blanket over the Earth, holding in the heat that would otherwise radiate back into space. The trapping of heat by gases in the earth's atmosphere is called the greenhouse effect. The greenhouse effect is a natural process. As carbon dioxide in the atmosphere increases, greenhouse effect also intensifies-this will lead to global warming. Global warming is an increase in the earth's temperature from the rapid buildup of carbon dioxide and other gases. This, in turn, could change the world climate patterns.

Are there factories in your area? Factories and power plants that burn coal are also major contributors to air pollution. Coal contains sulfur. When coal burns, sulfur combines with oxygen in the air to form sulfur dioxide, with choking odor. Power plants also burn coal to give off particulates into the air. Particulates are tiny particles of soot, dust, and smoke. These particulates block sunlight and get into your lungs when you breathe. Do you see smog and smell such foul odor and often wonder where it comes from? Well, your place might be a victim of air pollution from the factories nearby.