Deforestation is the permanent destruction of indigenous forests and woodlands. The term does not include the removal of industrial forests such as plantations of gums or pines. Deforestation has resulted in the reduction of indigenous forests to four-fifths of their pre-agricultural area. Indigenous forests now cover 21% of the earth's land surface.
The rate at which deforestation is occurring is a great concern to all. Currently, 12 million hectares of forests are cleared annually. Almost all of this deforestation occurs in the moist forests and open woodlands of the tropics. At this rate all moist tropical forest could be lost by the year 2050, except for isolated areas in Amazonia , the Zaire basin, as well as a few protected areas within reserves and parks. Some countries such as Ivory Coast , Nigeria , Costa Rica , and Sri Lanka are likely to lose all their tropical forests by the year 2010 if no conservation steps are taken.
The causes of deforestation are as follow: The conversion of forests and woodlands to agricultural land to feed the increasing population. The development of cash crops and cattle ranching, both of which earn money for tropical countries; the commercial logging (which supplies the world market with woods such as meranti, teak, mahogany and ebony) destroys trees and the felling of trees for firewood and building material; and heavy browsing of saplings by domestic animals like goats.
The carbon cycle. Forests act as a major carbon store because carbon dioxide (CO2) is taken up from the atmosphere and used to produce the carbohydrates, fats, and proteins that make up the tree. When forests are cleared, and the trees are either burnt or rot, this carbon is released as carbon dioxide (CO2222
The water cycle. Trees draw groundwater up through their roots and release it into the atmosphere during transpiration. In Amazonia , over half of all the water circulating through the region’s ecosystem remains within the plants. With removal of part of the forest, the region cannot hold as much water. The further effect of this could be a drier climate.
DID YOU KNOW?
* An area of forest equal to 20 football or rugby fields is lost every minute.
There has been a great concern on earth’s ailing condition especially when effects of man’s inadvertent progression in the world of science and technology created a network of environmental problems. Thus the word ‘pollution’ comes to mind. We think that it is very important for people to realize that different types of pollution such as water, air and land are not inconsequential of one other. In fact, each of the parts of an environment – air, water and land – depends upon the others and the flora and fauna within the environment. The relationships among all living and non-living things in an environment make up an ecological system, known as the ecosystem. All the ecosystems of the earth are interdependent.
Pollution comes in many forms; agricultural, urban runoff, industrial, sedimentary, animal wastes, and leeching from landfills/septic systems just to name a few. These pollutants are very detrimental to the environment. Whether they are alone or combined with another form of pollution they are very harmful. Over the last hundred years the problems with pollution have been increasing with time. This is due to both the increase in human population, and the increases in technology we have made as a society. If we plan on having our resources here for many years to come we are going to have to make some drastic changes in the way we treat the earth, and these changes will have to start with our pollutants.
Air pollution is nothing new. Ever since the discovery of fire, less-than-desirable substances have been vented into the air. Pollution is the pressure within the air of one or more substances that are harmful to human health, welfare, animal or plant life, or property. In the past with air pollution we included mainly the outdoor pollutants, although in recent years this is not the case. Today we separate pollutants in to two categories. Primary pollutants, which means that they come directly from various sources, and secondary pollutants, which are the by-products of chemical interactions of the primary pollutants within the atmosphere.
Consequently there has been an increase in the death rates resulting from various diseases caused by air pollution varying from breathing problem to lung cancer. Air pollution does not only affect people but it also damages the whole ecological system in which plants and animals are harmed as well. Air pollution has reached such a critical stage where it affects the earth's atmosphere as it lets in more harmful radiation from the sun. Our polluted atmosphere is becoming a better insulator, thus, preventing heat from escaping back into space. That is why there is a global rise in temperature, which scientists refer to as " global warming". As a result of this rise in temperature the world food supply and sea level will be affected.
Water pollution is one of the world's worst forms of pollution and has been an increasing problem over the last few years. Agricultural pollution is a very big contributor to water pollution. Problems we see with agriculture are applications of fertilizers, insecticides, and pesticides. We have made vast improvements in the types of chemicals we are using, as to how environmentally friendly they are. Yet even today the effects of these chemicals are that when it rains, soil erosion may occur and the surface runoff to the oceans and seas will become polluted from the use of these chemicals. The excessive amount of nutrients from the fertilizers that are washed into lakes and rivers leads to eutrophication. The nutrients encourage the rapid growth of algae and other water plants until they cover the entire water surface. The plants prevent sunlight from entering the water, hence killing other plants in the water below. When the plants decay, the oxygen content is reduced, and this affects the fish and other organisms that live in the water. The water then becomes filled with rotting fish and plants, and is too foul for human use.
Take a look at a glass of water, it may appear clear, but there are really millions of microscopic pollutants floating in it. Approximately 70% of the earth's surface is covered by water; water is a very dynamic system, any change in its normal content could affect local, regional, and eventually worldwide water. Oil is one of the world's biggest pollutants; oil is usually spilled or leaked from land or rivers and flows from them to the sea or ocean. The more direct form of oil polluting the water is when ships transporting oil leaks or the ship crashes. Oil can also ruin shores it can was up on them and become tar like lumps; some coat fur of animals and can effect their heating system. The oil can seep into streams and lakes and groundwater and contaminate them. Also some oil can find its way into other sources causing hazardous water to be consumed.
Air can be polluted by the introduction of dust and smoke particles, as well as the release of harmful gases into the air. The harmful gases include sulphur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides. These pollutants cause severe problems such as smog, haze, acid rain, global warming and the depletion of the ozone layer. Air pollution can be due to natural or human causes. Erupting volcanoes as well as forest fires caused by hot and dry weather send large amounts of dust and smoke into the air. Human activities have also contribruted to air pollution. Industries emit large amounts of toxic gases into the air. The vehicles we drive release harmful gases such as nitrogen oxides and carbon monoxide that can cause cancer.
Society as a whole faces many environmental problems, and as a result, environmental awareness tends to be a pressing issue. Everyday, people should recycle cans, glass bottles, and newspapers. Many people can buy bottled water, or own filters for their tap water, as a health precaution from the pollutants in normal everyday drinking water. Everyone should be concerned with issues such as, littering, and what is going to happen when there are no more land fills. There are some people who talk about the introduction of the electric car sometime in the near future. Air pollution is perhaps the biggest environmental issue the Earth is facing. Automobiles are responsible for a notable amount of the air pollution problem. Of course, on the other hand so are factories. If the fight against air pollution were to be taken to a higher level, putting pressure on factories that produce air pollution will have a greater effect than focusing on automobiles. The solution for problems caused by automobiles can only be taken to the level of removing vehicles off the road that cause excessive pollution. What do you think? How would you put a stop to the pollutions that are going on around you?
Desertification refers to the formation of deserts when land loses its productivity and becomes bare. In the last three decades, researchers have noticed that the total area covered by deserts has been increasing by as much as 200 000 square kilometres each year. It has been estimated that a third of Asia and a fifth of Africa, including land that is currently being farmed, are in danger of becoming deserts.
It was previously thought that desertification occurs along the edge of deserts, expanding the desert area. However, recent studies have shown that desertification can occur in semi-arid areas anywhere in the world, including places far from existing deserts. Semi-arid areas receive an annual rainfall of 250 to 500 millimetres. This amount of rain is sufficient to support vegetation such as grasses, scrubs and small trees
Not all deserts have to be hot, since some are located in very cold regions of the planet. Not all deserts are made of sand, either-some are rocky, and others can be formed by salt or ice. But, all deserts do have one thing in common: they are regions that almost continuously suffer from drought, so little moisture that clouds do not formed-that is why the desert sky is almost clear and bright, which means that the ground is always exposed to the direct action of the Sun's rays.
The air's temperature can reach 100 to 120 degrees Fahrenheit, and the surface temperature between day and night cause the rocks to break until they form fragments that are so small that the wind carries them away.
By the process of desertification, the Sahara desert is growing at a rate of 0.6 km a year. 'Millions of people in this area are suffering from the effects of this phenomenon, which causes the earth's ecosystems to deteriorate" . Sand dunes have covered large expanses of agricultural farmlands, oasis and ponds, causing farmers to abandon the season and their homes. Desertification is posing a serious threat to Nigeria's economy as jobs are lost, and food is becoming scarce. The deteriorating economy is at the fault of the Nigerians, the negative effects of desertification could have been, and still can be slowed down and even prevented by the Nigerian government and its people. Although desertification is a natural process of an ecosystem, it could have been stopped. The people of Nigeria and even many surrounding countries have taken up many processes that are increasing the rate of desertification. Nigerians are poor and live by the easiest ways of life, which is very destructive towards the environment. Instead of looking for long-term processes to help take them out of their poverty, Nigerians over cultivate and overgraze the land they live on.