Deforestation and the Greenhouse Effect
Created | Updated Mar 4, 2005
Every minute, areas of rainforest the size of about 37 football pitches is cut down all over the world. Why are these trees being cut down? What do we use them for?
The main problem areas where deforestation is now taking place are the tropical rainforests, situated on and around the equator. Other areas of forest in developed countries are now generally managed forests, because many of them were cleared during the bronze age, but the developing countries where rainforests are situated are destroying their forests at an alarming rate.
What are the Causes?
The main causes of deforestation are to use the trees for fuel, making wood and paper products, cattle ranching, farming, mining, road building etc, and rapid population increase in developing countries and to use the land for cattle ranching.
Fuel:
Half of all the trees cut down in the world are used for fuel. This is needs a lot of land because you need to grow crops in different areas.common in developing countries where there are often no readily available alternatives. This in its self is not a huge problem; only most of these trees are not replaced, which is a problem.
Wood and Paper Products:
The use of wood and paper mainly in developed countries is another huge factor driving deforestation all over the world. Hardwoods like mahogany are sought after for furniture, and they are very valuable. In every square kilometre of rainforest, there is probably only half a dozen mahogany trees, yet the whole area is often cut down, for those few trees, and the other trees are just left to rot, even if they are useful for something.
Cattle Ranching:
In developing countries, which is where the majority of rainforests are, this is a major cause of deforestation. Areas of rainforest are cleared by cutting down all the vegetation, and then burning it. They can then grow pastures of grass, which they put cattle on to graze. As soon as the cattle are a certain age, they are slaughtered. Although some of the meat goes to the locals, alot of the meat goes to the cheap meats industries in countries such as the UK and USA,for example fast food and corned beef. Huge areas of rainforest have to be cleared to support a few hundred cattle. After a few years, all the nutrients have been removed from the already poor soil and the land is useless, so another area of rainforest has to be cleared.
Farming:
Large areas of rainforest are cleared for farmland all over the world. In developing countries there are two main types of farming: “Slash and Burn” and “Subsistence Farming”.
Slash and Burn: is when areas of forest are cleared to grow crops for a couple of years, then left for a few years for the rainforest to recover, then the process starts again. Slash and burn is the most sustainable of the farming methods, but only if the population in the area is low, because as soon as you get more people in an area, there is less land available for each person, and areas of land don’t have enough time to recover, so the soil is quickly exhausted. Slash and burn also increases air pollution.
Subsistence Farming: is when people farm small areas of land that has been cleared to feed them selves and provide a small surplus to buy other goods. The problem with this method is that the soil is quickly exhausted of its few nutrients and no more go back into the soil so the land quickly becomes useless, so they then either have to rely on fertilizers or clear another patch of land.
Mining and Infrastructure:
Rare minerals like gold, bauxite (aluminium ore), and iron ore are discovered in areas of rainforest. To mine them, huge areas of rainforest are cleared, not just the area where the mine is, but roads and other methods of transportation to transport the minerals. Also, Hydroelectric dams are built, to provide electricity, and so massive areas of land are flooded to create artificial lakes, which also causes huge environmental damage. For example gold mining in the Amazon Basin and tin mining in Indonesia.
Population Increase:
The world population of humans is increasing. With this increase, we are running out of space, so more and more, we destroy natural habitats to build settlements, something which is called urbanisation. Also, in developing countries, people are moving into previously undisturbed areas of rainforest, to log, mine or farm. For example on the Indonesian island of Java, the population has grown so rapidly that people are incouraged to move to other less densly populated islands, where they cut down the rainforest for farming and homes.
What are the Effects of this Deforestation?
Local effects of deforestation include the washing away of the soil in the frequent rains that hit tropical regions because the trees can no longer hold the soil in place if they are cut down, this causes mudslides. The soil is leached of nutrients by the water, and there are no nutrients from decomposition of vegetation and animals to replace them, so the soil quickly becomes infertile.
Also rivers silt up as soil is carried away, which impacts upon the wildlife that lives in the rivers as they depend upon the clearness of the water, for example fish.
If large areas of rainforest are cleared, the rainfall pattern can also change, because there is less evapotranspiration from trees, because there are less of them, so there is less moisture in the air, so less rainfall occurs.
Another more worrying effect of deforestation is Global Warming. The earth is made habitable by a process called the Greenhouse effect. Gases, incidentally called “Greenhouse Gases”, mainly carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and water vapour, are found it the atmosphere. When light rays from the sun come into the earth’s atmosphere, they are absorbed by the earth, and then emitted as heat rays; the greenhouse gases trap some of them in the atmosphere, warming the earth. The Greenhouse Effect is essential for life to be able to live on earth because without it, it would be too cold.
Current scientific theory suggests that When the level of greenhouse gases in the atmosphere increases, more of the heat rays are trapped in the atmosphere, gradually, warming up the earth. This warming up of the Earth might seem quite nice, after all, we might get some good weather in the UK for a change, but it isn’t good. Already, from the effects of global warming, the polar ice caps are melting, and if this continues we are set for a significant rise in sea level, flooding many places, also, places which are now full of life could become deserts if rainfall patterns change with this heating.
Deforestation comes into the rise of Greenhouse Gases because trees have a large store of carbon in them, they take in CO2 from the atmosphere in Photosynthesis and although a lot of it that they take in comes out through Respiration, some of it is stays in the tree in the form of Carbon. When you cut down, or especially burn trees, this carbon reacts with Oxygen in the atmosphere and becomes CO2.
So, Less Trees Mean More Carbon Dioxide in the Atmosphere and an Increased Greenhouse Effect, Which in Turn Means More Global Warming.
Carbon dioxide levels in the atmosphere are also rising because of the increasing burning of fossil fuels (coal, oil and natural gas). Fossil fuels are made from dead organisms, which have gradually been compressed over millions of years, so they contain a lot of carbon, so when you burn them; you release carbon dioxide into the atmosphere. This increased use of fossil fuels, contributing to Global Warming lead 160 nations to come together in Kyoto, Japan, to try to reduce emissions in 1997. In 2001, the newly elected president of the USA, George W. Bush declared that the USA would not sign the Kyoto Protocol because it would be economically damaging for the USA. Without the US’s backing, the Kyoto Protocol is not going to have anywhere near as much effect on global warming, because the USA has the highest emissions of anywhere in the world. As much as all the other countries try, the protocol needs its backing to have any real chance of reducing Global Warming, which if not reduced could have disastrous effects for all.
The Forestry Commission
The Forestry Commission is a governmental department that was set up to protect and increase the size of UK woodlands.
Sustainable forestry is when you manage forest and put as much back into the forest as you took out. So for every tree you cut down, you plant two more seeds and so on. Sustainable forestry is a good idea because even though you are cutting down trees, if you replace them then the amount of CO2 that can be absorbed and stored in the trees can stay about the same, therefore not increasing the Greenhouse Effect.
Land is set aside for trees with agreement from the owner and the local community that the area of land should be a woodland area. Grants are given to help with costs of planting etc. Pine trees are often planted as opposed to Oak and other deciduous because they are fast growing and there is a high demand for pine furniture and products.
To help this issue, you could:
- -Turn off light bulbs
- -Turn off the light when you are not in a room, and use more energy efficient bulbs, not only will this save you money, but it reduces the amount of electricity that needs to be generated and so less fossil fuels have to be burned.
- -Use public transport, or walk, or cycle if possible, only travel in a car when necessary, and if you know people who are going to the same place, try to car share, so less petrol is used, reducing CO2 emissions.
- -Try to buy paper or wood products that are certified by the Forestry Commission as being from sustainable, managed woodlands.
- -Avoid excess printing of documents off the computer, and any copies that are just drafts of documents that you do not wish to keep, turn over the paper and print on the other side, other draft documents, saving paper and money.
- -Recycle as much as possible, so less trees have to be cut down.
- -Encourage people you know to do any or all of the things above.
Even if you only turn off the light when you leave a room, the amount of energy that you save builds up over a period of time, and if bit by bit, more and more people start to do that, think of how much energy will be saved, therefore reducing the amount of fossil fuels that need to be burned, and that reduces the amount of CO2 that enters the atmosphere, reducing Global Warming.
If you print on both sides of the paper, think how much paper you will save over time, quite a lot, and if all the people on your street do that, how many trees would you save?
Small actions do matter, even if they don’t seem to. Most of the time, they involve little effort from you and a lot of them save you money in the long run, and while doing them, you are helping to save the world from ecological disaster. Which, some people would argue it is already too late to do so, but if it is not attempted than it certainly wont be.
Related Websites
http://www.forestry.gov.uk/
http://earthobservatory.nasa.gov/Library/Deforestation/
http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.htmhttp://www.forestry.gov.uk/
http://www.oxfam.org.uk/coolplanet/ontheline/explore/nature/rainforest/deforest.htm
http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.htmlhttp://www.oxfam.org.uk/coolplanet/ontheline/explore/nature/rainforest/deforest.htm
