Some main reasons why areas of rainforests are cut down:
- Farming e.g. soya fields, cattle ranches
- Flooding areas of land as part of hydro electric power stations
- Logging to sell the timber
Once the trees go, the soil becomes infertile in one or two years, making it poor for farming.
Hunting becomes more difficult for the people who live there as the habitat for wildlife is lost. Traditional people's cultures are also lost.
The effects of deforestation:
Trees are removed.
Trees do not protect soil so nutrients are washed out by the rain.
Soil is now less fertile and the unprotected surface becomes dry and compacted.
It is hard for rain to soak into the soil, so flooding may occur.
New trees grow more slowly and there are less species.
Possible alternatives to deforestation:
You may think that the obvious solution to the problems of deforestation is simply to stop people cutting the trees down.
However, it's not always as straightforward as that. Most of the countries that have rainforests are trying to cope with poverty, debt and high rates of population growth.
Can they be blamed for trying to make some money?
Here are some alternatives to deforestation on a big scale:
- A mixture of different crops and trees are planted together. This variety helps prevent insect damage and soil erosion, as well as maintaining natural soil fertility.
- Banning sales of valuable hard wood e.g. mahogany.
- Less economically developed countries could have some of their debts reduced in return for setting up projects to protect their rainforests.
- Increased world trade in rainforest products at fair prices.
- National Rainforest Parks e.g. Korup in Cameroon. These act as wildlife reserves and may make some money through careful tourism.
- Portable sawmills to reduce damage caused by motor vehicles bringing logs to permanent sites.
- Reserves for people already living in the rainforests so that local land rights and lifestyles can be respected.
The global effects of deforestation:
The destruction of the rainforest is reducing the number of species of plants and animals as there are many species unique to different rainforests.
The destruction of the rainforest may lead to the loss of valuable plants that could be useful to people in the future e.g. medicines or crops.
The changes in humidity in deforested areas are creating less rainfall and having knock-on effects on savannah climates to the North and South. Rainfall is becoming more unpredictable.
The destruction of the rainforest is likely to increase the greenhouse gas carbon dioxide in the atmosphere. However this is a minor effect compared to burning fossil fuels for industry and transport.
Some scientists think the destruction of the rainforest is increasing global warming but others say climate change is natural. There have been cold and warm periods on Earth in the past.
Myths about deforestation:
The destruction of the rainforest is NOT increasing ozone in the atmosphere. This is due to chemicals (CFCs) released into the atmosphere by people.
The destruction of the rainforest is NOT making people short of breath as there is plenty of oxygen in the air to breathe.
It is estimated that 7.5 million hectares of rainforest are being cut down each year - that is the same as 20 football pitches every minute.
However, there is an area of rainforest the size of western Europe remaining in South America.