Model Example of a Cause and Effect Essay
Many of the world’s rainforests are being destroyed. Discuss the causes of this destruction by focusing on logging, mining and agriculture, and its effects on the environment and humans.
One ecosystem that is facing major environmental problems is the tropical rainforest. Tropical rainforests are found in South America, Central Africa and South East Asia. These are areas of constant high temperatures and rainfall, and are home to the majority of plant and animal species found on Earth. Rainforests are very important. However, they are slowly being destroyed by deforestation at a rate of 78 million acres a year (Internet Geography, 2007). It is the massive scale of this process that concerns environmentalists and scientists. They claim that clearing large areas of rainforest could lead to disastrous long-term effects. Therefore, the purpose of this essay is to discuss the causes of deforestation and its effects on humans and the environment.
The main causes of deforestation are commercial logging, mining and large-scale agriculture. The International Tropical Timber Organization claims that commercial logging is the largest single cause of forest destruction (Lange, 2011) and research shows that five million hectares are destroyed every year to provide wood for the construction industry (Save the Rainforest, 2005). In addition to this, mining in the rainforests also leads to deforestation. Land for mining is cleared of all vegetation, causing soil erosion (Internet Geography, 2007). Agricultural land use is another major cause of deforestation. For example, enormous areas of forest are cleared for cattle grazing. This grazing is usually to meet demand for beef in other parts of the world (Lange, 2011).
As a result of deforestation, there are several effects on the environment. The first of these is the loss of biodiversity. Although rainforests account for only a small proportion of the land surface of the planet they provide the habitat for 50 to 70% of all species on Earth (Internet Geography, 2007). However, Collins (1991) states that every day 40 species become extinct and as a result, biodiversity is being reduced. Deforestation also leads to climate change. As forests are destroyed, the air above them becomes hotter and drier. Collins (1991) claims this affects the circulation of water and therefore may affect climate in other regions. Furthermore, the amount of CO2 absorbed after deforestation is reduced, which increases the greenhouse effect and makes global warming worse. According to Collins (1991), annual burning of the Amazon rainforest produces 500 million tons of CO2, which is released into the atmosphere.
As well as these effects on the environment, deforestation can affect humans. Firstly, there is the possible loss of valuable medicines. Collins (1991) states that 25% of modern pharmaceuticals originate from tropical rainforests. Further destruction of this valuable resource could mean the extinction of plant species that could contain cures for diseases such as cancer and AIDS (Save the Rainforest, 2005). Deforestation also leads to the loss of land for indigenous people. It is estimated that 50 million people worldwide l