Assess the view that human activities have a greater impact on the physical environments in LEDCs than in MEDCs
A LEDC is a less economically developed country, for example, a country in the developing world and a MEDC is a more economically developed country, for example, a country in the industrialized or developed world.
The human population is growing all the time and its impact on the physical environment is increasing.
All our activities have an impact on;
- Deforestation, cutting down trees in order to use the land or the wood which is a big problem in the Amazon Forest in South America, draining marshes, mining damming and redirecting rivers and flooding land cause Drastic changes to the ecosystem.
- The growth of cities. So more land is needed for building, and generating more pollution, e.g. from congestion.
- Industry needs more and more raw materials. Processing and transporting raw materials and finished goods generate pollution.
- Intensive farming methods require the use of chemicals such as inorganic fertilisers and pesticides. Genetic engineering will have an impact that we do not yet understand.
Deforestation in the Amazon forest leads to;
- The loss of animals, insects, birds, etc. that live in the forests.
- Soil erosion. The tree roots hold the soil together. The soil will also quickly lose its fertility once the trees are removed.
- Reduction in oxygen levels. Over one third of the world’s oxygen supply comes from the trees of the rain forest.
- The nutrient cycle is broken because there are no rotting leaves to fall from the trees.
- Changes in climate. Without trees there will be a decrease in evapotranspiration and therefore of water vapour in the air. This will reduce rainfall and may mean that the Amazon basin turns into desert.
- Greenhouse effect. As the trees are burnt, this releases carbon, thus contributing to the greenhouse effect and global warming.
Trees take in carbon dioxide when they photosynthesise. Deforestation is cutting down trees and so this will increase the amount of carbon dioxide in the atmosphere. The wood may also be burned, which will add further to the carbon dioxide levels.
The Greenhouse effect is when the layer of carbon dioxide acts like a greenhouse keeping the reflected rays of the Sun in. This is causing the Earth to slowly warm up. aIt can cause the polar ice caps to melt and then sea levels will rise. Large areas of lowland Britain will be under water, including London. Our climate will also change.
The effects of Deforestation
There are local and global effects of deforestation in the Amazon. On a local scale, the indigenous tribes that have lived in the rainforest for many years are seeing their traditional way of life, their environment destroyed, and the culture is felt to have been sabotaged due to Western cultural influences brought over by the MEDCs countries. They are also felt to have been exploited by big co-corporations companies who have taken their land and cared little about the needs of the Amerindian tribes who live in the Amazon.