U10: Impact on the Environment

Key Learning Points:

• Man's actions on the environment (the impacts) can be good (positive) or bad (negative).


• On the positive impacts, man has created man-made materials such as alloys, plastics and ceramics.


• This gives us a wider variety of choices of materials and also allows us to make things with better properties.


• In addition, this extra choices of materials will not exhaust (use up) our natural materials too quickly.


• On the negative impacts, man has removed trees (deforestation) because we need more land spaces and timber.


• Thus, deforestation can cause the loss of living things (loss of food, shelter and therefore lives), soil erosion (no roots to hold the top layer of fertile soil during floods) and global warming (extra carbon dioxide in the air causing trapping heat in the Earth, thereby causing a rise in the Earth's temperature).


• Besides deforestation, man has contributed to pollution of the land, air and water.


• The common pollutants include litter and rubbish, human waste, harmful chemicals, smoke and haze, as well as CFCs.