The major forms in which environment has been degraded due to human activities are deforestation, desertification, emission (pollution), erosions and extinction.
Destroying or damaging the forests in the ecosystem is known as deforestation. With increasing population there was an urgent need for land for agricultural and production purpose. The forest cover in India has been lost up to 367 sq.km. in two year between 2007-2009. Forest is a natural habitat and source of livelihood for thousand of animal and human species. When forest is cut, these species tend to get endangered, soil gets eroded and the atmosphere and rainfall pattern gets affected adversely.
Desertification is the expansion of desert land in the non desert areas. Deforestation and over grazing results drought and floods, when soil loses its water holding capacity resulting in expansion of deserts. Similarly excessive use of chemical fertilizers in the fertile lands, also make the soil arid and transforms the previously fertile land into deserts.
3. Emission and Pollution
Emission is the process of releasing chemicals or hazardous substances including poisonous gases. Emission causes different types of pollution like air pollution, water pollution, soil pollution etc. Excessive emission of carbon dioxide, carbon monoxide and other gases can result in global warming, which is a major threat to earth’s environment
Erosion is the phenomena where the upper most layer or the surface of the land is worn out or lost. As mentioned earlier cutting down of the trees prevents holding of the flowing water resulting in land surface in the area getting washed away. This form of degradation can cause a severe threat to the food production leading to food shortage and famine.
There is a natural process of species evolution and decay but with human intervention the process of species getting extinct has intensified. Species getting extinct or even endangered (existing in small numbers) can affect the food chain and food web adversely and disturbing the balance in the ecosystem. For e.g. if the frogs decrease in number mosquito population will multiply leading to diseases like malaria or yellow fever.