UNIT ONE AN INTRODUCTION TO EVS Meaning: The term environment is derived from the French word ‘environ’ meaning surrounding. As such, anything surrounding us is called environment. It literally means the surroundings in which we are living. It includes all those things on which we are directly or indirectly dependent for our survival, whether it is living component like animals, plants or the physical component like soil, air and water. The environment creates favorable conditions for our existence and development. Definition: According to the Environment Protection Act 1986, “Environment is the sum total of water, air and land, their interrelationships among themselves and with the human beings, other living beings and property.” As such, environmental science is the study of the environment including its components. SCOPE OF EVS The scope of EVS can be studied under the following heads: • Developing an awareness and sensitivity to the total environment and its related problems. • Motivating people for active participation in environmental protection and improvement • Developing skills for active identification and development of solutions to environmental problems • Imbibe and inculcate the necessity for conservation of natural resources • Evaluation of environmental programs in terms of social, economic and aesthetic factors.
IMPORTANCE OF EVS • We will begin to appreciate and adopt the idea of sustainable development without destruction of environment • To increase knowledge about various types of environments and different environmental hazards • Playing an effective role in protecting the environment by demanding changes in law • Having a positive impact on quality of life • Creating a concern and respect for the environment NEED FOR PUBLIC AWARENESS Increasing population, urbanization have generated a huge pressure on natural resources and led to a degradation of our environment. To prevent the environment from further degradation, public participation is a must. We can increase awareness regarding various environmental issues through a process of environmental education. It will help us in making sensitive towards environmental problems and generate possible solutions. In order to increase public awareness, Government has been trying to create awareness through various campaigns and drives such as Save Tiger campaign, Go Green initiative, Clean India drive, Namami Gange Project, etc. UNIT TWO NATURAL RESOURCES Our environment provides us with a variety of goods and services necessary for our existence and survival. These resources or services provided by nature are known as natural resources. Thus, water, air, soil, minerals, coal, forests, crops and wildlife are all examples of natural resources. Broadly, natural resources can be studied under the following heads:
• Forest Re3sources • Water Resources • Mineral Resources • Energy Resources • Land Resources • Food Resources FOREST RESOURCES Forests are one of the most important natural resources on this Earth. About 1/3 rd of the World’s land area is forested. But it is a matter of concern that almost everywhere the cover of natural forests has declined over the years. The greatest losses have occurred in Asia where 1/3 rd of the forest resources have been destroyed. USES OF FORESTS Forests are of immense value to us. Importance of forests can be studied under the following heads: Fuel wood: For the rural population, wood is an important source of energy for cooking. As such, forests are a major source of fuel wood for rural population. Fodder: Fodder from the forest forms an important source of food for cattle and other grazing animals. There are many varieties of grasses, shrubs that are used as fodder Fruits: Fruit trees are an important source of food for human beings Medicinal Use: Since time immemorial, humans have been depending on the forests to cure them of various ailments. Leaves and other parts of various trees having medicinal properties are used to make useful Ayurvedic medicines. Maintenance of Oxygen Levels: During photosynthesis, plants take in carbon dioxide and release out oxygen as a by- product which is so very necessary for survival of living beings. As such, plants help to maintain oxygen levels in the atmosphere Prevention of Global Warming: Carbon dioxide is considered to be a green house gas. Its increased levels in the atmosphere results in green house effect thereby causing global warming. Trees in the forests absorb carbon dioxide during the process of
photosynthesis thereby regulating its levels in the atmosphere. This results in reduction in global warming Prevention of Dust Storms and Soil Erosion: Trees in the forests hold the soil particles firmly with their roots. As such, trees prevent the soil from getting eroded. Not only this, trees also act as wind breakers and regulate strong winds and reduce the intensity of dust storms. Preservation of Water Cycle: Forests maintain water cycle on Earth. Plants and trees in forests absorb water needed for their nutrition. The excess water is released in the atmosphere in the form of water vapours. The water vapours condense and form clouds which cause rainfall Forests provide us products: Trees provide us with a variety of products such as wood which is used in making furniture, pulp which is used to make paper, various food items, oil, rubber, etc Natural Homes: Forests are homes for millions of wild animals and birds DEFORESTATION Deforestation can be understood as the clearing of forest cover or tree plantations in order to accommodate agricultural, industrial or urban use. It is simply the felling or cutting down of trees on a large scale. It has been a regular practice all over the world. Over the last century, the forest cover along the globe has been greatly reduced. According to United Nations Food and Agriculture Organization, an estimated 18 million acres of forests are lost each other. MAJOR CAUSES OF DEFORESTATION • Agricultural Activities: Agricultural activities are one of the reasons behind the deforestation. In order top meet the growing food requirements of people, trees are cut down in order to pave way for agricultural land. • Logging: Wood based industries like paper; matchstick, furniture, etc also need huge amounts of wood supply. Also wood is used as fuel wood in the rural areas. Therefore, trees are cut down extensively • Urbanization: Another reason behind deforestation lies in urbanization. Massive destruction of forests occur to execute various development projects such as road construction, highways, big dams, housing projects, etc