Environment

"The earth is unique because it has conditions favourable for all forms of life on it. Our environment includes physical elements land, water and air and the biological elements of plants, animals and micro-organisms."

In previous class, we saw environment is our basic life support system. It provides the air we breath, the water we drink, the food we eat and the land where we live. How do human beings modify this natural environment? The car fumes pollute the air, water is collected in a pot, food is served in vessels and land is used to build factories. Human beings make cars, mills, factories and manufacture containers. This is how human beings modify natural environment.

1.0Introduction

• After the long vacation, when Ravi started going to school again, he noticed that the only playground next to his school was dug up.
• People said that a huge building with many flats will be constructed there.
• Ravi was almost in tears, when he realised that the big playground with its soft grass, marigolds and butterflies is gone for ever.
• He shared his feelings with his classmates.
• In the assembly, the Principal too sadly observed, "See how our environment is changing."
• In the class Ravi asked his teacher, "What is environment?" "Whatever you see in your surroundings," said the teacher.
• Ravi thought aloud, "That means, the school building, tables, chairs in the classroom, even that open field, the road, the garbage, my friends - all are parts of our environment"!
• "Yes" said the teacher, "but wait..... Some objects are created by nature - for example, mountains, rivers, trees, animals. Others are made by people - for example roads, cars, clothes, books".
• "Why is our environment changing?" "It's all because of our needs. They are increasing day by day; we are therefore modifying and at times even destroying our natural surroundings".
• Biotic The world of living organisms. e.g. plants and animals.
• Abiotic The world of non-living elements. e.g. land.

• The place, people, things and nature that surround any living organism is called environment.
• It is a combination of natural and human made phenomena.
• While the natural environment refers to both biotic and abiotic conditions existing on the earth, human environment reveals the activities, creations and interactions among human beings.

2.0Natural Environment

• Land, water, air, plants and animals comprise the natural environment.
• Lithosphere is the solid crust or the hard top layer of the earth. It is made up of rocks and minerals and covered by a thin layer of soil. We can also say lithosphere is the land on earth.
• It is an irregular surface with various landforms such as mountains, plateaus, plains, valleys, etc.
• Landforms are found over the continents and also on the ocean floors.
• Lithosphere is the domain that provides us forests, grasslands for grazing, land for agriculture and human settlements. It is also a source of mineral wealth.
  
  Domains of the Environment
• The domain of water is referred to as hydrosphere.
• It comprises various sources of water and different types of water bodies like rivers, lakes, seas, oceans, etc.
• It is essential for all living organisms.
• The atmosphere is the thin layer of air that surrounds the earth.
• The gravitational force of the earth holds the atmosphere around it.
• It protects us from the harmful rays and scorching heat of the sun.
• It consists of a number of gases, dust and water vapour.
• The changes in the atmosphere produce changes in the weather and climate.
• Plant and animal kingdom together make biosphere or the living world. It is a narrow zone of the earth where land, water and air interact with each other to support life.

3.0Ecosystem

It is a system formed by the interaction of all living organisms with each other and with the physical and chemical factors of the environment in which they live, all linked by transfer of energy and material.

What is ecosystem?

• All plants, animals and human beings depend on their immediate surroundings.
• Often they are also interdependent on each other.
• This relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem.
• There could be an ecosystem of large rain forest, grassland, desert, mountains, lake, river, ocean and even a small pond.
  
  The Ecosystem

4.0Human Environment

• Human beings interact with the environment and modify it according to their need.
• Early humans adapted themselves to the natural surroundings.
• They led a simple life and fulfilled their requirements from the nature around them.
• With time needs grew and became more varied.
• Humans learn new ways to use and change environment.
• They learn to grow crops, domesticate animals and lead a settled life.
• The wheel was invented, surplus food was produced, barter system emerged, trade started and commerce developed. Industrial revolution enabled large scale production.
• Transportation became faster.
• Information revolution made communication easier and speedy across the world.
• A perfect balance is necessary between the natural and human environment.
• Humans must learn to live and use their environment in a harmonious way.

Social, political, cultural, economical, etc. systems created by humans is also part of human environment.

5.0Mind Map