Chapter 1 — Environment

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

Land, water, air, plants and animals comprise the natural environment. These are organised into four domains: lithosphere, hydrosphere, atmosphere and biosphere.

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, with an irregular surface featuring landforms such as mountains, plateaus, plains and valleys. It provides forests, grasslands for grazing, land for agriculture and human settlements, and is a source of mineral wealth.

Hydrosphere is the domain of water. It comprises various sources of water and different types of water bodies like rivers, lakes, seas and oceans. It is essential for all living organisms.

The atmosphere is the thin layer of air that surrounds the earth, held in place by Earth's gravitational force. It protects us from the sun's harmful rays and scorching heat. It consists of gases, dust and water vapour, and changes in the atmosphere produce changes in weather and climate.

Biosphere is the plant and animal kingdom together — the living world. It is a narrow zone of the earth where land, water and air interact with each other to support life.

An ecosystem 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. Examples include large rain forests, grasslands, deserts, mountains, lakes, rivers, oceans and even a small pond.

Biotic refers to the world of living organisms, for example plants and animals. Abiotic refers to the world of non-living elements, for example land.

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, such as roads, buildings and factories.

Early humans adapted themselves to natural surroundings and fulfilled their requirements from nature. Over time, needs grew and humans learned to grow crops, domesticate animals and lead a settled life. The wheel was invented, surplus food was produced, the barter system emerged and trade started. The industrial revolution enabled large-scale production, transportation became faster, and the information revolution made communication easier and speedy across the world.

The barter system is a trade in which goods are exchanged without the use of money.

World Environment Day is celebrated on 5 June every year.

The word 'environment' comes from the French word 'Environer' or 'Environner' which means 'neighbourhood'.

Yes — the NCERT PDF for Class 7 Social Science Our Environment Chapter 1 Environment is available free with no sign-up required on cbseprepmaster.com.