Chapter 1 - Environment

• World Environment Day is celebrated on 5^th June every year.
• French word Environer or Environner means ‘neighbourhood’.

1. The nature, place, people and things that surround the living beings is called environment.
2. Environment is a combination natural (like mountains and rivers), human and human-made things (like roads and cars).
3. Environment is our basic life support system. It provides the air we breathe, the water we drink, the food we eat and the land where we live.
4. Natural environment relates to biotic and abiotic-conditions, while the human environment refers to the activities, creations and interactions among human.

Natural Environment

1. Everything around us that is natural and not made by humans is part of the Natural Environment.
2. Land, water, air, plants and animals comprise the natural environment.

Lithosphere (lithos means rocky)

1. is the solid, outer part of the earth, consisting of the crust and upper mantle
2. is made up of rocks and minerals and covered by a thin layer of soil
3. is an irregular surface containing landforms like mountains, plateaus, plains and valleys
4. provides forests, grasslands, land for agriculture and human settlements
5. is a source of minerals

Hydrosphere (hydra means water)

1. is the part of the Earth that contains the water
2. includes water bodies like streams, lakes, oceans, seas, and rivers etc.
3. is essential for all living organisms

Atmosphere (atmos means vapour)

1. is the thin layer of air that surrounds the earth
2. contains a number of gases, dust and water vapour
3. shields us from the harmful rays and fiery heat of the sun
4. There is a change in the weather and climate if there is change in the atmosphere

Bioshphere (bio means life)

1. is the living component of the environment
2. is formed with the union of the lithosphere, hydrosphere, and atmosphere
3. includes all micro-organisms, plants, and humans, birds and all the other animals

The Eco-System

1. All living things depend on their surroundings and also on each other
2. An eco-system is the network of relationships between the biotic (living things like plants, animals and organisms) and abiotic (non-living things like weather, earth, sun, soil, climate, atmosphere) components in a given area. All the components in an eco-system are linked together through nutrient cycles and transfer of energy and material
3. Example of an Ocean Ecosystem: The whole ocean is one giant ecosystem and may have several different small ecosystems within it. Various organisms live in this ecosystem. Plants like seaweeds and algae, invertebrates like jellyfish and shrimps, fish such as sharks and mammals such as whales can be found in it. Many sea birds, who feed on the fish and other organisms that live in the ocean, also form a part of this system. If Humans fish in the sea for food, they also become part of this ecosystem.

Human Environment

1. Humans depend on environment for various resources like air, water, soil, plants, animals, minerals, metals and energy.
2. Humans change their environment to satisfy their ever-growing needs.

1. A perfect balance is necessary between the natural and human environment.
2. Environment is changing because of our increasing needs due to which we are modifying and sometimes even destroying our natural surroundings.
3. Humans must learn to live and use their environment in a harmonious way.