Maharashtra Board Class 4 EVS Chapter 24 Are we endangering our environment PDF Download

Are We Endangering Our Environment?

Twenty years ago, there were open fields around the city. Today there are new colonies there. There was a big spreading tree near the railway gate. Different kinds of birds and insects lived happily in the tree.

Where have those birds and insects gone today?

What similarities do you find between a city, a village and a forest?

What differences do you find between them?

Teacher's Note

In India, we see many cities growing very fast. Trees are being cut down to build houses and roads. This is harming birds and animals.

Exam Trick

Remember: When cities grow, trees go down. When trees go down, birds and insects have nowhere to live. This is bad for our environment.

Points to Remember

Cities change when new buildings come up.
Trees and animals need space to live.
Our choices affect nature around us.
We must think about the environment.

The Progress Made By Human Beings

Man is more intelligent than all other animals. He makes use of his intelligence to make his life more comfortable. All living things make use of what they find in their environment. But only man can carefully study the things in the environment. He produces new things from materials in the environment. Let us see how!

This is a story of about 150 years ago. Researchers found out how to use mineral oil. Man now had a new and useful fuel to use. He then invented some vehicles that would run on this new fuel. These include the motor-car, bus, truck and scooter. They also developed railway engines that would run on coal.

Previously, if one had to travel to another town, one had to walk or ride horseback or on a bullock cart. Various animals were used to carry burdens or to draw the carts. Now, we go by bus or railway trains. That helps to save both time and labour.

We take up various schemes to make our life easier and prosperous. We build dams to satisfy our need for water. We build roads and railways for transportation. Factories are set up to manufacture all the things we need. We build houses so that everyone can have a shelter of their own.

The things we need to do all this have to be obtained from the environment. We get them from places like forests, farms and mines. Water is used in the factories and then the waste water is let into rivers. All this has an effect on the environment. If the environment is harmed, it has harmful effects on all living things. And man is no exception.

Teacher's Note

Humans use many things from nature to live better lives. We use oil, coal, water, and trees. But we must be careful not to waste these things.

Exam Trick

Remember: Progress helps people, but it can hurt nature. Cars need petrol, houses need wood. We must use these things wisely.

Points to Remember

Man invented vehicles like cars and buses.
Factories make many things we need.
We take water and materials from nature.
Using nature too much can harm it.
We must think about the environment.

Growth Of The Population

A census was done in 1951. What was the population of our country then?

A census was done in 2011. What was the population of our country then?

In the last sixty years the population of our country has tripled. It is still growing. So, the demand for all those things that we need to take from the environment has increased many times over.

People could not get employment in villages. So they began to leave and to go to the cities in search of work. Cities became crowded. The population in the cities grew beyond limits. Cities began to experience a shortage of water. There were not enough houses for everybody. So people could not find a place to stay. There used to be open spaces and fields around the cities. New colonies came up there. And to build these new houses and colonies, the trees there had to be cut down.

In cities, one has to travel long distances to get to work. So people in cities began to buy vehicles that run on fuels. In all big cities, these vehicles spew smoke as they are driven around. The smoke mixes with the city air. As a result, people began to have breathing problems. Instances of asthma and other lung disorders began to increase.

Trees have been banished from cities. So, birds do not find places to build their nests. They also find the smoke in the city air troublesome. They are no longer sure of getting water when they are thirsty. So there are fewer and fewer birds in cities now. The number of butterflies and other insects is also falling.

Because of the increasing population, the drainage system in cities fails sometimes. Then water collects in the midst of living areas. Mosquitoes grow in it. They spread diseases like malaria, dengue, filaria, chikungunya.

Do you see how the increase in the population spoils the life we lead in cities?

Teacher's Note

In India, cities like Mumbai and Delhi are very crowded. Many people come to cities to find jobs. This makes it hard for everyone to get clean water, clean air, and good homes.

Exam Trick

Remember: More people mean more cars and smoke. More cars mean dirty air. Dirty air makes people sick. This is why we need to plant more trees in cities.

Points to Remember

When people move to cities, trees are cut down.
More vehicles make more pollution and smoke.
Smoke harms people and animals.
Birds and insects disappear from cities.
Dirty water spreads diseases.

This is a preview of the first 3 pages. To get the complete book, click below.