Nature's Treasures

Why This Matters

Take a deep breath in. Now let it out.

You just used a treasure of nature — air.

Look around you for one more minute. The water you drink. The soil that grows your food. The wood in your chair. The metal in your spoon. The Sun that warms your morning. None of these were made in a factory. Nature gave them all to us, for free.

We call these gifts natural resources. A natural resource is anything we get from nature and use for our life. Air, water, soil, plants, rocks — all are natural resources.

Here is the big worry. Some of these gifts can run out. Once they are gone, they are gone. So we must learn what they are, where they come from, and how to use them with care.

In this chapter you will meet nature’s treasures one by one. You will learn which ones come back quickly and which ones never come back. And you will learn simple ways to save them — for you, and for the children who come after you.

The Big Idea

Everything we need to live comes from nature. Air, water, soil, the Sun, forests, rocks and minerals are all natural resources — gifts of nature that we use. Some resources, like air, water and forests, come back on their own in a short time. We call these renewable. Others, like coal and petroleum, take millions of years to form. Once we use them up, they cannot come back in our lifetime. We call these non-renewable. Because some gifts can run out, we must use all of them with care. Use less, waste nothing, and save some for the future.

Let’s Break It Down

Nature’s gifts — air, water, soil, minerals, forests

Let us meet nature’s main treasures, one by one. For each one, ask the same simple question: what does it give us?

Air. Air is all around us. We cannot see it, but it is there. The air is a mix of gases. Most of it is a gas called nitrogen (about 78 parts out of 100). A gas called oxygen makes up about 21 parts out of 100. We breathe in air to get oxygen. Our body needs oxygen every minute to stay alive. You can live a few days without food, but you cannot live even a few minutes without air. Moving air is called wind. Wind can spin a firki (a paper pinwheel). The same wind spins the big blades of a windmill to make electricity.

Water. We need water to drink, to cook, to bathe, and to wash. Farmers need water to grow crops. Water covers most of the Earth. But most of that water is in the seas, and sea water is salty. We cannot drink salty water. The water we can use is freshwater — found in rivers, lakes, ponds and under the ground. Only a small part of all water is freshwater we can reach easily. So freshwater is precious.

Soil. Soil is the loose, dark layer on top of the ground. Plants grow in it. Their roots hold tight to the soil and drink water from it. Soil is full of life — tiny worms, insects, and living things too small to see. Soil takes thousands of years to form, as rocks slowly break into tiny bits. We learn more about soil in the next part.

Rocks and minerals. Rocks are the hard stones we see in the ground and hills. We use rocks to build houses, roads, dams and temples. Rocks are made of minerals. A mineral is a useful material found in the earth. From minerals we get metals like iron, gold, copper and aluminium. These metals are used to make cars, planes, wires, and even your mobile phone. Like soil, rocks and minerals take a very, very long time to form.

Forests. A forest is a large area full of trees and plants growing close together. Forests give us wood, fruits, and medicines. They are also the home of wild animals, birds and insects. The trees give the animals food and shelter. Forests do one more quiet job: the roots of the trees hold the soil and stop it from washing away.

And above all of them is the Sun. The Sun is the main source of energy on Earth. It gives us heat and light. Plants use sunlight to make their food. Animals eat the plants. So, in the end, almost all our energy comes from the Sun.

Figure 11.1 below brings all these treasures together, with what each one gives us.

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So every treasure has a job in our life. Lose any one of them, and life becomes hard. That is why we call them treasures.

Soil and its types

We said soil is where plants grow. But not all soil is the same. If you dig up soil from different places, it feels different. Some soil feels rough, like sand at the beach. Some feels sticky and smooth, like wet clay. Why the difference?

It is all about the size of the grains in the soil. Grains are the tiny bits that make up soil. There are three main kinds of soil.

Sandy soil has big grains. Because the grains are big, there are wide gaps between them. Water runs straight through these gaps and drains away fast. So sandy soil stays dry. It is like trying to hold water in a basket full of marbles — it leaks out at once.

Clayey soil has very tiny grains, packed close together. There are almost no gaps. So water cannot drain through. The water just sits on top. Clayey soil stays too wet. It is sticky and heavy.

Loamy soil is a mix. It has big grains (sand), tiny grains (clay), and medium-sized grains called silt, all together. So it has medium gaps. It holds some water but lets the extra water drain. Loamy soil also has humus in it. Humus is the dark, rotted bits of dead plants and animals in the soil. Humus is full of nutrients — the food that plants need to grow. That is why loamy soil is rich and fertile. It is the “just right” soil.

Here is the “nothing is a given” question. NCERT tells us loamy soil is best for most crops — but why? To understand it, recall one thing about plants.

Now the answer is easy. Roots need both water and air. Sandy soil holds almost no water — the plant goes thirsty. Clayey soil holds too much water and leaves no room for air — the roots cannot breathe, like a plant left standing in a bucket of water. Loamy soil is the in-between mix. It keeps enough water for the roots and still has air gaps. That is why loamy soil is best for growing most crops. Figure 11.2 below shows all three soils side by side.

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Let us put the three soils in one table so the difference is clear.

Renewable vs non-renewable resources

We have seen many natural resources. Now we sort them into two groups. The question we ask is simple: can nature make this resource again quickly, or not?

Renewable resources are the ones nature makes again, in a short time. After we use them, they come back on their own. Think of air — we breathe it, and plants keep filling it with fresh oxygen. Think of water — rivers flow again after rain. Think of forests — a cut tree can be replaced by a new tree that grows in a few years. Sunlight and wind also come every day. So air, water, forests, sunlight and wind are renewable.

Non-renewable resources are the ones that do not come back quickly. They took so long to form that, once we use them up, they are gone for our whole life and many lives after. Coal, petroleum (the oil that gives us petrol and diesel) and natural gas are non-renewable. So are minerals and rocks. Figure 11.3 below sorts the main resources into the two groups.

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Now the most important “why” of this chapter. Why are coal and petroleum called non-renewable? Because of how slowly they form. Let us see the story.

Coal, petroleum and natural gas are called fossil fuels. A fossil fuel is a fuel made from the buried remains of living things from long, long ago. Here is how they formed, in three steps:

1. Long, long ago, living things died and got buried. Coal formed mostly from big land plants that fell and got buried in swamps. Petroleum and natural gas formed from tiny sea plants and sea creatures that died and sank to the bottom of the seas.
2. Layer after layer of mud and sand piled on top of them. They got buried deep under the ground. There was heat down there, and the heavy layers pressed down hard.
3. Over millions of years, that heat and pressure slowly changed the buried remains into coal, petroleum and natural gas.

Figure 11.4 below shows these three steps.

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Do you see it now? It takes millions of years to make coal and petroleum. But we are burning them very fast — in our cars, buses, trucks and factories. Nature cannot make them again that quickly. So they will run out. That is exactly why they are non-renewable, and why we must save them.

Let us compare the two kinds of resources side by side.

Now let us practise sorting resources into these two groups.

Why and how we must conserve resources

We have learned something serious. Non-renewable resources like coal and petroleum will run out. And even renewable resources like freshwater and forests can become short if we waste them or use them too fast.

So we must conserve our resources. To conserve means to use carefully and not waste. Saving resources is everyone’s job — yours too.

Why does it matter so much? Because the resources are not only ours. They belong to the people who come after us — your younger cousins, and their children. If we use everything up now, they will have nothing left. Using resources wisely, so that there is enough left for the future too, is called sustainable use.

There is a saying often attributed to Mahatma Gandhi: “Earth provides enough to satisfy every man’s need, but not for every man’s greed.” In simple words: there is enough for what we need, but not enough if we are greedy and waste.

So what can we actually do? Here are simple habits anyone can follow:

• Save water. Close the tap while brushing your teeth or soaping your hands. Fix taps that leak — a dripping tap wastes a lot of water. Collect rainwater (this is called rainwater harvesting).
• Save electricity. Switch off lights and fans when you leave a room. Use daylight from the window in the daytime. Saving electricity also saves the coal that is burnt to make it.
• Reduce. Use less. Buy only what you really need. Less use means less waste.
• Reuse. Use a thing again instead of throwing it. Carry a cloth bag instead of a new plastic bag each time. Use an old glass jar to store things.
• Recycle. Send old paper, plastic, glass and metal to be made into new things, instead of throwing them away.

The last three — Reduce, Reuse, Recycle — are called the three R’s. They are an easy way to remember how to save resources. Figure 11.5 below shows all these ways together.

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Common Mistakes

Quick Check

Practice Problems

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Summary

• A natural resource is anything we get from nature and use in our life, like air, water, soil, the Sun, forests, rocks and minerals.
• Air gives us oxygen to breathe and wind. Water is for drinking, cooking and crops, but only freshwater can be used and it is limited.
• Soil is where plants grow, rocks and minerals give us metals and building stone, and forests give wood, fruit, medicine and homes for animals. The Sun is the main source of energy.
• There are three soil types: sandy (big grains, drains too fast), clayey (tiny grains, too wet) and loamy (a mix). Loamy soil is best for most crops because it holds enough water and still keeps air for the roots.
• Renewable resources (air, water, forests, sunlight, wind) come back quickly by nature. Non-renewable resources (coal, petroleum, natural gas, minerals) take millions of years and run out once used.
• Coal, petroleum and natural gas are fossil fuels. They are non-renewable because they formed from buried living things over millions of years and cannot come back in our lifetime.
• We must conserve resources: save water, save electricity, and follow the three R’s — Reduce, Reuse, Recycle — so there is enough left for the future too.

What’s Next

You have explored the treasures right here on Earth — its air, water, soil and the energy from the Sun. But the Sun is only one of countless lights in the sky. In Chapter 12, Beyond Earth, you will look up and out — at the Moon, the planets, the stars, and our place in the vast space around us.