Class 6 Science Chapter 11 Notes Nature’s Treasures
Nature’s treasures refer to the resources provided by the natural environment that are essential for our survival and for making our lives comfortable. Nature’s treasures include air, water, energy from the Sun, soil, rocks, minerals, forests, and fossil fuels. Without these treasures of nature, any form of life on Earth is not possible.
Air
Air is nature’s treasure as it is essential for all living beings for their survival. The air which we breathe in has oxygen, which our bodies need to perform its functions and to live. Without air, plants and animals would not survive and we can survive without food or water for a few days, but we cannot survive without oxygen for even a few minutes. Air, which surrounds the Earth is not made up of a single gas but a mixture of many gases. Air mainly contains nitrogen (78%) and oxygen (21%). Together nitrogen and oxygen make up about 99% of the air. The remaining part (1%) of air consists of argon, carbon dioxide, and other gases in small quantities. The composition of air can be represented with the help of the diagram as shown.
Percentage, denoted by % is the number of parts in 100 like 21% oxygen in air means from the total of 100 parts of air, 21 parts contain oxygen gas. The composition of air is not the same everywhere. The higher mountain regions contain less oxygen levels than the plain regions. The air in industrial and urban areas has higher levels of carbon dioxide, smoke, and dust than the air in villages.
Wind
Moving air is known as wind. Wind helps to cool us down on hot days and is used to generate electricity in windmills. When the wind blows, it rotates the wings of a windmill. Windmills can be used to run flour mills (grind wheat into flour), and pull water up from a well. In India, there are many windmill farms, which are areas that have a large number of windmills. These farms use the energy of the wind to generate electricity, which helps to power homes and industries.
Kutch Wind Farm, in Gujarat, is one of the largest wind farms in India. Other windmill farms in India are Jaisalmer Wind Park in Rajasthan, Muppandal Wind Farm in Tamil Nadu, Brahmanvel Wind Farm in Maharashtra, etc.
Water
Water is one of nature’s most precious treasures because it is essential for all life on Earth. Water is found abundantly on the Earth, as about two-thirds of the total earth’s surface is covered with water. Most of the water is found in the oceans and seas and is saline or salty. Saline water is not directly usable, as it contains a large amount of salt, which is not fit for drinking, domestic, agricultural, and industrial use. Only a small amount of water on Earth is suitable for all these activities, which is called freshwater. It is present in rivers, lakes, ponds, ice sheets, snow, and groundwater. We need fresh water for drinking and many other activities, like cleaning, washing clothes and utensils etc. Freshwater present in ice sheets, snow, and underground water is difficult to access for doing these activities whereas, freshwater present in rivers, lakes, wells, and ponds is easy to access.
Responsibilities Towards Water
“Water is our responsibility before it is our right”. Even though we all have the right to use water, we must also take responsibility for it. This means we need to be careful not to waste water and to keep our water sources clean. If we waste water or pollute it, we might not have enough clean water for ourselves and others in the future. So, it is our job to use water wisely and to save it. Water gets polluted by human activities, which makes it unsafe for consumption by living beings. Some activities that lead to water pollution are
- Wastes from homes and industries are dumped into the water.
- Harmful chemicals from factories are sometimes dumped into rivers and lakes.
- Harmful chemicals containing fertilizers and pesticides used in farming can come into water bodies during rain.
- Throwing plastic and other garbage into rivers or lakes.
So, to reduce water pollution, we can dispose of chemicals properly, reduce plastic use, choose fertilizers that are safer for the environment, and restrict the throwing of garbage and plastics in the water bodies like rivers, lakes, etc. Also, water can easily be wasted through activities like leaving the tap running, over-watering plants, or using water carelessly. So, there is a need to conserve water as freshwater sources are limited and there is a shortage of water in many parts of India. We should conserve water and use it judiciously, by fixing leaks, turning off the taps when not in use, recycling water, and water harvesting.
Rain Water Harvesting
Water harvesting is a smart way to conserve water. In many homes, schools, and office buildings, rainwater is collected and stored in large quantities, which can be used later on for household chores, watering plants, etc. This method of conserving water is called rainwater harvesting.
In India, traditional water harvesting methods have been used for centuries. For example, in Rajasthan, people use stepwells, also known as Bawadi, and in Gujarat, they are called Vav. These are special wells with steps leading down to the water, making it easier to access. They are designed to collect and store rainwater as well as water that seeps in from nearby lakes, ponds, and rivers. The walls of these wells are lined with stones, allowing water to seep through and fill the well.
World Water Day is celebrated on March 22nd every year to remind us how important water is for our lives and our planet. It helps us understand that many people around the world do not have enough clean water to drink and use. World Water Day encourages people to find new ideas and solutions to solve water problems, like finding ways to clean polluted water or using water more wisely.
Energy from the Sun
The Sun is considered one of nature’s treasures because it is the main source of energy, that supports all life on Earth. The Sun provides heat and light, which are used by the plants to make food and grow. This in turn provides food and oxygen for animals and humans, as they eat plants for survival. It also helps in drying of clothes, warming up our homes in winter, brightening up our rooms during the day (so we don’t need to use electric lights), etc. The Sun also plays an important role in the water cycle thus, influences rainfall patterns. Without the Sun, our planet would be a cold, dark place where life could not survive.
In many households in India, water is offered to the Sun early in the morning as an expression of gratitude. Sunlight or solar energy is used to generate energy through solar panels. Solar panels are special devices that capture sunlight and convert it into electricity. This electricity can then be used to power homes, schools and offices. The Sun’s energy can be directly used for cooking in a solar cooker or for heating water in a solar water heater.
Forests
Forests are large areas covered with dense growth of trees, shrubs, and herbs. Forests play a crucial role in our environment.
- They produce oxygen, which is essential for humans and animals to breathe.
- Many products that we use in daily life like paper, wooden tables and chairs, etc., are also obtained from forests.
- Forests are a natural home for many species of plants and animals including, birds and insects and they provide food and shelter for them.
- Because of these uses, forests are considered a precious resource that needs to be protected and preserved.
Unfortunately over the years, forests have been cut down on a large scale, this process is known as deforestation. This loss of forests has serious consequences like loss of habitat for many species, which can result in the disappearance (extinction) of plants and animals.
The loss of forests can also disrupt the water cycle, leading to reduced rainfall and water shortages in some areas. Some ways to protect and preserve the forests are
- Reducing Deforestation: Follow practices that reduce the cutting down of trees. This includes using paper and wood products wisely.
- Reforestation: Planting new trees in areas where forests have been cut down which helps to restore lost forests.
- Spreading Awareness: Spread awareness about the importance of forests and encourage others to take action to protect them.
Van Mahotsav, which means “Tree Planting Festival,” is celebrated in India every year during the first week of July. This special week is dedicated to planting trees and plants and raising awareness about the importance of forests.
Chipko Movement was a special effort in India that started in the early 1970s to save trees and protect forests. In this movement, people, especially women, hugged trees to prevent them from being cut down. They formed human chains around the trees and refused to let go, showing how much they cared about the forests. Their brave actions helped stop the destruction of many trees and raised awareness about the importance of protecting forests for our environment. This movement showed how people can come together to make a big difference in preserving nature.
Soil, Rocks and Minerals
Forests have a variety of soils. Soil is called nature’s treasure because it is important for supporting biodiversity. It supports the growth of plants and supplies them with nutrients and water, which are essential for food production. It is also home to many tiny organisms, such as worms and insects. Decomposed and decayed plants and animals also become part of the soil.
Soils of different places may be of various colors, because these soils may contain different materials. It can be of different types, some soils can be good for growing crops, while some are good for making bricks. Soil forms through a process that takes thousands of years. It starts with the disintegration (breaking apart) of rocks into smaller particles by using the energy from the Sun, water, and living organisms. Rocks are naturally occurring solids composed of one or more minerals.
Uses of Soil, Rocks and Minerals
Some of the uses of rocks are the construction of houses, roads, temples, buildings, etc. Some rocks like granite and marble are popular for making durable and attractive table tops and floors, while limestone and sandstone are used in building walls and roads. Some rocks, like slate, are used for roofing, and laterite is used in making bricks. Rocks can also be used in making tools like hand axes and arrowheads.
The formation of rocks takes thousands to millions of years, so it is important for us to conserve the rocks and use them judiciously. Minerals are the building blocks of rocks and have distinct properties such as hardness, color, and shine. Important metals such as gold, silver, aluminium, copper, iron, etc., are extracted from minerals.
Minerals have a wide range of uses:
- Minerals like copper, silver, cobalt, and gold are essential in making electronic devices like phones and computers.
- Minerals like aluminium, iron, etc., are used in the making of airplanes and cars.
- Precious minerals like diamonds, gold, and silver are used to create beautiful and valuable jewelry.
Fossil Fuels
Fossil fuels are natural energy sources formed from the remains of plants and microorganisms buried deep inside the Earth, millions of years ago. They include coal, petrol, diesel, kerosene, and natural gas. Petrol, diesel, and kerosene are obtained from petroleum. These fossil fuels are used to generate electricity and they can also be used as a fuel for vehicles. Natural gas is a colorless gas, which is used in cooking and generating electricity. It is nowadays used in the form of Compressed Natural Gas (CNG) which is a cleaner fuel for vehicles, than petrol or diesel as on burning it produces less harmful substances and carbon dioxide, which causes global warming. Also, natural gas and Liquefied Petroleum Gas (LPG) have replaced the use of coal, wood, and cow dung as fuels for cooking in households. Fossil fuels such as coal, petroleum, and natural gas, are available in limited quantities and we will run out of them if we keep using them in the manner that we currently do, as it takes, millions of years for their formation.
Pollution Due to Fossil Fuels
Fossil fuels when burnt, produce smoke and carbon dioxide (CO2) gas, which significantly pollutes the air and the released carbon dioxide is a major greenhouse gas, which causes global warming. The overuse of fossil fuels has led to serious air pollution problems. For example, cars, buses, and trucks that run on petrol or diesel emit pollutants. Similarly, burning coal for domestic use also releases pollutants into the air. This pollution can have harmful effects on health causing respiratory problems like asthma and bronchitis. It can also contribute to global warming leading to climate change and extreme weather conditions. Reducing our dependence on fossil fuels and finding alternative energy sources is essential for improving air £ quality and protecting both human and environmental health.
Natural Resources: Renewable and Non-renewable
Resources are the substances that fulfill our needs and are essential to sustain our lives. Resources can be classified into two main types, natural resources and man-made resources.
- The resources which we get from nature are called natural resources.
Examples of natural resources are air, water, minerals, sunlight, forests, soil, rocks, fossil fuels, etc. - The resources that are created by human beings are called human-made (man-made) resources.
For example, plastic, cars, roads, machines, electric bulbs, solar panels, etc.
Natural resources are again classified into two categories based on their availability in nature.
Renewable Natural Resources:
The resources that get renewed, replenished, or restored within a reasonable period of time are known as renewable natural resources. These are also known as inexhaustible natural resources. Examples of renewable natural resources are water, air, sunlight, etc.
Non-Renewable Natural Resources:
The resources that are found in nature in limited amounts and once used, get exhausted are called non-renewable resources. They are not produced or replenished within a short period. They are also called exhaustible natural resources. Examples of non-renewable natural resources are coal, natural gas, petroleum, minerals, soil, rocks, etc.
Conservation of Natural Resources
Conservation and responsible use of natural resources are essential to ensure their availability for future generations. Natural resources like water, fossil fuels, and forests, are limited and essential for our consumption and survival. By conserving these resources, we help to preserve the environment and ensure that they will be available for future generations. The practices we can follow to conserve natural resources are
- Recycling and reducing waste
- Planting trees
- Use of fossil fuels should be minimized as it is a non-renewable natural resource and burning of these fossil fuels causes air pollution and impacts global warming.
- Alternative energy sources, like solar energy, wind energy, etc., should be used instead, as they are renewable resources.
- “Earth provides enough to satisfy every man’s need but not for every man’s greed.” – M. K. Gandhi
→ Air: It is a mixture of many gases mainly nitrogen (78%) and oxygen (21%).
→ Rainwater Harvesting: The process in which rain water is collected and stored in large quantities, which can be used later on for household chores, watering plants, etc.
→ Forests: Large areas covered with a dense growth of trees, shrubs, and herbs.
→ Rocks: Naturally occurring solids composed of one or more minerals.
→ Minerals: Naturally occurring inorganic substances with a specific chemical composition and structure.
→ Fossil Fuels: Natural energy sources formed from the remains of plants and microorganisms buried deep inside the Earth, millions of years ago.
→ Resources: The substances that are valuable and useful to humans.
→ Natural Resources: The resources which we get from nature.
→ Human-made Resources: The resources that are created by human beings.
→ Renewable Natural Resources: The resources that get renewed, replenished or restored after use within a reasonable period.
→ Non-renewable Natural Resources: The resources that are found in nature in limited amounts and once used, they get exhausted. They are not produced or replenished within a short period.