Introduction
Natural
resources are derived from the environment. People depend on natural resources
for their survival. Natural resources can be the land, the soil, the water, the
air, the plants and the animals. All life on earth depends on four vital
natural resources such as air, water, soil and sunlight. Some resources that can be replaced after use
by natural processes are called renewable. The common examples include air,
water, soil, living organisms and sunlight.
Natural resources that cannot be replaced are termed non-renewable.
Fossil fuels are an example of non-renewable natural resources. Non-renewable
resources exist in a fixed amount and can be replaced by processes that take
millions of years. Extracting, processing and using natural resources create
pollution of air, water and land. But sustainable conservation is using natural
resources wisely and not contributing to any environmental pollution.
Definition of natural resource
A resource
is a form of matter or energy which is essential for the functioning of
organisms, populations and ecosystems.
In other
words, natural resources are the materials or substances obtained from nature
which are required for the survival and prosperity of human beings.
Types of natural resources
Natural
resources can be classified on the basis of their origin as abiotic and biotic
resources.
Abiotic resources are derived from the non-living
world. e.g. land, water, air.
Biotic resources are derived from living organisms.
E.g. fish, forests.
Natural
resources are mostly classified on the basis of their continual utility as
renewable and non-renewable resources.
Renewable natural resources – Renewable resources are natural
resources that can be replenished naturally in a short period of time. These
resources are inexhaustible in supply. These resources have the ability to
regenerate within a few years or decades. Renewable resources are vulnerable to
human abuse. E.g. freshwater, oxygen, trees and fish. Renewable natural
resources can be either organic (e.g.
plant and animal species) or inorganic
renewable natural resources (e.g. water, air)
Non-renewable natural resources – A non-renewable resource is a
natural resource that cannot be re-made or re-grow at a scale comparable to its
consumption. They are fixed in quantity and can be depleted. They take very
long time to form. The replenishment time may range from 100s to million
years. The extraction of non-renewable
resources always damages the environment. Coal, oil and natural gas are
considered non-renewable because they take million of years to form. They are
the product of the fossilized remains of dead plants and animals that have been
exposed to heat and pressure deep within the earth’s crust. Hence these
resources are called fossil fuels. E.g. metals, minerals and fossil fuels.
Non-renewable
natural resources can be subdivided into recyclable and non-recyclable
resources.
Recyclable natural resources are those that can be collected after
their use and can be recycled for future requirements. E.g. metals.
Some natural
resources are called non-recyclable
because they cannot be recycled after their use. E.g.fossil fuels, natural
energy.
All natural
resources can also be classified on the basis of their natural amounts of availability
into two categories:
1.
Inexhaustible
natural resources
2.
Exhaustible natural resources
Inexhaustible natural resources are available in huge amounts in the
nature and are replenished after their consumption. E.g. solar energy, wind power, rain fall,
tidal power and hydropower.
Exhaustible natural resources are available in limited amounts in
the nature and are not replenished at the same rate as consumption. E.g. fossil
fuels, metals and minerals.
Natural resources
can also be classified into potential and actual natural resources based on
their stage of development.
1.
Potential
natural resources
2.
Actual natural resources
Potential natural resources – are the resources which are found
in a region whose quality and quantity have not been determined for
utilization. They can be used only in the future. E.g. Distribution of mineral oil wealth in India.
Actual natural resources – are the resources whose quality
and quantity have been determined for utilization and are being used in the
present time. E.g. availability of oil and natural gas from Mumbai offshore
region.
Flow natural resources – It does not remain in one location
and moves about because of natural actions in the physical environment. It is
replaced by natural processes whether humans use them or not. The quantity is
expressed in annual rates. E.g. solar energy, freshwater, waves and tides.
Stock natural resources – It can be permanently expended
and whose quantity is usually expressed in absolute amounts. E.g. coal and
petroleum deposits.
Forest resources
Forests are
a highly valuable and most abundant resource. They are diverse in composition
and density. Forests cover about 30% of the earth’s surface. They are inhabited
by a variety life forms. Forests have
warm climate with adequate rainfall.
Forests have tall and dense trees with many wild animals. The soil of
the forests is rich in organic matter and nutrients. Forests play a major role
in the water cycle, which includes circulation, transformation and
replenishment of freshwater from all of earth’s ecosystems. Forests are
essential for the conservation of biodiversity, water and soil resources.
Forests contribute substantially to the economic development of a country. Forests
are usually defined as land areas dominated by trees, where the tree canopy
covers at least 10% of the ground area. A
healthy forest is composed of many more unique ecosystems. Over two – thirds of
known land-based species live in forests.
In other words forests are home to 50-90% of earth’s species. In many
countries, forests are the primary targets for agricultural and urban
expansion.
Importance of forests
Forests are
an important renewable natural resource.
Forests are the natural wealth of a country. They are the store houses
of biodiversity. Forests provide various goods and services and also maintain
the life-support systems of the earth.
Forests provide approximately 1.6 billion people with food, medicines, fuel and
other basic necessities. Forests have the following three types of functions:
1.
Productive
functions – Forests yield timber, bamboos, food and a variety of products such
as alkaloids, essential oils, resins, latex, rubber and medicines.
2.
Protective
functions – Forests conserve soil and water. They prevent drought and protect
against wind, cold, heat, radiation and noise.
3.
Regulative
functions – Forests absorb, store and release gases, water, minerals and sun
light. They regulate floods, droughts and biogeochemical cycles.
Deforestation
Deforestation is the direct human-induced conversion of forest to non-forest
land use such as agriculture, grazing or urban/industrial development.
Deforestation is defined as the destruction of forest due to over-cutting of
trees.
Effects of deforestation
Deforestation causes irreversible environmental damage. Deforestation
accelerates extinction of plants, animals and microbes. Deforestation disrupts
cloud formation and rainfall. Deforestation threatens the livelihoods of tribal
communities.
Deforestation increases soil erosion and decreases soil fertility.
Deforestation increases greenhouse gases and warming of the environment.
Conservation and management of
forests
An increase in forest area is initiated by the following ways:
1.
Afforestation
programmes- planting of trees on land that was not previously forested.
2.
Reforestation
programmes- re-establishment of forest formation.
3.
Conservation
of reserve forests - forests are protected in National parks, Sanctuaries,
Sacred Grooves and Biosphere reserves.
4.
Chipko
movement – This tree hugging movement was first started in Tehri Garhwal
district in Uttarkhand in 1972. The movement was popularized by Sunderlal
Bahuguna . Under this campaign, people started hugging trees whenever forest
contractors tried to cut the trees.
5.
Production
or commercial forestry – includes three programmes i.e. social forestry, agro
forestry and urban forestry.
Mineral resources
Minerals are
a major form of non-renewable resource. A rock is an aggregate of minerals. Minerals
are formed over a period of millions of years in the earth’s crust. Mineral are
naturally occurring inorganic compounds of definite chemical composition and
characteristic physical properties.
A mineral
can be defined as a pure element or chemical compound that is normally
crystalline and that has been formed as a result of geological processes.
There are more than 3,500 known minerals.
Minerals range in composition from pure elements and simple salts to very complex
silicates. The study of minerals is called mineralogy. Global distribution of
minerals is not uniform. Minerals can be grouped into two broad categories:
1.
Metallic minerals – These mineral are found in the
form of ores. The metal ores contain several impurities. E.g. iron, copper,
gold and lead.
2.
Non-metallic minerals – these minerals are composed of
elements like silicon, oxygen, calcium, magnesium, iron, aluminium etc. E.g quartz, graphite, feldspar, dolomite, calcite,
laterite, diamonds, sulphur, potash, salts, coal and petroleum.
Conservation of mineral resources
1.
Recycling
– minerals in products can be recycled.
2.
Reuse
– the reuse products more economical
3.
Substitution
– scarce minerals can be substituted with more abundant minerals.
4.
Decreased
consumption – consumers can decrease their mineral consumption.
5.
Use
of industrial waste – one industry may use the waste products of another
industry.
Water resources
Water is a renewable
and limiting resource. It covers approximately 71% of the planet earth and constitutes
60-70 weight % of the living world. About 97.5 percent of the water on earth is
strongly saline (sea water) the remaining 2.5 percent is freshwater. Pure,
usable freshwater is only 0.3 percent.
Freshwater is therefore, a treasure to protect and conserve. Water is a unique molecule because it is the
only natural substance that exists in three physical states like liquid, solid
(ice) and gas (steam) on earth. Water
is often referred to as a universal solvent because it has an unusual ability
to dissolve other chemical substances. Water is the cellular medium within
which all biochemical reactions can occur in living organisms. It is the
transport medium for food, oxygen and other things needed by cells. Water is
one of the vital elements for human life. The total amount of freshwater on
earth is 1.4 billion cubic kilometres, but only around 41000 km3 circulates
through hydrologic cycle. All the freshwater on earth comes from the rainfall.
The amount of rainfall that falls on the continents is finite.
Sources of freshwater resources
Surface
water – the freshwater exists in surface water bodies like streams, lakes,
ponds, wetlands and man-made reservoirs. It is the most important resource of
freshwater available for agricullure, industrial and domestic uses. The surface
water flows in our country through 14 major rivers viz. Indus, Ganga,
Brahmaputra, Godavari, Mahanadi, Krishna, Cauveri, Tapti, Mahi etc.
Ground water
- the freshwater, which is received through rainfall, infiltrates into the soil
and supplements underground water reserves. The hydrologic data suggests that
the annual rainfall in India is about 400 m ha m. According to an estimate
about 9.86% of the total freshwater resources are in the form of ground water.
Of all freshwaters, ground water is less likely to be get polluted.
Integrated water
resources management (IWRM)
IWRM
has been defined as “a coordinated, goal-directed process for controlling the
development and use of river, lake, ocean, wetland and other water assets”. It
is a comprehensive approach for implementing efficient, equitable and
sustainable solution to water and development problems.
Sustainable water management
1.
Construct dams
and many small reservoirs.
2.
Develop small
catchment dams and protect wetlands.
3.
Desalinize sea
water into usable water.
4.
Divert freshwater
canals/rivers to dry areas.
5.
Dredge and desilt
rivers and water bodies regularly.
Food resources
Food
is one of the basic needs of every living organism. Good food is indispensable
for health and well being of humans at all stages of life. The food is composed
of organic molecules such as carbohydrates, proteins and fats. The body uses
some of the molecules in food to function correctly and stay healthy. The key
to good health lies in maintaining balanced nutrition. The
major source of human food includes plants or plant products and animal
products. The plant products include cereals, pulses, vegetables fruits and
spices. The animal products constitute milk or milk products, eggs and meat. Agricultural
crops constitute an important food
resource. About 300 crops are grown for food and only 100 are used on a large
scale.
Of
the earth’s 30,000 plants with edible parts, we eat only about 30 plants. Of
this only 15 plants and 8 animal species supply 90% of our food. Four crops
such as wheat, rice, corn and potato make up more of the world’s total food
production than all others combined. Grain provides about half the world’s
calories with 2/3 people eat mainly vegetarian diet. As incomes rise, people
consume more animal proteins in the form of meat, eggs, milk, cheese and other
products of domesticated live stock. Fruits and vegetables also make a large
contribution to human diet. They contain high levels of vitamins, minerals,
dietary fibre, and complex carbohydrates. Domesticated
animals form an important food source. The major domesticated animals used as
food are ruminants such as cattle, sheep, goats, camel, reindeer etc.
Negative
Impact of modern agriculture
1.
Declining genetic diversity – leads to loss of genetic
diversity of indigenous crop varieties. Selective farming
causes unformity of crops, monocultures and disease outbreaks.
2.
Soil erosion – Clearing
land for farming may result in soil erosion.
3.
Salinization of soil – soil builds up salt concentration due
water logging. Intensive farming reduces soil fertility and productivity.
4.
Desertification – over-grazing is responsible for
desertification.
5.
Fertilizer pollution – excessive accumulation of nitrates and
phosphates is soil. Rainwater run off cause eutrophication of surface water bodies and contamination of
ground water.
6.
Pesticide pollution – over use of herbicides and insecticides
cause chemical contamination of soil; pesticides can enter food chains;
pesticides kill beneficial soil organisms.
7.
Other impacts – farming takes up land and reducing habitats
and wildlife; irrigation (watering of crops) may take too much of water from
rivers and deprive downstream habitats of water.
Sustainable
Agriculture
A sustainable agriculture must be
economically viable, socially responsible and ecologically sound. An
agriculture that uses up or degrade its natural resource base or pollutes the
natural environment eventually will lose its ability to produce. Such
agriculture is not sustainable.
World food problems
In
1960s, the Green Revolution and advances in technology greatly increased the
food production in many countries. There is a saying that “there is plenty of
food on the planet, it is just a problem of distribution.” Global demand for
food increased as a function of population growth for several decades. At one
stage, the world human population surpassed the global food production. After
2001, the agriculture around the world was drastically affected by extreme
weather conditions. Diseases affecting the crops and livestock have devastating
effects on food production. By 2006, world cereal production has fallen by 2.1
percent. The prices for basic foods such as rice, wheat, and corn have risen 83%
since 2005. Many countries experience perpetual food shortages. This results in
widespread hunger and malnutrition.
Food security – refers to the availability of food and
one’s access to it. Food security is the availability of enough food and access
to all people at all times for an active and healthy life. The WHO defines
three facets of food security:
1.
Food availability
– availability of sufficient quantities of food on a consistent basis.
2.
Food access –
sufficient household income to obtain appropriate foods.
3.
Food use – access
to safe water, good sanitation and basic health care can make a difference in nutritional
well being. They have an impact on body’s ability to utilize consumed foods.
Land
resources
Land is one
of the major life supporting systems. Land occupies 38% (one fifth) of the total earth’s
space. Soil covers about
four fifth of the land area. Soil is a biologically active,
complex mixture of minerals, organic materials, living organisms, air and
water. Soil is an interface between biosphere, lithosphere, hydrosphere and
atmosphere. Soil is the outer most layer of the earth’s crust (Earth’s living
skin-1/3 of surface).
Soil is a vital resource that provides food, feed, fuel and
fiber.
Soils have four major components: mineral matter, organic
matter, air, and water. Mineral matter contains three fractions, sand, silt,
and clay. Organic matter contains appreciable quantities of nitrogen,
phosphorus and sulfur. Air and water occupy the pore spaces in soils. A fertile soil is a living soil
containing billions of living organisms in every cubic centimetre. Plant
nutrients in the soil are regularly regenerated by decay, decomposition and
mineralization of organic matter by living organisms. Living communities in the
soil are the basis for its fertility and other properties, which promote
healthy plant life. Depletion of soil fertility is caused by removal of
vegetation, water logging and application of non-degradable chemicals.
Sustainable Soil Conversion
1.
Conservational tillage – ploughing improves soil permeability, soil moisture
and nutrients.
2.
Organic farming – More organic inputs to soil.
3.
Crop rotation – growing legumes after cereal crops.
4.
Contour ploughing – ploughing with alternate furrows and ridges.
5.
Mulching – Soil is allowed to remain united and is covered with plant litter.
6.
Strip cropping – planting in rows or strips.
7.
Terrace farming – Hill slope is converted into terraces.
8.
Agrostological methods – Grasses are
grown in rotation or along with agricultural crops.
9.
Afforestation – Trees or wind breaks are
planted in deserts.
Air resources
Air
is one of the natural resources and is a life-supporting system. Air is one of
the basic needs of life. It forms the immediate environment of the earth and
biosphere. The “air” is actually a mixture of gases. For example, 78% of the atmosphere is made of the nitrogen
gas, 21% is composed of oxygen, and 0.9% is made up of argon. The atmosphere
contains gases, suspended liquids, and solids that entirely surround the earth.
The earth's gravity pulls these gases, liquids, and solids toward the surface.
The
composition of air is not fixed. It changes according to the time of the day,
the conditions of environment and humans’ activities. Air pollution refers to
the presence of foreign particles in air which can affect the quantity of air
and the health of living things. Carbon dioxide is supplied into the atmosphere
by plant and animal respiration, the decay of organic material, volcanic
eruptions, and natural and anthropogenic combustion. Carbon dioxide is removed
from the atmosphere by photosynthesis. CO2 is an important greenhouse gas.
Uses of air resource
1.
Organisms can respire oxygen and
survive in the world.
2.
Rainfall in any area depends on wind
or air current.
3.
Wind has been used to generate
electricity.
4.
Ozone protects the earth from uv rays.
5.
Nitrogen is an important mineral
nutrients for plants.
6.
Air acts as a medium for some
microorganisms.
7.
Water vapour maintains atmospheric
humidity and in precipitation.
Energy resources
Energy is the capacity to do work i.e.to
move matter. Energy is our most important resource. Energy availability may
limit economic and population growth. Most of our energy comes from fossil
fuels. Sun is the primary source of energy. According to the first law of thermodynamics,
‘energy and matter can neither be created nor destroyed’. The second law
defines that, ‘energy cannot be completely recycled’. Life depends on energy
flow through ordered structures of matter.
Energy comes in different forms such as
heat (thermal), light (radiant), mechanical, electrical, chemical and nuclear
energy. There are two types of energy:
1. Potential energy – stored energy
2. Kinetic energy – working energy
Energy is produced usually from fuel
burning and atom splitting. Heat is
considered to be low quality energy because it is dispersed. It is commonly a
by-product of mechanical work. Electricity is a high quality form of energy
because it can be transported through
wires, stored in batteries and used to make other forms of energy.
Kinds
of energy resources
Energy resources can be classified into
two groups:
1. Primary energy resources
2. Secondary energy resources
Primary energy is an energy form found
in nature. Secondary energy refers to
all sources of energy those results from the transformation of primary energy
resources. For example electricity is a secondary energy obtained from burning
coal in a thermal power plant. Primary energy resources can be subdivided into
two forms as:
i.
Non-renewable energy resources
ii.
Renewable energy resources
The energy
sources can also be classified into conventional and non- conventional energy
sources.
Conventional energy sources – energy sources which we are using it for a long time at a
commercial scale. e.g. fossil fuels and hydroelectric power.
Non-conventional energy sources – energy sources which are in the process of development over the
past few years. They are available in plenty and can be replenished naturally.
E.g. solar, wind, tidal, geothermal and biomass.
Non-renewable
energy resources
A non-renewable energy can be defined as
a resource that cannot be reproduced or re-made at a scale comparable to its
consumption. Once depleted, there will be no more available for future use. For
example fossil fuels (coal, petroleum and natural gas) take thousands of years
to form naturally and cannot be replenished in a short period of time. Impurities in fossil fuels are a major source
of pollution. The burning of fossil fuels produce large amounts of carbon
dioxide, which contributes to global warming.
Renewable
energy
Renewable energy resources can be
defined as the resources that are naturally replenished, inexhaustible in
duration but limited in the amount of energy that is available per unit of
time. Renewable energy is obtained from natural resources such as
sunlight, wind, tides, waves and geothermal heat. Common applications of
renewable energies are electricity generation and motor fuels. Renewable energy
resources currently contribute to approximately 18% of total global energy
consumption. Examples include:
1. solar energy ,
2. hydro power,
3. tidal power,
4. wind energy and
5. geothermal (energy from the heat inside the earth).
Sustainable
conservation of natural resources
Sustainability is a state of
balance between resource use and the regenerative capacity of the earth. It can
be described as ‘securing quality of life within the limits of nature’. The
sustainability can be defined as “forms of progress that meet the needs of the
present without compromising the ability of future generations to meet their
needs”(Our Common Future 1987 : The World Commission on Environment and
Development). Achieving sustainability is a balancing act between current needs
and future needs.
Sustainability lies in the
interplay of environmental quality, economic vitality and social equity.
Ecological sustainability is the maintenance of life support systems and the
achievement of natural extinction rate of species. Environmental sustainability
refers to the maintenance of natural capital (e.g. natural resources).
The measures for sustainable conservation
Stabilizing
population growth- The over-growth of human population
has been a critical factor in over-utilizing the natural resources. Human race
must willingly practice population control. Population should be stabilized at
the level of carrying capacity of the planet earth.
Change-over
in energy use- A
change-over is necessary from non-renewable polluting energy to renewable and
non-polluting alternative energy resources.
Change
– over in technology -A change-over is needed from resource
intensive and population – prone technologies to environmental – friendly
technologies.
Change–over
in economy -The economic development must be
environmentally sensitive and sustainable.
Scientific
conservation - Conservation is the ‘gospel of efficiency’.
Scientific methods should be followed to manage nature and natural resources
efficiently.
