MARIAN LIBRARY: ENVIRONMENTAL MANAGEMENT-Unit 1

UNIT 1

ECOLOGICAL EQUILIBRIUM AND SUSTAINABLE DEVELOPMENT

1.0 INTRODUCTION

Sustainable development is the method of using resources strategically, so as to retain them for the future. The term was used by the Brundtland Commission which coined what has become the most popular definition of sustainable development as development that 'meets the needs of the present without compromising the ability of future generations to meet their own needs.' In this unit, you will study about the concept of sustainable global development in detail. You will be familiarized with ecology, ecological balance and about the issues affecting ecological equilibrium. The unit will deal with problems such as population growth, natural resources and their depletion, industrial and urban population, and global warming. Along with a detailed discussion of the topics mentioned, the unit will also discuss the ways to overcome these problems.

1.2

SUSTAINABLE GLOBAL DEVELOPMENT

Sustainable development is the development that meets the needs of the present without jeopardizing the needs of the future generations. In other words, every generation should leave air, water and soil resources pure and unpolluted. Although it is a difficult proposition, it can be achieved through proper environmental management. Sustainable development has three important interdependent components, which are as follows:

(i) Economic development: Utilization of natural resources for cultivation,

industrialization, creating job opportunities and raising quality of life.

(ii) Social development: Providing basic needs like food, clothes, shelter,

health, education, etc.

(iii) Environmental protection: Providing clean water, air, soil, i.e., safe

environment to the present as. well as the future generations.

Human civilization through their excellence in scientific and technological fields has reached a level where they can produce more of their own kinds by cloning, exploit lands of other planets and receive information from any part of the world. However, at the same time, human civilization is facing the greatest challenge for survival due to the catastrophe created through environmental degradation.

To meet the basic requirements of ever increasing population, industrialization is a must, but it results in pollution, environmental degradation and causes ecological imbalances. At the same time, industrial development cannot be sacrificed as it creates job opportunities, raises the standard of living and solves unemployment problems. In view of this, a balance has to be struck so that development and environmental protection can occur simultaneously. To achieve this goal, sustainable development is the only answer. Development can take place if the following concepts are taken care of:

. Control of population growth

. Reduction in excessive usage of resources and enhancing resource

conservation, i.e., continuous use of renewable resources and protection of

non-renewable resources from wastage and rapid depletion

. Recycling and reuse of materials for waste minimization

. Scientific management of renewable resources, especially bio-resources,

which have a life cycle and inherent sustainable qualities

However, without proper social and economic development, sustainable development cannot he achieved. In order to do so, we will have to eradicate poverty through almost equal distribution of resources, support social justice and equality.

1.3

ECOLOGICAL EQUILIBRIUM

Ecology is a branch of science that deals with the interrelationship between biotic (living) and abiotic (non-living) components of nature, as well as with the relationship

among the individuals, population and community of the biotic components.

The term 'ecology' is derived from two Greek words-oikos (meaning house) and logos (meaning study of)-and is used to denote the relationship between the organisms and their environment.

Ecology has been defined in a number of ways. According to Woodbury (1954), 'Ecology is a science which investigates organisms in relation to their environment.' E.P. Odum (1969) defined ecology as 'the study of structure and function of nature'. The most acceptable definition of ecology was proposed by Charles Krebs (1985), who maintained: 'Ecology is the scientific study of the interaction that determines the distribution and abundance of organisms. '

In ecology, the term 'habitat' is used to denote the place where the population of an organism or species lives, for example, a pond. The pond is the habitat of zooplankton and fish. 'Niche' is the fundamental unit of the population of an organism or species in the community. Whereas 'habitat' is the place where an organism lives, 'niche' is the activity (functional) aspect of the organism. 'Population' is used to denote groups of individuals of anyone kind of organism and' community' or biotic community includes all the populations of a given area, called habitat.

Ecology plays a significant role in our day-to-day life. It is concerned with agriculture, horticulture, conservation of soil, forest, wildlife, water resources, etc.

Objectives of ecology

The importance of ecology is due to the presence of man in the ecosystem. Man interacts not only with its own species, but also with other living organisms. There are millions of organisms in dynamic coexistence with each other and each one of them plays a significant role in the ecosystem. Ecology, thus, has broad objectives and provides a scientific basis for the aims of environmentalism, as well as for evaluating its goals and policies. Ecology does not dictate what is 'right' or 'wrong' , but provides knowledge about the quantification of biodiversity and population dynamics. The objective of ecology is to understand the dynamics of our surroundings and to take

proper measures to conserve it if and when required. However, the main objective of ecology is to study the following:

. The local and geographical distribution and abundance of organisms

. The inter-relationship among organisms in population and communities

. The structural adaptations and functional adjustments of organisms to their

physical environment

. The behaviour of organisms under natural conditions

. The biological productivity of nature and its relationship with mankind

. Temporal changes in the occurrence, abundance and activities of organisms . Conservation and management of natural resources and pollution

Classification of ecology

Ecology is a broad discipline comprising of many sub-disciplines. A common, broad classification, going from the lowest to the highest complexity, where complexity can be defmed as the number of entities and processes in the system under study is as follows:

. Physiological ecology (eco-physiology) and behavioural ecology: It

examines adaptations of an individual to his environment.

. Population ecology (or autoecology): It studies the dynamics of population

of a single species.

. Community ecology (or synecology): It deals with the interactions between

species within an ecological community.

. Ecosystem ecology: It studies the flows of energy and matter through the

biotic and abiotic components of ecosystems.

. Landscape ecology: It examines the processes occurring in multiple

ecosystems or very large geographic areas and studies the relationship between

the processes.

Ecology, however, can also be sub-divided into many other branches, such as

animal ecology, plant ecology, insect ecology, desert ecology, pedology, palaeoecology, ethology, space ecology.

1.3.1 Ecological Balance

Ecological balance or stability ecosystem of the implies a balance between the production and consumption of each component in the ecosystem. According to T.D. Brock, 'Steady state condition in natural ecosystem is a time independent condition in which production and consumption of each constituent in the system is exactly balanced, the concentration of all constituents within the system remains constant, even though there occurs a continual change.'

There are a number of theories, mechanisms and models to explain the stability

Of the ecosystem. The important ones are as follows:

(i) Theory of diversity or stability: If there is diversity of food webs, it.

will lead to an increase in number of links in the food web and if community

succession operates in an ecosystem, the stability will increase.

(ii) Homeostatic mechanism: Inbuilt, self-regulating mechanism is known as homeostatic mechanism. If within an ecosystem the population of

species increases significantly, the result will be scarcity of food, leading to competition for food. Most species will die of starvation and the species population will be brought back to its original value and the stability will be restored.

(iii) Models: The equilibrium, as well as non-equilibrium model can explain stability. Thus, if the ecosystem is disturbed by external factors, it may quickly return to its original state by some adjustments, restoring the stability. However, if it does not return to its original state, the disordered arrangement might lead to cross-relationships and make the system stable.

1.3.2 Issues Affecting Ecological Equilibrium

Ecological factors

In an ecosystem, a living organism is influenced by a large number of environmental factors. These environmental factors are known as ecological factors or eco-factors.

These factors may be biotic (living) or abiotic (non-living). All the environmental factors bring marked distributional, structural and functional changes in orgmri.sms. To live, grow and carry out all its activities, an organism requires a harmonious relationship with its immediate environment. The differences in vegetation of a desert and a rain forest, fish in sweet water and saline water, animals in tropical countries and cold countries, clearly indicate the role of environmental factors in the distribution and survival of organisms in different eco-systems.

The organisms subjected to diurnal, seasonal, annual and cyclic relations of the environment, develop strategies to cope with these changes for their survival. Only those which are able to cope with the conditions, remain and those who cannot, become extinct.

The ecological factors can be classified into the following:

1. Climatic factors: (i) light (ii) temperature (iii) nature (iv) rainfall (v) wind (vi) humidity (vii) atmospheric gases (viii) pH. A variation in these factors affects the distribution and lifestyle of organisms.

2. Topographic factors: (i) altitude (ii) slope and direction of mountain chain

and valleys.

3. Edaphic factors: Structure, formation and characteristics of different types of

soils.

4. Biotic factors: Biotic factors are derived from the interactions between different

species of life (intra-specific as well as inter-specific). The different species

mentioned here are plants, micro-organisms and animals.

5. Limiting factors: Denote the amount of substance that is either least abundant

or over abundant in relation to the need of the living organism.

Climatic factors

(i) Light

Light plays a vital role for both plants and animals. Sunlight is the ultimate source of energy for the biological world. Light is highly essential for photosynthesis, plays an important role in respiration and transpiration, regulates hormones in plants thereby modifying the shape and size and influences the growth and development of flowers, fruits, germination and distribution of plants.

As far as animals are concerned, light influences reproduction and metabolism.

(ii) Heat

Like light, heat exerts a profound influence on the physiological and biochemical activities of organisms. Generally, organisms prefer to conduct their activities in a temperature region of 4°C to 45°C. The physiological effects of temperature are the mineral absorption in plants, water intake, growth, germination in plants and distribution, migration, hibernation and reproductive activities in animals. Both plants and animals exhibit morphological, ecological and physiological adaptation to the variation in temperature. The biochemical effects are due to enzymes and hormonal changes and are related to the temperature.

(iii) Water

Water is one of the most important materials necessary for life. All the physiological processes take place in water. The availability of water in an ecosystem affects the distribution, growth and other activities of its organisms.

(iv) Rainfall

Rainfall (precipitation) determines the type of vegetation in any region. Tropical regions support thick evergreen forests as it experiences heavy rainfall throughout the year. Grasslands are found in regions where there is heavy rainfall in summer and low rainfall in winter. Due to changes in vegetation, animals and birds in various regions also differ.

(v) Wind

Wind brings physical, anatomical and physiological changes to plants. Excessive transpiration due to wind leads to desiccation and death of apical mersistems. Thus, the plants become dwarf, contain small leaves and more branches. On the mountains, due to the danger of uprooting, the vegetation is composed of species having prostrate growth, with long underground roots. This is known as growth of rhizome type.

(vi) Humidity

The physiological activities of organisms, like transpiration, absorption of water, etc., are greatly influenced by humidity. Thus, humidity plays an important role in the life of plants and animals.

(vii) Atmospheric gases

Gases like nitrogen, oxygen, carbon dioxide, water vapour and inert gases are essential for sustaining life. However, gases like sulphur dioxide (SO), nitrogen dioxide (NO), hydrogen sulphide (H2S) and smoke particles from the industries have a major influence on the environment and lead to various physiological changes in plants and animals.

(viii) pH

pH can be a deciding factor in aquatic ecosystem, as far as distribution of organisms is concerned. For aquatic animals as well as for organisms on land, the pH should not be too acidic or too alkaline. For every species, there is an optimum pH level at which they can survive. Large scale industrialization and the discharge of effluents into

water bodies or the soil change the pH level to a great extent, endangering the lives of orgasms’.

Topographic factors

The physical geographical factors are known as topographic factors. These factors include altitude, slope and direction of mountain chains and valleys. All these factors

affect the climatic conditions of a place and thereby influence the distribution of

organisms. With rise in altitude, there is progressive fall in temperature and as we go higher, with a decrease in temperature there is greater activity of the wind. A decrease in soil temperature reduces the absorption of water and nutrients by the plants. In higher altitudes, the atmospheric pressure and decreased concentration of oxygen affects animals, particularly mammals. The slope and direction of mountain chains have a pronounced effect on the amount of solar radiation, rainfall, wind velocity, temperature and on the whole, the climate of the area. This, in turn, affects vegetation patterns and thus, the distribution of animals.

Edaphic factors deal with the structure formation and characteristics of different types of soils.

Soil provides mechanical anchorage to plants and holds water and mineral ions for the plants. They provide a basis for the activities of micro-organisms and animals. Soil contains organic and inorganic colloids, electrolytes, organic matter and soil organism. Soil water forms the lifeline of soil organisms, since proper growth of micro-organisms and invertebrate population within the soil occurs in soil containing adequate moisture. Water is a solvent for the organic nutrients as well as minerals and thus, its contents regulate the physiological, morphological and anatomical features of plants.

Air, found in soil pores, contains CO2, °2' and N2 while their quantity differs from soil to soil. Soil air is a very important edaphic factor that determines the types of micro-organisms, soil animals and vegetation that can grow in the soil. Similar to soil water, it also brings about morphological, physiological and anatomical changes in plants and animals.

The temperature of the soil is very important as it affects the growth of microorganisms, plants and animals. The temperature influences growth of the roots, the ability of the roots to absorb nutrients and movement of organisms.

Soil pH and salinity are also important because when the pH of the soil is very high (highly alkaline) grows on the soil no vegetation. Soil organisms like bacteria, fungi, algae and animals like protozoa, nematodes, earthworms modify the structure of the soil, increase soil fertility, and help to form humus. Nitrogen fixing bacteria and blue-green algae fix atmospheric nitrogen and increase soil fertility. Thus, a change in any of the soil constituents will have a tremendous effect on the whole.

Biotic factors

The living components (animals and plants) of the environment are considered as biotic factors. Organisms in the environment interact among themselves and this may be intra-specific (between populations of same organism) or inter-specific (between populations of different species). Some of the interactions are mutually beneficial while some are beneficial to only one species without harming the others or by harming the others. These interactions are very essential for the occurrence of the biotic factors. Based on the nature of the influence, these interactions can be classified as follows:

(i) Symbiosis

In symbiosis, two different species depend upon each other metabolically and thus, are mutually benefitted. The species are known as symbionts. For example, Rhizobium bacteria and leguminous roots are the symbionts. In this case, the bacteria get protective space to live in and derive readymade food from leguminous roots. The leguminous roots, on the other hand, utilize the fixed nitrogen in the bacteria to manufacture proteins.

(ii) Commensalism

In this case, one species is benefited while the other either benefits or remains neutral. The members are called the commensals and this association, is known as commensalism. For example, some algae and fungi join together to form a different life form known as lichens. The algae manufacture food through photosynthesis, which the fungi utilize and in return, the fungi protects the algae from drying up and together both colonize tree barks, rocks, etc.

Some terrestrial insects and marine animals share the nest or burrow of others without causing any damage to it.

(iii) Parasitism

In this case, there are two different species, i.e., one is the parasite and the other, host. In this relationship, it is the parasite that is benefited and the host harmed. The two different species may be two plants or animals; for example, mosquitoes, bedbugs, lice are the parasites which live on hosts like animal and man, harming them.

(iv) Epiphytism

In this case, epiphytes grow on other plants, but do not derive food from them; for . example, Lianas, a woody plant has roots in the ground but takes the support of other plants to climb.

Some carnivorous plants, like Nepenthes, a pitcher plant, grows on other plants but derives food from insects. They have folded leaf lamina, modified into a pitcher-like structure with a lid. Zooplankton enters into the structure through the lid, gets trapped and the soft parts of its body gets digested by the Nepenthes.

(v) Competition

Organisms survive on some materials and if these are found inadequate, competition occurs. This competition may be both intra-specific and inter-specific. This leads to the survival or dominance of certain species over others. As all species cannot tolerate same range of temperature, humidity, etc., only those who can, Survive.

Limiting factors

Limiting factors denote the amount of substance that is either least abundant or overabundant in relation to the need of the living organism. Limiting factors may be density dependent, for example, when the food stock is fixed for a given density of population, overpopulation will lead to scarcity of food.

Limiting factor may be density independent, for example, earthquake or tsunami may wipe out an entire population irrespective of whether there are few or many. The density independent limiting factors affecting living organisms may be abiotic factors like climate, soil, wind, temperature, water, etc., or other biotic factors. Some climatic conditions may not be tolerable to certain species and might reduce their population, or in extreme cases, make them extinct. If the soil does not have proper amount 01 nutrients, air and moisture, the plants will not prepare balanced and sufficient amount of food to support animal life, reducing their population. Biotic factors are the most important limiting factors that influence the growth and distribution of plants and animals.

Laws of limiting factors

To explain the effect of different limiting factors on living organisms, number of laws and principles have been proposed by different scientists. They are as follows:

1. Liebig's Law of Minimum: An organism requires minimum quantity of a particular nutrient for its proper growth and if it is depicted below the critical minimum level, the organism will fail to grow or will grow abnormally; for example, if the soil is deficient in anyone nutrient, it will make the other nutrient metabolically inactive and the proper growth of the plant will get restricted.

2. Blackman's Law of Limiting Factor: A biological process is controlled by a number of factors and the deficiency of any of these factors will affect the process on the whole; for example, photosynthesis by plants. Photosynthesis is dependent on the correct amount of water, carbon

dioxide, chlorophyll, intensity of solar radiation and temperature of chloroplast. A deficiency of any of these factors will affect the rate of photosynthesis.

3. Shelford's Law of Tolerance: The law states that, it is not only that the minimum amount of a material can be a limiting factor, but also the excess amount of the same material can be limiting to the growth and development of an organism; for example, all the soil nutrients are equally important for the growth and development of plants, but anything in excess might limit the uptake of the other nutrient, restricting the proper growth.

Every organism, thus, has an ecological minimum and maximum for every factor and the range between two limits is known as limit or zone of tolerance. Thus, every environmental factor has two zones:

(i) Zone of tolerance

(ii) (ii) Zone of intolerance

(i) Zone of tolerance: This zone is favourable for the growth and development of all organisms. Zone of tolerance can be sub-divided into the following (see Figure 1.1):

(a) Optimum zone: It is the most favourable zone for the growth and development

of an organism.

(b) Critical minimum zone: It is the lowest minimum limit below which growth

and development of the organism ceases.

(c) Critical maximum zone: It is the highest maximum limit above which growth

and development of the organism ceases.

(ii) Zone of intolerance: Tolerance with respect to various factors differs from species to species. Organisms that have a wide range of tolerance for all factors have a better chance of survival, and hence, are widely distributed.

Fig. 1.1 Range of Tolerance

Ecological instability

When an ecosystem is unable to adjust to the environmental changes, it is said to be unstable. The instability occurs due to a number of natural and anthropogenic activities such as destruction of natural vegetation and animal species, partly or completely or by replacing them by other vegetations and animals, introduction of toxic substances like insecticides and pesticides and toxic gases like S02' N02, etc.

1.4

POPULATION GROWTH

The environmental problems we are facing today are multidisciplinary in nature and mainly arise due to population explosion and overexploitation of natural resources. The world population is increasing rapidly and if the present trend continues, it may cross 8 billion in 2025 and by 2100 it may reach 15 billion Population growth mainly contributes to all the world problems. With an increase in population size as well as population density, there is a great impact on the natural resources. However, it is not only population size and density, but also the technological development as well as the availability of resources that contribute to the impact on a country's natural resources. The highly developed countries, no! only due to less population size and density but due to more available resourced and developed technology, consume larger amount of resources than the people 01 third world countries like India, Pakistan, Bangladesh, etc. Therefore, although population control cannot completely eliminate environment related problems, if can reduce the rate of environmental degradation. The population explosion in Indi! is severe. From 1950 to 1992 the population has gone up from 360 million to 88~ million and is expected to reach approximately 1,400 million by the year 2025, India not only has the second highest population in the world, but the population density is also quite high with 325 persons per square kilometer In the rest of the world, it is 42 persons per square kilometer. China although has the highest population with 20 per cent more compared to India, it has an area thrice than that of our country. Similarly, for other developed countries, there is less population but more area. Table 1.1 illustrates population growth rates of some countries.

Table 1.1 Population Growth Rates for Some Countries

Country	Population	Birth per	Death per	Infant	Rate of
	in million	1000	1000	mortality	natural
	(1998)	individuals	individuals	rate	increase
				(death per	(annual per cen!
				1000 live
				births)
China	1240	17	7	31	1.0
India	990	27	9	72	2,0
USA	270	15	9	7	0.6
Russia	150	9	14	17	- 0,)
Germany	83	10	10	5	- 0.1

There is a significant relationship between the education of women and fertility as well as superstition, religious fanatism which leads to population explosion. in India, education for the female child is very poor and at the same time people believe

in having more children to increase their earnings. The desire to have sons instead of daughters has also contributed significantly to an increase in the population.

Family welfare programmes by the government can control population growth. The legal age for marriage should be raised and measures to control birth rate should lie popularized.

Various contraceptive methods should be applied so that it is accepted by all sections of the society. Abortion can also be an alternative.

The overexploitation of resources due to population explosion and human greed has led to: (i) deforestation (ii) depletion and contamination of surface and ground water (iii) depletion of non-renewable fuels (iv) depletion of non-renewable minerals (v) depletion of biodiversity.

The present environmental crisis lie in the paradigms of scientific materialism and economic determinism, which is yet to learn the limits imposed by eco-systems on economic activity. The economics, therefore, should only expand within the eco

systems which have limited regenerative capacities. Sustainable development can be the only solution and it must follow these strategies:

. Control population explosion

. Conserve all kinds of natural resources to maintain biodiversity

. Use renewable resources and reduce the use of non-renewable resources

1.5

NATURAL RESOURCES AND THEIR DEPLETION

According to Ramade (1984), a natural resource is defined as a form of energy and! or matter which is essential for the functioning of organisms, populations and ecosystems. In the case of humans, natural resource refers to any form of energy or matter essential for the fulfilment of physiological, socio-economic and cultural needs, both at the individual level and that of the community.

Examples of natural resources are water, air, soil, minerals, coal, forests, crops and wildlife. The basic ecological variables-energy, space, time and diversity are sometimes together called natural resources. These natural resources maintain the ecological balance among themselves. Man is the only organism who has disrupted this delicate balance.

1.5.1 Classification of Natural Resources

There are many different classifications of natural resources. 1. Odum's classification

According to Odum (1971), natural resources can be divided into two categories, viz., renewable and non-renewable resources.

(i) Renewable resources: Resources that can be replenished through rapid natural cycles are known as renewable resources. These resources are able to increase their abundance through reproduction and utilization of simple substances. Examples of renewable resources are plants (crops and forests), and animals who are able to reproduce and maintain life cycles. Some examples of renewable

resources which do not have life cycle, but can be recycled are wood and wood products, pulp products, natural rubber, fibers (e.g., cotton, jute, animal wool, silk and synthetic fibres) and leather. In addition to these resources, water and soil are also classified as renewable resources. Water is no longer referred to as a renewable resource. This is because of its loss in natural replenishment due to global warming, increased deforestation and resulting disturbances in the hydrological cycle. Groundwater is depleting at a fast pace, and a time will soon come when its existence will be in jeopardy.

As a special case, solar energy, though having a finite life, is considered as a renewable resource in as much as solar energy stocks are inexhaustible on the human scale.

(ii) Non-renewable resources: The resources that cannot be replenished through natural processes are known as non-renewable resources. These are available in limited amounts, which cannot be increased. These resources include fossil fuels (petrol, coal, etc.), metals (iron, copper, gold, silver, lead, zinc, etc.), minerals and salts (carbonates, phosphates, nitrates, etc.). Once anon-renewable resource is consumed, it is gone forever. Then we have to find a substitute for it or do without it.

Non-renewable resources can further be divided into two categories-recyclable and non-recyclable.

(a) Recyclable: These are non-renewable resources which can be collected after they are used and can be recycled. These are mainly the non-energy mineral resources which occur in the earth's crust (e.g., ores of aluminium, copper, mercury, etc.) and deposits of fertilizer nutrients (e.g., phosphate stock and potassium and minerals used in their natural state (asbestos, clay, mica, etc.)

(b) Non-recyclable: These are non-renewable resources which cannot be recycled in any way. Examples of these are fossil fuels and uranium, which provide 90 per cent of our energy requirements.

2. Biotic and abiotic resources

Some authors prefer to classify resources into biotic and abiotic resources.

(i) Biotic resources: These are living resources (e.g., forest, agriculture, fish and

wild life) that are able to reproduce or replace them.

(ii) Abiotic resources: These are non-living resources (e.g. petrol, land, minerals,

etc.) that are not able to replace themselves or do so at such a slow rate that

they are not useful to consider them in terms of the human life times.

3. Inexhaustible and exhaustible resources

Natural resources can also be classified as: inexhaustible and exhaustible resources.

(i) Inexhaustible resources: Resources which are not changed or exhausted by man's activities and are abundantly available are said to be inexhaustible. Examples of such resources are solar energy, atomic energy, wind power, power from tides, etc. Most of the renewable resources are classified as inexhaustible. But if not maintained properly, they become extinct; for example, groundwater is renewable only if water continues to percolate in the soil at a rate at which it is removed.

(ii) Exhaustible resources: These resources are limited in nature and they are non-maintainable, e.g., coal, petrol and some minerals. Hence, they come under the non-renewable category.

Even our renewable resources can become non-renewable if we exploit them

to such extent that their rate of consumption exceeds their rate of regeneration. For example, if a species is exploited so much that its population size declines below the threshold level, then it is not able to sustain itself and gradually the species becomes endangered or extinct.

It is very important to protect and conserve our natural resources and use them in a judicious manner, so that we do not exhaust them. It does not mean that we should stop using most of the natural resources. Rather, we should use the resources in such a way that we always save enough of them for our future generations.

The following are some of the major natural resources: 1. Forest resources

2. Water resources

3. Mineral resources 4. Food resources

5. Energy resources 6. Land resources

1.5.2 Forest Resources

Forest resource is the dense growth of trees, together with other plants, covering a large area of land. Forests are one of the most common natural resources found on earth. Covering earth like a green blanket, these forests not only produce innumerable material goods, but also provide several environmental services which are essential for life. About one-third of the world's land area is forested, which includes closed as

well as open forests. Former USSR accounts for about one-fifth of the world's forests,

Brazil [or about one-seventh and Canada and USA has 6-7 per cent each. But, it is a

I matter of concern that almost everywhere the cover of the natural forests has declined

lover the years. The greatest loss occurred in tropical Asia, where one-third of the

I forest resources have been destroyed.

. Uses of forests

I Commercial uses: Forests provide us a large number of commercial goods which

include timber, firewood, pulpwood, food items, gums, resins, non-edible oils, rubber,

fibres, lac, bamboo canes, fodder, medicine, drugs and many more items, the total of which is estimated to cost more than US $300 billion per year.

Half of the timber that is cut each year is used as fuel for heating and cooking.

One-third of the wood harvest is used for building materials as lumber, plywood and hardwood, particle board and chipboard. One-sixth of the wood harvest is converted into pulp and used for paper industry. Many forest lands are used for mining, agriculture, grazing, and recreation and for development of dams.

Ecological uses: While a typical tree produces commercial goods worth about US $590, it provides environmental services worth nearly US $196 to US $250.

The ecological services provided by forests may be summed up as follows: 1. Production of oxygen: Trees produce oxygen by photosynthesis which is

so vital for life on this earth. They are rightly called earth's lungs.

2. Reducing global warming: The main greenhouse gas carbon dioxide (CO) is absorbed by the forests as a raw material for photosynthesis. Thus, forest canopy acts as a sink for CO2, thereby reducing the problem of global warming caused by greenhouse gases such as CO2,

3. Wild life habitat: Forests are the homes of millions of wild animals and

plants. About 7 million species are found in the tropical forests alone.

4. Regulation of hydrological cycle: Forested watersheds act like giant sponges, absorbing the rainfall, slowing down the run-off and slowly releasing the water for recharging of the springs. About 50-80 per cent of the moisture

in the air above tropical forests comes from their transpiration, which helps. in bringing rains.

5. Soil conservation: Forests bind the soil particles tightly in their roots and

prevent soil erosion. They also act as windbreaks.

6. Pollution moderators: Forests can absorb many toxic gases and can help in

keeping the air pure and clean. They also absorb noise and thus, help in

preventing air and noise pollution.

Overexploitation of forests

Since time immemorial, humans have depended heavily on forests for food, medicine, shelter, wood and fuel. With growing civilizations, the demands for raw materials like timber, pulp, minerals and fuel wood shooted up resulting in large-scale logging, mining, road-building and clearing of forests. Our forests contribute substantially to the national economy. The international timber trade alone is worth over US $40 billion per year. Excessive use of fuel wood and charcoal, expansion of urban, agricultural and industrial areas and overgrazing have together led to overexploitation of our forests leading to their rapid degradation.

Deforestation

The total forest area of the world in 1995 was estimated to be 7000 million hectares, which was reduced to 2890 million hectares in 1995 which further fell down to just 2300 million hectares by 2000. The rate of deforestation is relatively less in temperate countries, but it is alarmingly high in tropical countries, where it is as high as 40-50 percent; at the present rate, it is estimated that in the next sixty years we would lose more than 90 per cent of our tropical forests.

The forested area in India seems to have stabilized since 1982 with about 0.04 per cent decline in deforestation annually between 1982-90. In 1993, Food and Agricultural Organization (FAO) estimated that about 1.44 m hectares of land were brought under afforestation during this period leading to stabilization. As per FAO estimates, the deforestation rate per unit population in India is the lowest among the major tropical countries, despite the fact that we have a huge population size and very low per capita forest area (0.075 ha per capita). However, we are still far behind the target of achieving 33 per cent forest cover, as per our National Forest Policy, as we still have only 19.27 per cent of our land area (63.38 m ha) covered by forests based on satellite data (Ministry of Environment and Forests, MoEF, 1998).

Major causes of deforestation

1. Shifting cultivation: There are an estimated 300 million people living as shifting cultivators who practice slash and burn agriculture. In India, we have this practice in the north-east and to some extent in Andhra Pradesh, Bihar and MP which contribute to nearly half of the forest clearing annually.

2. Fuel requirements: Increasing demands for fuel wood by the growing population in India alone has shooted up to 300--500 million tonnes in 2001 as compared to just 65 million tonnes during independence, thereby increasing the pressure on forests.

3. Raw materials for industrial use: Wood for making boxes, furniture, railwaysleepers, plywood, match boxes, pulp for paper industry, etc., have exerted tremendous pressure on forests. Plywood is in great demand for packing tea, while fir tree wood is exploited greatly for packing apples.

4. Development projects: Massive destruction of forests occur for various development projects like hydroelectric projects, big dams, road construction and mining.

5. Growing food needs: In developing countries, this is the main reason for deforestation. To meet the demands of a rapidly growing population, agricultural lands and settlements are created permanently by clearing forests.

6. Overgrazing: The poor in the tropics mainly rely on wood as a source of fuel leading to loss of tree cover and the cleared lands are turned into grazing lands. Overgrazing by cattle leads to further degradation of these lands.

Major consequences of deforestation

Deforestation has far-reaching consequences, which may be detailed as follows:

1. It threatens the existence of many wild life species due to destruction of their

natural habitat.

2. Biodiversity is lost and genetic diversity is eroded.

3. Hydrological cycle gets affected, thereby influencing rainfall.

4. Problems of an increase in and soil infertility soil erosion.

5. Deforestation often leads to landslides in hilly areas

6. The effects of global warming may aggravate due to lack of oxygen generation

and an increase in the level of carbon dioxide in the air.

Major activities in forests

. Timber extraction: Logging for valuable timber such as teak and mahogany not only involves a few large trees per hectare, but about a dozen more trees since they are strongly interlocked with each other by vines, etc., and construction of roads in forests causes further damage to them.

. Mining: Mining operations for extracting minerals and fossil fuels like coal often involve vast forest areas. Mining from shallow deposits is done by surface mining, while that from deep deposits is done by sub-surface mining. More than 80,000 ha of land in this country is presently under the stress of mining activities. Mining and its associated activities require removal of vegetation along with the underlying soil mantle and overlying rock masses. This results in defacing the topography and destruction of the landscape in the area.

Self-. Matt

Large-scale deforestation has been reported in Mussorie and Dehradun valley due to indiscriminating mining of various minerals over a length of about 40 kIn. The forested area has declined at an average rate of33 per cent and the increase in non-forest area due to mining activities has resulted in relatively unstable zones, leading to landslides.

Indiscriminate mining in forests of Goa since 1961 has destroyed more than 50,000 ha of forest land. Coal mining in Jharia, Raniganj and Singrauli areas have caused extensive deforestation in Jharkhand. Mining of magnesite and soap-stones have destroyed 14 ha of forest in hill slopes of Khirakot, Kosi valley, Almora. Mining of radioactive minerals in Kerala, Tamilnadu and Karnataka are posing similar threats of deforestation. The rich forests of Western Ghats are also facing the same threat due to mining projects for excavation of copper, chromite, bauxite and magnetite.

. Mining engineering: Mining engineering is a field that involves many of the other engineering disciplines as applied to extracting and processing minerals from a naturally occurring environment.

The need for mineral extraction and production is an essential activity of any

technically proficient society. As minerals are produced from within a naturally occurring environment, disturbance of the environment as a result of mineral production is a given. Modem mining engineers must, therefore, be concerned not only with the production and processing of mineral commodities, but also with the mitigation of damage or changes to an environment as a result of that production and processing.

The two primary types of mines are underground mines and open-pit mines. Minerals that exist relatively deep underground (for example, some coal seams, gold and some metalliferous ores) are generally recovered using underground mining methods. Minerals like iron ore, shallow coal seams and bauxite are usually recovered from the surface by open pit mining.

Dams and their effects on forests and people

Big dams and river valley projects have multi-purpose uses and Pandit Jawaharlal Nehru used to refer to these dams and valley projects as 'temples of modern India'. However, these dams are also responsible for the destruction of vast areas of forests. India has more than 1550 large dams, the maximum being in the state of Maharashtra (more than 600), followed by Gujarat (more than 250) and Madhya Pradesh (130). The highest one is Tehri dam, on river Bhagirathi in Uttaranchal and the largest in terms of capacity is Bhakra dam on river Satluj in Himachal Pradesh.

Big dams have been in sharp focus of various environmental groups all over the world, because of several ecological problems including deforestation and socioeconomic problems related to tribal or native people associated with them.

The Silent Valley Hydro-Electric Project was one of the first such projects situated in the tropical rain forest area of West em Ghats, which attracted much concern of the people.

The crusade against the ecological damage and deforestation caused due to Tehri dam was led by Shri Sunderlal Bahaguna, the leader of Chipko Movement. The cause of Sardar Sarovar Dam related issues taken up by the environmental activitist Medha Patkar, joined by Arundhati Roy and Baba Amte.

For building big dams, large-scale devastation of forests takes place which breaks the natural ecological balance of the region. Floods, droughts and landslides occur recurrently in such areas.

Forests are the repositories of invaluable gifts of nature in the form of biodiversity and by destroying them (particularly, the tropical rain forests), we are going to lose these species even before knowing them. These species could have marvelous

economic or medicinal value and deforestation results in loss of this storehouse of species which have evolved over millions of years.

1.5.3 Water Resources

Water is an indispensable natural resource on this earth on which all life depends. About 97 per cent of the earth's surface is covered by water and most of the animals and plants have 60-65 per cent water in their body. Water is characterized by certain unique features which make it a marvelous resource. These are:

. Water exists as a liquid over a wide range of temperature i.e., from 0 to 100°C. . It has the highest specific heat, due to which it warms up and cools down very

slowly without causing fluctuations in temperature, thereby protecting the aquatic life.

. It has high latent heat of vapourization. Hence, it takes huge amount of energy

for getting vapourized. That is why it produces a cooling effect as it evaporates.

. It is an excellent solvent for several nutrients. Thus, it can serve as a very good carrier of nutrients, including oxygen, which are essential for life. It can also easily dissolve various pollutants and become a carrier of pathogenic microorganIsms.

. Due to high surface tension and cohesion, it can easily rise through great heights,

through tree trunks even in the tallest of the trees like Sequoia.

. It has an anamolous expansion behaviour, i.e., as it freezes it expands instead of contracting and thus becomes lighter. It is because of this property that even in extreme cold, lakes freeze only on the surface. Being lighter, ice keeps floating, whereas the water underneath the ice remains at a higher temperature and therefore, can sustain aquatic organisms even in extreme cold.

The water we use keeps on cycling endlessly through the environment. This is

known as the hydrological cycle. We have enormous resources of water on earth amounting to 1404 million km3. The water from various moist surfaces evaporates and again falls on the earth in the form of rain or snow and passes through living organisms and ultimately returns to the ocean. Every year, about 1.4 inch thick layer of water evaporates from the oceans, more than 90 per cent of which returns to the oceans through the hydrological cycle. Solar energy drives the water cycle by evaporating it from various bodies, which subsequently return through rainfall or snow. Plants too playa very vital role by absorbing the groundwater from the soil and releasing it into the atmosphere by the process of transpiration.

Global distribution of water resources is quite uneven depending upon several geographic factors. Tropical rain forest areas receive maximum rainfall, while the major world deserts occur in zones of dry, descending air (20-40° Nand S) and receive very little rainfall.

F or building big dams, large-scale devastation of forests takes place which breaks the natural ecological balance of the region. Floods, droughts and landslides occur recurrently in such areas.

economic or medicinal value and deforestation results in loss of this storehouse of species which have evolved over millions of years.

1.5.3 Water Resources

. Water exists as a liquid over a wide range of temperature i.e., from 0 to 100°C. . It has the highest specific heat, due to which it warms up and cools down very

slowly without causing fluctuations in temperature, thereby protecting the aquatic life.

. It has high latent heat ofvapourization. Hence, it takes huge amount of energy

for getting vapourized. That is why it produces a cooling effect as it evaporates.

. Due to high surface tension and cohesion, it can easily rise through great heights,

through tree trunks even in the tallest of the trees like Sequoia.

The water we use keeps on cycling endlessly through the environment. This is

oceans through the hydrological cycle. Solar energy drives the water cycle by evaporating it from various bodies, which subsequently return through rainfall or snow. Plants too playa very vital role by absorbing the groundwater from the soil and releasing it into the atmosphere by the process of transpiration.

Due to its unique properties, water has multiple uses for all living organisms. Water is absolutely essential for life. Most of the life processes take place in water contained in the body. Intake of nutrients, their distribution in the body, regulation of temperature, and removal of wastes are all mediated through water. Water is used by humans in the two following ways:

1. Water withdrawal: This involves taking water from groundwater or surface

water resource.

2. Water consumption: Here, the water which is taken up is not returned for

reuse.

Water: A precious natural resource

Although water is still abundant on earth, it is very precious. Out of the total water reserves of the world, about 97 per cent is salt water (marine) and only 3 per cent is fresh water. Even this small fraction of fresh water is not available to us completely; most of it is locked up in the polar ice caps and just 0.003 per cent is readily available to us in the form of groundwater and surface water.

Overuse of groundwater for drinking, irrigation and domestic purposes has resulted in rapid depletion of groundwater in various regions leading to lowering of water table and drying of wells. Pollution of many of the groundwater aquifers has resulted in making these wells unfit for consumption.

Rivers and streams have long been used for discharging of wastes. Most of the civilizations have grown and flourished on the banks of rivers, but unfortunately, growth in turn has been responsible for pollution of the rivers.

. Groundwater: About 9.86 per cent of the total fresh water resources is in the form of groundwater and it is about 35-50 times that of surface water supplies. Effects of groundwater usage: (i) Subsidence; (ii) Lowering of water table and (iii) Waterlogging

. Surface water: When the water formed through precipitation (rainfall, snow) does not percolate down into the ground or does not return to the atmosphere through evaporation or transpiration loss, it assumes the form of streams, lakes, ponds, wetlands or artificial reservoirs, known as surface water. The surface water is largely used for irrigation, industrial use, public water supply, navigation, etc. As you know, a country's economy is largely dependent upon its rivers.

The problems arising out of water resources are floods, droughts. Apart from these, there are conflicts over water. Indispensability of water and its unequal distribution has often led to inter-state or international disputes. Issues related to sharing of river water have been largely affecting our farmers and also shaking our governments. Some major water conflicts are: (i) Water conflict in the Middle Eastcountries involved are Sudan, Egypt, Turkey-it also affects countries who are water starved, viz., Saudi Arabia, Kuwait, Syria, Israel and Jordan; (ii) The Indus Water Treaty-there is dispute between India and Pakistan; (iii) The Cauvery water dispute

involves two major southern states of India, Tamilnadu and Karnataka. Similarly, the Satluj-Yamuna Link canal dispute also involves two northern states, Punjab and Haryana. Affected states include UP, Rajasthan as well as Delhi.

In traditional water management, innovative arrangements ensure equitable distribution of water. The gram sabhas approve these plans publicly. While water disputes between states and nations often resume battle-like situations, our traditional water managers in villages prove to be quite effective.

Big dams: Benefits and problems

Benefits

River valley projects with big dams have usually been considered to playa key role in the developmental process due to their multiple uses. India has the distinction of

having the largest number of river valley projects. These dams are often regarded as a symbol of national development. Such projects result in providing employment, raising the standard of living and improving the quality of life. Such projects have tremendous potential for economic upliftment and growth. It can check floods and famines, generate electricity and reduce water and power shortages, provide irrigation water to lower areas, provide drinking water in remote areas and bring about overall development of the region.

Environmental problems

The environmental impact of big dams are also too many, due to which, big dams become an issue of controversy quite often. The impacts can be at the upstream as well as the downstream levels.

Upstream problems: These are as follows:

. Displacement of tribal people

. Loss of forests, flora and fauna

. Changes in fisheries and the spawning grounds

. Siltation and sedimentation of reservoirs

. Loss of non-forest land

. Stagnation and waterlogging near reservoir

. Breeding of vectors and spread of vector-borne diseases . Reservoir Induced Seismicity (RIS) causing earthquakes . Growth of aquatic weeds

. Microclimatic changes

Downstream impacts: These are as follows:

. Waterlogging and salinity due to overirrigation . Micro-climatic changes

. Reduced water flow and silt deposition in rivers . Flash floods

. Salt water intrusion at river mouths

. Loss of land fertility along the river since the sediments carrying nutrients get.

deposited in the reservoir

. Outbreak of vector-borne diseases like malaria

Thus, dams are built to serve the society with multiple uses, but it has several serious side-effects. That it why now there is a shift towards construction of small dams or min-hydel projects.

1.5.4 Mineral Resources

Minerals are naturally occurring, inorganic, crystalline solids having definite chemical composition and characteristic physical properties. There are thousands of minerals occurring in different parts ofthe world. However, most of the rocks we see everyday are just composed of few common minerals like quartz, feldspar and biotite. These minerals, in turn, are composed of some elements like silicon, oxygen and iron.

Minerals are generally used for development of industrial plants, generation of energy, construction, equipment and armament for defence, transportation, medical system, communication, jewellery-gold, silver, etc.

Environmental impacts of mineral extraction are devegetation and defacing of landscape, subsidence of land, groundwater contamination, surface water pollution, air pollution, occupational health hazards, etc.

Remedial measures include adoption of eco-friendly technology, microbial leaching technique, restoration of mined areas by re-vegetating them with appropriate plant species, stabilization of the mined lands and gradual restoration of flora.

1.5.5 Food Resources

There are thousands of edible plants and animals the world over, yet only about three dozen types constitute the major food of humans. The main food resources include wheat, rice, maize, potato, barley and oats and about twenty or so common fruits and vegetables, milk, meat, fish and seafood.

World food problems

Every year food problem is killing as many people as were hlled by the atomic bomb dropped on Hiroshima during World War II. This shows thallhere is a drastic need to increase food production, equitably distribute it and also to control population growth. Although India is the third largest producer of staple crops, an estimated 300 million Indians are still undernourished. India has only half as much land as USA, but it has nearly three times population to feed. Our food problems are directly related to population. Due to overgrazing, the agricultural land gets affected. The manifestations of the problem might be through as follows:

. Land degradation

. Soil erosion

. Loss of useful species

Agriculture also makes an impact on the usage of land as follows:

. Deforestation

. Soil erosion

. Depletion of nutrients

The impact of modem agriculture is as follows:

. Impact related to High Yielding Varieties (HYV).

. Fertilizer-related problems include micronutrient imbalance, nitrite pollution

and eutrophication.

. Pesticide-related problems include creating resistance in pests and producing

new pests, death of non-target organisms, biological magnification.

. Some other problems include waterlogging and increased salinity.

STATEMENT BY THE ADVISORY GROUP ON NUTRITION ON THE WORLD FOOD PROBLEM, HUNGER AND MALNUTRITION

In the two decades since the World Food Conference of 1974, the questions of how much food the world grows and how that food is distributed have rightly remained at the centre of

international debate and concern. For most of that time, the main emphasis has been on access to food and on distribution, rather than on supply. We believe that emphasis was correct. It directed discussion to questions of food entitlement, household and individual food security and matters related to the quality and safety of food for human consumption. These concerns have been prominent in international statements, most recently the International Conference on Nutrition in 1992. International policy commitments have in turn been associated with modest increases in resource flows to nutrition and related fields, not just to save lives in famines, but also to help achieve food and nutrition goals in the longer term.

Recently, an alternative set of concerns has re-emerged, which has begun to direct attention back to food supply. Rising population, increasing urbanization, doubts about the sustainability of intensive farming and irrigation systems and an apparent slow-down in the rate of increase of yields of the major food staples, are factors which, have led some observers to argue for a higher priority to be given to agricultural research and to investments designed to increase agricultural productivity and production. The case is said to be strengthened by structural changes in the world economy, including the changes in Eastern Europe and the former Soviet Union and the effect of the GATT agreement on world food trade.

Our continuing concern about under nutrition and household food security leads us to conclude that agricultural research and investment will have their greatest impact on reducing hunger if they are planned specifically to take account of the changing geographical and

socio-economic characteristics of hunger in the world, and of poor people's perceptions of their malnutrition-related problems. In the immediate future, this will mean increased attention to the production potential of poor people living in resource-poor areas, to the promotion of secure and sustainable livelihoods in Africa, to the needs of female-headed households and semi-urban populations and to measures which will mitigate the appalling effects of severe drought and conflict on food supply, food prices and the command over food by poor people.

Because it is imperative to assure a sustainable and sufficient world food supply, it is necessary to keep under review investments in agricultural research, agriculture and other components affecting supply. We believe that increased investments in these areas are entirely in concert with the massive programmes of action required to achieve the goals set by the International Conference on Nutrition. At the same time, and in a world where aid resources are increasingly scarce, the additional resources required to address issues related to world food supply should not be sought at the expense of those needed to strengthen the effective demand of the deprived for food, health and household care. In our analysis of the world food problem, household access to food remains one of the most urgent food problems for the foreseeable future.

Source: Report on the Twenty-First Session of the Sub-Committee on Nutrition, UNICEF, New York, 7-1 I March 1994.

1.5.6 Energy Resources

Energy consumption of a nation is usually considered as an index of its development. This is because almost all the development activities are directly or indirectly dependent

upon energy. There are wide disparities in per capita energy use between the developed and the developing nations.

The original form of energy based technology probably was fife, which produced heat and the early man used it for cooking and heating purposes. Wind and hydropower has also been used. Invention of stearn engines replaced the burning of wood by coal and coal was further replaced by oil.

Energy resources are primarily divided into two categories, viz. renewable and non-renewable resources. Renewable energy resources must be preferred over the non-renewable resources. This will seek to end the energy crisis which the world is facing today. It is inevitable truth that now there is an urgent need of thinking in terms of alternative sources of energy, which are also termed as non-conventional energy sources. These include solar energy, wind energy, hydropower, tidal energy, ocean thennal energy, geothennal energy, biomass, biogas and biofuels.

The non-renewable energy sources include coal, petroleum, natural gas and nuclear energy.

1.5.7 Land Resources

Land as a resource

Land is a finite and valuable resource upon which we depend for our food, fibre and fuel wood-the basic amenities of life. Soil is also a valuable resource.

Land degradation

Because of increase in population, the demands for arable land for producing food and fuel wood is also increasing. Hence, there is more and more pressure on the limited land resources which are being depleted due to overexploitation. Soil erosion, waterlogging, salinization and contamination of the soil with industrial wastes like fly ash, press mud or heavy metals all cause degradation of land.

. Soil erosion: Soil erosion means wearing away of soil. It is defined as the movement of soil components, especially surface-litter and top soil from one place to another. It results in the loss of fertility.

It is basically of two types, viz, normal erosion or geological erosion and accelerated erosion. The agents that cause such erosions are climatic agents and biotic agents. Wind is also responsible for land erosion through saltation, suspension and surface creep.

In order to prevent soil erosion and conserve the soil, the following conservation practices are employed:

· Conservational till fanning

· Contour fanning

· Terracing

· Strip cropping

· Alley cropping

· Wind breaks or shelterbelts

· 0Waterlogging

. Landslides: Various anthropogenic activities such as hydroelectric projects, large darns, reservoirs, construction of roads and railway lines, construction of buildings and mining are responsible for clearing of large forested areas.

. Desertification: It is a process whereby the productive potential of arid or semiarid lands falls by ten per cent or more. Desertification is characterized by devegetation and loss of vegetal cover, depletion of groundwater, salinization and severe soil erosion. The causes of desertification are deforestation, overgrazing and mining and quarrying.

1.5.8 Equitable Use of Resources for Sustainable Lifestyle

There is a big division in the world in the use of resources, viz., north and south, more developed countries (MDCs) and less developed countries (LDCs), haves and havenots.

It is observed that MDCs have only 22 per cent of world's population, but they use 88 per cent of natural resources, 73 per cent of energy and command 85 per cent of income; in turn, they contribute a big proportion to its pollution. On the other hand, LDCs have very low or moderate industrial growth and have 78 per cent of the world's population. They use only 12 per cent of natural resources, 27 per cent of energy and have only 15 per cent of global income. The rich have gone richer and the poor have become poorer. There is a huge gap between them. This is not sustainable growth.

The solution to this problem is to have better equitable distribution of resources and wealth. A global consensus has to be reached for balanced distribution. There are two major causes of unsustainability. These are:

I. Overpopulation in poor countries

2. Overconsumption of resources by rich countries

The rich countries will have to lower their consumption levels and the minimum needs of the poor must be satisfied by providing them resources. The need of the hour is fairer sharing of resources between the rich and poor, which will bring about sustainable development ~or all.

Within the concept of sustainable development, industrial ecology plays a

significant role in order to create a balance between industrial development and preservation of natural resources. It refers to the adoption of such industrial processes, technology, equipment and raw material where the products can be recycled after their life cycle is complete or can be put to alternative use or a byproduct can be made out of it. This not only reduces the pressure on raw materials and compensates them for producing afresh, it also reduces the costing impact. Advanced technology also reduces wastage and is more energy efficient.

1.6

INDUSTRIAL AND URBAN POPULATION

It was estimated that by 2008, the world would reach its milestone; more than half its human population-3.3 billion people will be living in urban areas. It is also estimated that by 2030, this population will rise to almost 8 to 8.5 billion, and most of them will be poor. Thus, it is important to make cautious decisions as the future of this growing population and the future of developing countries will depend on the decisions currently made to prepare for this growth.

Over the 20th century, the urban population of the world increased from 220 million to 2.8 billion. The following decades will encounter an unprecedented scale of urban growth in the developing world. It would be specifically noticeable in Asia and Africa as there the urban population will double between the years 2000 and 2030.

This implies that the entire span of history is going to be duplicated in one single generation in the accumulated urban growth of these two regions.

Urbanization means the increase in the urban share of the total population. It is unavoidable; however, it can also be positive. Presently, it is threatening to see the slum growth, social disruption and concentration of poverty in the cities. In spite of the negative effects of urbanization, significant economic growth cannot be achieved without it by any country which is in the industrial age.

Cities also represent the environmental damage caused due to modern civilization; yet policymakers and experts continuously recognize the cities' potential value to long-term sustainability. Cities, apart from creating problems to the environment, also contain the solution to it. Also, the advantages of urbanization dominate the disadvantages; if only the possibilities to exploit it could be learnt.

In 1994, the Programme of Action of the International Conference on Population and Development called on governments to 'respond to the need of all citizens, including urban squatters, for personal safety, basic infrastructure and services, to erifuinate health and social problems. . . .' I Recently, the United Nations Millennium Declaration specified in Target 11 the ambition of achieving' a significant improvement in the lives of at least 100 million slum dwellers'2, which drew attention to the growing significance of urban poverty.

UN-Habitat's Third World Urban Forum, as well as its State of the World's

Cities 2006/7, successfully focused world interest on the deteriorating environmental and social conditions of urban localities.3 The globalization process has also attracted focus to the human cost and to the productive potential of cities. However, the great impact and scale of future urbanization has not entered the mind of the public.

So far, the main focus of attention has been on immediate concerns, problems, like ways of accommodating the poor and improving the conditions of living, employment generation, reducing ecological footprint of cities, improving governance, and ways of administering increasingly complex urban systems.

They are important concerns, but when compared to the problems raised by approaching future growth of the urban population, their intensity lessen. Till now, as the challenges came up, the civil society organizations and policymakers have reacted to them. This is not enough any longer; it is necessary to have a pre-emptive approach if in developing countries urbanization is to help solve environmental as well as social problems, instead of making them devastatingly worse.

Thus, it is important to look beyond the current problems, no matter how urgent,

real and poignant they are. Yet, it is also a call to action.

Mega-cities get most of the attention; however, conditions in smaller urban areas call for even greater consideration. Opposed to the general belief, the major urban population growth is most likely to be in smaller tClwns and cities, where the

possibilities of planning and implementation are very weak. Nevertheless, the process of decentralizing the powers of the government all over the world implies the transfer of more responsibilities on them. As the population in smaller cities increases, their thin planning and managerial capacities will get under a lot of stress. It will be necessary to find new ways to equip them to plan ahead for expansion, to use their resources sustainably and to deliver essential services.

Poor people will make up a large part of future urban growth; this is unavoidable unless timely measures are taken. Rather than migration, the reason behind increase in urban growth is natural increase (lesser death rate and higher birth rate). No matter the reason behind the increase in urban population, it includes a large number of poor people. Choosing to ignore this basic reality will make it impossible either to plan for massive and inevitable city growth or to use urban dynamics to help relieve poverty.

Once the civil society and the policymakers understand and accept the social

and demographic composition of urban growth, some basic approaches and initiatives suggest themselves. These may have an impact on the poor people's fate and on the viability of the cities themselves. Civil society, along with national and urban governments, may take steps which will make a difference for the economic, environmental and social living conditions of a majority of the world's population. This can be done with the help of international organizations.

There are three policy initiatives that are available in this connection. Primarily, respecting the poor people's rights to the city is a minimum prerequisite for an urban future. Mostly, policymakers discourage rural-urban migration as a way of preventing urban growth. They do that by undertaking measures, such as evicting squatters and denying them services. Such attempts of preventing migration are wrong; they violate the rights of the people. They are also counter-productive. There are options that respect human rights that can be undertaken in case the urban growth rates are too high according to the policymakers. Advances in social development, .such as making

education available universally, promoting gender equity and equality and meeting reproductive health needs, are important for their own sake. However, they will also enable women in avoiding unwanted pregnancies and reduce the main factor in the growth of urban populations-natural increase.

Second, cities need a longer-term and broader vision of the use of urban space to promote sustainability and reduce poverty. This includes concern with the needs of

the land of the poor. The basic essentials for a poor family is an adequate piece of land with accessibility to water, power, transport and sewage, on which they can construct their homes and improve their lives. A new and proactive approach is required to provide all this. Planning for such spatial and infrastructure requirements, keeping in mind the multiple roles and needs of a poor woman, will greatly in1prove the welfare of poor families. Such a people-centric development knits together the social fabric and encourages economic growth that includes the poor. Similarly, purposeful management of space in advance of needs is required to protect the environment and managing ecosystem services in future urban expansion requires.

The urban footprint stretches beyond the boundaries of the city. Also, environmental conditions largely affect and influence cities. Proactive policies for sustainability will be important as well in view of climate change and the considerable proportion of urban concentrations at or near sea level.

Third, population institutions and specialists may and must playa key role in supporting social movements, community organizations, governments and the international community to improve the form and nature of future urban expansion, and hence enhance its power to reduce poverty and promote environmental sustainability. At such a time, a concerted international effort necessary for clarifying policy options and providing information and analyses that will support strategies to improve the urban future.

1.7 GLOBAL WARMING

Troposphere, the lower-most layer of the atmosphere, traps heat by natural processes due to the presence of certain gases. This effect is called greenhouse effect, as it is

similar to the warming effect observed in the horticultural greenhouse made of glass. .

The amount of heat trapped in the atmosphere depends mostly upon the concentration of heat trapping or greenhouse gases and the length of time they stay in the atmosphere. The major green house gases are carbon dioxide, ozone, methane, nitrous oxide, and water vapour.

The average global temperature is 15°e. In the absence of greenhouse gases, this temperature would have been 18°e. Therefore, greenhouse effect contributes to a temperature rise to the tune of33°e.

Heat trapped by greenhouse gases in the atmosphere keeps the planet warm enough to allow us and other species to exist. The two predominant greenhouse gases are water vapour that is controlled by the hydrological cycle, and carbon dioxide that is controlled mostly by the global carbon cycle. While the levels of water vapour in the troposphere have relatively remained constant, the levels of carbon dioxide have increased.

Other gases whose levels have increased due to human activities are methane and nitrous oxide. Deforestation has further resulted in elevated levels of carbon dioxide due to non-removal of carbon dioxide by plants through photosynthesis.

Warming or cooling by more than 2°e over the past few decades may prove to be disastrous for various ecosystems on the earth, including humans as it would alter the conditions faster than some species could adapt to or migrate from. Some areas will become inhabitable because of droughts or floods following rise in the average sea level.

Greenhouse gases

The phenomenon that worries the environmental scientists is that due to anthropogenic activities, there is an increase in the concentration of the greenhouse gases in the air that absorbs infrared light containing heat and results in the re-radiation of much of the outgoing thermal infrared energy, thereby increasing the average surface temperature beyond 15°C. The phenomenon is referred to as the enhanced greenhouse effect to distinguish its effect from the one that has been operating naturally for millennia.

The greenhouse gases include carbon dioxide, chlorofluorocarbons, methane and nitrous oxide. These are the greenhouse gases present in the troposphere which result in an increase in the temperature of air and earth.

Impacts of enhanced greenhouse effect

The enhanced greenhouse effect will not only cause global warming, but will also

affect various other climatic and natural processes. They are as follows:

1. Global temperature increase: It is estimated that the earth's mean temperature will rise between 1.5 to 5.5 °c by 2050, if inputs of greenhouse gases continues to rise at the present rate. Even at the lower value, earth would be warmer than it has been for the past 10,000 years.

2. Rise in sea level: With the increase in global temperature, sea water will expand. Heating will melt the polar ice sheets and glaciers resulting in further rise in sea level. Current models indicate that an increase in the average atmospheric temperature 3degree C would raise the average global sea level by 0.2-1.5 metres over the next 50-100 years.

One metre rise in sea level will inundate low-lying areas of cities like Shanghai, Cairo, Bangkok, Sydney, Hamburg and Venice, as well as agricultural lowlands and deltas in Egypt, Bangladesh, India, China. This will affect rice productivity. This will also disturb many commercially important spawning grounds, and would probably increase the frequency of storm damage to lagoons, estuaries and coral reefs.

In India, the Lakshadweep Islands with a maximum height of 4 m above the sea level is vulnerable. Some of the cities like Mumbai may be saved by heavy investment on embankments to prevent inundation.

Life of millions of people who have build homes in the deltas of Ganges, the Nile, the Mekong, the Yangtze and the Mississippi rivers will be affected, by the sea level rise.

3. Effects on human health: Global warming will lead to changes in the rainfall pattern in many areas, thereby affecting the distribution of vector-borne diseases like malaria, filariasis and elephantiasis.

Areas which are presently free from diseases like malaria may become the breeding ground for the vectors of such diseases. The areas likely to be affected in this manner are Ethiopia, Kenya and Indonesia. Warmer temperature and more water stagnation will favour breeding of mosquitoes, snails and some insects, which are the vectors of such diseases.

Higher temperature and humidity will increase/aggravate respiratory and skin diseases.

4. Effects on agriculture: There are different views regarding the effect of global warming on agriculture. It may show positive or negative effects on various types of crops in different regions of the world. Tropical and subtropical regions will be more affected since the average temperature in these regions is already on the higher side. Even a rise of 2°C may be quite harmful to crops. Soil moisture will decrease and evapo-transpiration will increase, which may drastically affect wheat and maize production.

Increase in temperature and humidity will increase pest growth like the growth of vectors for various diseases. Pests will adapt to such changes better than the crops.

To cope with the changing situation, drought resistant, heat resistant and pest resistant varieties of crops have to be developed.

Measures to check global warming

To slow down enhanced global warming, the following steps will be important:

1. Cut down the current rate of use of CFCs and fossil fuel

2. Use energy more efficiently

3. Shift to renewable energy resources

4. Increase in nuclear power plants for electricity production

5. Shift from coal to natural gas

6. Trap and use methane as a fuel

7. Adopt sustainable agriculture

8. Stabilize population growth

9. Efficiently remove carbon dioxide from smoke stacks

10. Plant more trees

11. Remove atmospheric carbon dioxide by utilizing photosynthetic algae

Acid rain

Oxides of sulphur and nitrogen originating from industrial operations and fossil fuel combustion are the major sources of acid-forming gases. Acid-forming gases are oxidized over several days by which time they travel several thousand kilometres. In the atmosphere, these gases are ultimately converted into sulphuric and nitric acids. Hydrogen chloride emission forms hydrochloric acid. These acids cause acidic rain. Acid rain is only one component of acidic deposition. Acidic decomposition is

the total wet acidic deposition (acid rain) and dry deposition.

Rainwater is turned acidic when its pH falls below 5.6. In fact, clean or natural ~ rainwater has a pH of 5.6 at 200e because of formation of carbonic acid due to the \ dissolution of CO2 in water.

In the absence of rain, dry deposition of acid may occur. Acid forming gases like oxides of sulphur and nitrogen and acid aerosols get deposited on the surface of water bodies, vegetation, soil and other materials. On moist surfaces or in liquids, these acid forming gases can dissolve and form acids similar to that formed in acid ram.

Effects of acid rain

Acid rain causes a number of harmful effects below pH 5.1. The effects are visible even at pH less than 5.5.

1. It causes deterioration of buildings, especially made of marble, e.g., monuments like Taj Mahal. Crystals of calcium and magnesium sulphate are formed as a result of corrosion caused by acid rain.

2. It damages stone statues. Priceless stone statues in Greece and Italy have been

partially dissolved by acid rain.

3. It damages metals and car finishes.

4. Aquatic life especially fish are badly affected by lake acidification.

5. Aquatic animals suffer from toxicity of metals such as aluminium, mercury,manganese, zinc and lead which leak from the surrounding rocks due to acid ram.

6. It results in reproductive failure, and killing of fish.

7. It damages foliage and weakens trees.

8. It makes trees more susceptible to stresses like cold temperature, drought, etc.

Many insects and fungi are more tolerant to acidic conditions, and hence, they can attack the susceptible trees and cause diseases.

Control of acid rain

1. Emission ofS02 and N02 from industries and power plants should be reduced by using pollution control equipment.

2. Liming of lakes and soils should be done to correct the adverse effects of acid ram.

3. A coating of protective layer of inert polymer should be given in the interior of water pipes

MARIAN LIBRARY

Tuesday 10 January 2012

ENVIRONMENTAL MANAGEMENT-Unit 1

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MARIAN ACADEMY OF MANAGEMENT STUDIES