Free sample essay on Environmental Study

Environmental science as stated in the preceding section is basically the study of giving the total environment of the earth as a living planet, having both physical and biotic components.

The fundamental study unit of environmental science is the life supplying layer of the earth having atmospheric, lithospheric and hydrospheric components, which are responsible for the support of all types of life.

This life supporting layer, very commonly known as biosphere, is characterized by the operation of several physical and biological processes, mutual interactions and interdependence of abiotic and biotic components of the biospheric ecosystem, production and consumption of ecological resources, various positive and negative responses of interactions between different components of the environment, resulting into stability or instability of biospheric ecosystems at different levels (local, regional and global), environmental degradation and pollution arising out of the increasing pressure of economic and technological man on the environment and man’s renewed efforts and struggle to stabilize the disturbed ecosystem, to conserve and manage the ecological resources and to ameliorate environmental degradation and pollution through different pollution control and abatement programmes.

There are certain basic principles which govern the three basic aspects of environmental science, viz., natural processes, both physical and biological, in the life supporting layer (biosphere) and relationships between man and environmental processes, integrated functional unit of the biotic and abiotic components of the environment (ecosystem) and environmental degradation and pollution arising out of human activities and ecological resources and their conservation and management.

The following principles and concepts of environmental study may be identified:

1. Environment is a comprehensive term, which in general refers to surroundings. It includes abiotic (physical-land, air and water) and biotic (plants and animals including man and his several functions, organisations and institutions) components of the biosphere.

The earth is the only planet known to having different kinds of life forms wherein there are complex sets of interrelationships between the physical and biological components. Various linkages between physical and biological components at different levels maintain the unity of the ecosystem.

2. The dynamic evolving earth system in general and discernible processes, both physical and biological, in particular governs the biospheric system.

The physical or geological processes operate through a set of cycles, the broadest being geocycle. In fact, the endogenetic and exogenetic processes create different types of habitats on the earth’s surface for living organisms on the one hand and sometimes destroy the habitats on the other hand. The driving force of the endogenetic processes comes from within the earth. Endogenetic forces create different types of relief features of various magnitudes on the earth’s surface.

3. Various physical, chemical and biological processes are continuously engaged in the creation, maintenance and destruction of surface materials of the earth’s surface (both organic and inorganic). The process involved in the creation of the earth materials (inorganic) is known as ‘geologic cycle’ which includes a set of several sub-cycles, e.g., the hydrologic cycle, the rock cycle, the geochemical cycle and the geotectonic cycle.

The earth materials like minerals, rocks, soils, water etc. are not only created but are also maintained, changed in their properties, transferred from one place to another and even destroyed by geologic cycle; but these materials even passing through the aforesaid pathways remain initially uncontaminated and are very useful for man. Whenever these materials are used or dispersed by man, they become contaminated and are seldom available for human use because either they are dispersed to such locations, which may not be reached by man for fairly long period of time or they become so deformed and contaminated that they are not reusable.

Sometimes, some renewable natural resources (for example, water) are so contaminated that they become non-renewable. The biochemical cycles comprising several sub-cycles circulate bio­chemical elements, commonly known as nutrients (most important being oxygen, carbon, hydrogen, nitrogen, phosphorous and sulphur-S), through circular routes, in the various compartments (storage reservoirs) of the biosphere, e.g., atmospheric compartment or storage reservoir, sedimentary compartment or storage reservoir and organic compartment or storage reservoir. In other words, the cyclic pathways of the circulation of elements from inorganic phases to organic pathways and again back to inorganic phases are collectively known as biogeochemical cycles.

Thus the circulation of materials from different reservoirs of the inorganic phase through various pools of the organic phase in the biosphere determines the size of different reservoirs and pools on the basis of inflow-outflow. When the inflow of materials in a pool (compartment or reservoir) equals the outflow of materials from that pool (compartment or reservoir), the concerned pool is in steady state. When such equilibrium is maintained at the ecosystem level (equilibrium in all components of the ecosystem) this is called as ecosystem stability and such condition is very much useful for all organisms in general and mankind in particular.

4. The biological communities have affected, and continue to affect and alter the cycling of chemical elements/nutrients in the air, water and soils so much so to sustain life on the earth that the emergence of man and gradual increase in his technological skills have largely disturbed the biogeochemical cycles, which have resulted into depletion of certain natural resources at few places on the globe.

5. Physical/environmental and biological processes operate according to the law of uniformitarianism. James Hutton’s (Scottish geologist) law of uniformitarianism having two basic principles of ‘the present is key to the past’ and ‘no advantage of a beginning: no prospect of an end’, postulated in 1785, and related to ‘cyclic nature of earth’s history states that ‘all the physical laws and processes which operate today, operated throughout geologic time, although not necessarily with the same intensity as now.’

In other words, the very nature of the operation of physical processes remains almost the same throughout geologic history of the earth through their frequencies and magnitude may vary. The same law of uniformitarianism of geologic evolution of the earth applies to the biological processes and biological evolution at least from the date of the origin of atmospheric oxygen and appearance of life on Earth.

In other words, the biological processes, which operate today, might have operated in the past though with varying degrees of relationships between biological communities and physical or natural environment and between organisms.

6. Physical and biological processes operate in such a way that any change at any place in a specific time period is suitably compensated by negative feedback mechanism in a natural condition but human activities change and modify the frequency and magnitude of physical processes sometimes at the rate detrimental to human society. Man affects biological processes directly or indirectly. ‘From a biological point of view, we also know that the ultimate fate of every species is extinction! Direct impact of man on biological processes through purposive elimination of some species, domestication of some species and inadvertent increase of some species change the rate of extinction of species and alter the balance of population of species in a given region.

The increased land use changes mainly through the conversion of more and more natural ecosystems into agricultural land and urban complexes and industrial landscapes consequent upon phenomenal growth in human population has been responsible for extinction of a few species due to resultant adverse effect on ecological conditions of the region concerned. In fact, there has been parallel rise in human population and extinction of species of plant and animal communities.

Thus, it is of fundamental significance to study the present stage of operation of natural and biological processes in the light of interference of man through his economic activities so that the rate of changes of both natural and biological processes may be predicted and alternative strategies for environmental and ecological management may be formulated.

It is also significant to point out that catastrophic natural process like violent volcanic eruptions and outflow of immense volume of lava, widespread global climatic changes etc. would continue to eliminate some species of plants and animals, leading to extinction of species.

7. There is reciprocal relationship between biotic and abiotic (physical) components of the environment. The physical processes create suitable habitats for biological communities on the one hand and biological communities (mostly man) modify the environment on the other hand.

In fact, life has continued to modify and alter the atmospheric lithospheric and oceanic components of the biosphere since the very beginning of life. The very nature of the atmosphere, the rocks and sediments, fresh water on the earth’s surface and oceanic water in terms of organic and inorganic constituents have been greatly modified by the organisms including both plants and animals.

Since the dawn of environmental processes spearheaded by modern technologies to modify the environment, environmentalists besides studying the mode of operation of environmental and biological processes, must understand the nature of mutual interactions between environmental and biological processes before undertaking any programme of conservation of ecological resources and environmental management.

In this regard man and the consequent responses of such modifications of environmental processes to the total environment must pay particular attention towards the understanding of man-environment relationship with ecological approach and various ways of modification and alteration of environmental processes.

8. The ecosystem is a functional and well-organised and structured unit comprising biotic and abiotic (physical) components. In other words, it represents the sum of all-living organisms, dead organisms and physical environment of any space-time-unit of the earth’s surface ranging from the largest spatial unit as the whole biosphere to the smallest spatial unit, e.g., a cowshed or a plant. For life scientists, micro-level ecosystems are more important. The natural ecosystems are open systems characterised by continuous input of energy (solar radiation) and matter (nutrients) and output of energy and matter and they tend to be in relatively stable equilibrium unless there is disturbance in one or more controlling factors (limiting).

The most significant source of energy is solar radiation, which is trapped by the autotrophic green plants and is converted into heat energy through the process of photosynthesis. The energy flow is unidirectional as the energy lost through various organic components of the ecosystem at different trophic levels is not available again for use in the ecosystem.

There is a progressive loss of energy by respiration of organisms through increasing tropic levels. The nutrients are circulated in the ecosystem through several cyclic pathways collectively known as ‘biogeochemical cycles.

9. The energy flow and circulation of nutrients help in the sustenance of life on earth. It is significant to point out that ‘sustained life on earth is a characteristic of ecosystems, not of individual organisms or populations, i.e., to say all the organisms are interdependent in terms of production and consumption of food and recycling of organic and inorganic matter.

For example, autotrophic green plants are the primary producers upon which depend all the organisms directly or indirectly for their food but the autotrophic plants cannot decompose their dead organs. Similarly, micro-organisms do not produce their own food themselves but decompose dead organisms as well as their waste materials and receive their energy and chemical nutrition from the dead organisms.

Thus, it is apparent that efficient and complete recycling of nutrients in the various components of the ecosystems may be possible only when there are several species. This aspect of ecosystem diversity and complexity in terms of species reflects the stability of the ecosystems.

10. There are temporal and spatial variations in species. Darwin’s theory of evolution of species states that there is progressive evolution of species through the processes of natural selection and adaptation to environmental conditions, which led to gradual modification, and diversification of species over a long period of time.

Such variations in species increase progressively with each succeeding generation of species and the evolution of species continues. Some alternative processes of evolution of species have been suggested, e.g., mutation process (spontaneous evolutionary change in species) and reproductive isolation of morphologically differentiated population of species.

11. Individual populations are capable of rapid exponential growth, but this is rarely achieved in nature and control of the population is the norm. This principle is commonly known as ‘homeostatic mechanism.’

12. For example, if the population of certain insects in a specific area increases exponentially beyond the optimal level, the food supply would fall short of demand resulting in strong competition among the insects for food and consequent deaths of several insects and decrease in insect population. Such self-regulatory control of population is termed as density-dependent population control. In other words, density-dependent population control implies self-regulation of population of species due to decrease in birth, survival and growth rates and phenomenal increase in death rates. Besides, population of species is also controlled by such factors, which are not related to the birth, survival, growth or death rates, or population size of species.

Such factors are extreme events like severe atmospheric storms, which destroy the trees. Such population control is termed as ‘density-independent’ population control. Thus it may be summarized that ‘nothing- can increase forever.

The earth and the known universe are finite in space, matter and energy. In a finite universe, there is an upper bound to the size of everything. So, too, are the populations limited to a finite range.

13. The study of life forms in terms of their spatial distribution, temporal variations (evolution), dispersal and extinction at regional and global levels help in identifying the advantages and disadvantages of adaptation of certain species by man in different localities for his own purposes.

In other words, one can decide, while introducing and transporting exotic species to those areas, which have never been native places of such species, what kinds of species would be useful for inhabitants of the area concerned? Similarly, disastrous species may be identified and their introduction in new areas may be safely avoided.

This aspect of environmental study may prove very useful in natural resource management if the behavioural aspects of biological communities in relation to their reproductive characteristics as determined by the natural environment of the concerned ecosystem are properly studied and the findings are given due weight age in the planning process but till now this aspect has always been ignored.

14. There is a reciprocal relationship between environment and living organisms. In other words, environment provides habitats of varying kinds for different life forms and affects the life style of various organisms in different habitats having distinct assemblages of land, water, soil and climate, and in turn organisms affect and modify the environment.

This sort of mutual relationship makes the natural ecosystem more efficient. Of all the organisms, man is the most intelligent and powerful animal and is capable of not only affecting the environment like other organisms but affecting the basic composition of the environment at a scale detrimental not only to all biota but also to his own existence. Phenomenal increase in human population in the present century has put enormous pressure on natural resources which has resulted into accelerated rate of rapacious exploitation of natural resources in order to meet demands of the ever increasing population, rapidly growing industrialisation and urbanisation.

The developments of modern technologies and increased economic functions have further accelerated the rate of exploitation of natural resources. All these have contributed to the depletion or near depletion of a few precious non-renewable resources, degeneration of renewable resources (e.g., forest, grasslands, surface and groundwater etc.), environmental degradation and pollution at local, regional and global levels and above all ecological crisis. Environmentalists stress upon a symbiosis between man and the environment so that harmonious relationship may be established which may lead to the welfare of the human society.

15. It is therefore, imperative for environmental science to study the direct and indirect impacts of human activities on environmental/physical and biological processes, which lead to ecosystem instability and environmental degradation and pollution, the capacity and mechanism of natural/physical processes to absorb and adjust with the changes brought by man in the natural environment and to make sincere efforts for the identification and determination of levels of environmental degradation, pollution and ecological imbalance at different spatial and temporal scales, for the identification of real ecological and environmental crises, for the preparation of inventory of existing ecological resources, for the formulation of pollution control programmes and conservation and management of natural resources, taking the fact into mind that all the resources, even renewable and nonconventional (even the solar energy is also finite because the life of the sun is also fixed), are finite and we have moral obligation to our future generations.