We have all heard, read and used the word environment a number of times. But what exactly is environment. In simplest terms Environment comprises all of the external factors affecting an organism. These factors may be other living organisms such as animals and plants or non-living variables such as water, soil, climate, light, and oxygen. For instance in our case all organisms as well as the physical surroundings with whom we interact form our environment.
Principles of Environment:
To fully understand environment and its management we need to comprehend what I would like to call the three principles of environment:
1. All the constituents of the environment are interconnected
and dependent on each other.
2. Nothing comes free – there is always a price tag.
3. The world’s resources are in finite supply.
The first principle states that all the constituents of the environment are interconnected and dependent on each other.
Environmentalists have discovered that all species in an ecosystem interact with one another, either directly or indirectly.
American environmentalist Robert Paine, working in the rocky region of the Pacific coast, found stable invertebrate communities dominated by 15 species of animals. These included starfish, mussels, limpets, barnacles, and chitons. When Paine removed all the starfish from the area, the community collapsed, and eventually only 8 invertebrate species were left. The starfish were preying heavily on one of the mussel species and keeping its numbers down. With the starfish removed, the population of this mussel increased, and the mussel was able to out-compete many other species of invertebrates. Thus, the loss of one species, the starfish, indirectly led to the loss of an additional six species and a transformation of the community.
Another example concerns goats which were left on oceanic islands by sailors on their voyages. The goats were free to roam these islands and were meant to serve as a source of meat when the sailors later came ashore. Free from all natural predators, the goats thrived and, in the process, overgrazed many of the islands. With a change in plant composition, many of the native animal species were driven to extinction. A simple action, the introduction of goats to an island, yielded many changes in the island’s natural environment. This clearly demonstrates that all members of a community are closely interconnected.
Water, land and air - those are the systems which basically comprise our environment. How do they work – by maintaining a delicate balance!
Look into a pond. A fish feeds there on tiny plants and animals called plankton. In time, the fish dies. Micro-organisms in the water break the creature down into basic chemicals, consuming oxygen from the water in the process. Plant plankton, nourished by those chemicals, produce oxygen to replace it. Animal plankton feed on the plants, fish eat the tiny animals, and the cycle begins anew.
On land, too, nature moves full circle. Living things are nourished there, grow old and die, then decompose to enrich the land again.
A thin envelope of air surrounds the planet. We use its oxygen, exhaling carbon dioxide, which plants absorb. Plants use the carbon for growth by the marvelous process called photosynthesis, and return oxygen to the atmosphere. Thus nature's delicate balance is maintained.
The Second Principle:
The second principle states that nothing comes free – there is always a price tag.
In 1874 a German chemist named Othmar Zeidler created a new compound. Its name was a real tongue twister - dichloro-diphenyl-trichloroethane. We know it as DDT.
Dr. Zeidler was unaware that he had found a potential insecticide. Sixty-five years passed before the insecticidal properties were recognized—just before World War II. DDT was used extensively during the war, against mosquitoes and body lice, with great success. And thousands upon thousands of tons have been used since then, on forests, on farms, and to control household pests. Many an area has been freed at last from malaria.
But one of the compound's most attractive features—the fact that it remains active long after application—has had unpleasant results, too. In the past decade it has become increasingly evident that creatures in water, in air, and on land—including man himself—have built up concentrations within their bodies. Sharp reduction in a number of species of birds is attributed to DDT. The pesticide has traveled through the ocean chain. Even penguins in the Antarctic, where DDT has never been used, have accumulated traces of the compound.
Experts believe that DDT and its derivates aren't selective. This means that they aren’t harmful only to a select group of creatures. They are toxic to many forms of animal and marine life. Thus a product which helps us get rid of mosquitoes and was hailed as a wonder drug has been discovered to have properties which are extremely harmful.
It is quite clear that any technological innovation or any step which impacts on the environment has its costs. Nothing comes free. Environmentalists have a word for bargains like those. These are called trade-offs. Often the bargains are bad ones. For instance a small town lures a new industry. The obvious advantages are employment, growth, prosperity. In the process the industry more often than not pollutes the air, contaminates the local river and messes up the land.
The Aswan High Dam on the Nile was put there to expand irrigation, to generate electricity, and to control the annual flooding of the Nile Valley. Actually, those floods had helped keep the farms productive by fertilizing the land with silt. The dam has virtually ruined a sizable sardine fishery along the Nile Delta, because the nutrient supply has been choked off. The catch has fallen from 18,000 tons a year to less than 500 tons. And there's another problem, too: Snails are spreading through the irrigation ditches, carrying the harmful disease schistosomiasis.
There seems to be a law of nature that every benefit that is introduced to improve our happiness, our welfare, or our security has a cost factor someplace. Sometimes it's a money factor. Sometimes it's an environmental factor. And that's the real job for human ingenuity today—to develop concepts that will let us measure the benefits against the risks.
The Third Principle:
The third principle is based on the Law of Minimum according to which the world’s resources are in finite supply.
It has been said that there is enough in the world for man’s need but not for his greed. Man has been plundering natures for centuries with the mistaken belief that the supplies are endless.
As Gordon Young, a noted environmentalist writes, “We are astronauts—all of us. We ride a spaceship called Earth on its endless journey around the sun. This ship of ours is blessed with life-support systems so ingenious that they are self-renewing, so massive that they can supply the needs of billions. But for centuries we have taken them for granted, considering their capacity limitless. At last we have begun to monitor the systems, and the findings are deeply disturbing.”
Scientists and government officials now realize that we are in trouble. Unless we stop abusing our vital life-support systems, they will fail. We must maintain them, or pay the penalty. The penalty is death.
We have ignored the law of minimum feeling that the water, air and land are in infinite supply and whatever we do they are going to remain pure and pristine as ever. But sadly we have been proved wrong – terribly wrong.
Let us take water first. Why have so many of India’s rivers become casualties as the country grew? Shortsightedness? Not at first. When only a few settlements dotted a river's banks, the sewage that poured in caused little harm. The organic wastes were recycled into nutrients that nourished the tiny forms of life that fed the fish. The river purified itself before it reached the next settlement. This was a very convenient disposal system which few could resist.
Then villages grew into towns. The river stank a bit on hot summer days, but towns-people knew that the tainted water soon would be disappearing into the "limitless" sea. They were sure that these huge water bodies had infinite capacity to absorb all the filth that was being generated. Apparently they had not heard of the Law of Minimum. But now we realize that our oceans—those "limitless" seas that cover nearly three-quarters of the planet—are in trouble, too.
Statistics reveal that man puts at least three million tons of oil a year into the oceans. Unfortunately, most of the spillage happens in just the wrong places. Spills occur in the coastal waters, where marine productivity is concentrated. More than two million tons of oil a year comes from tankers that flush out their tanks at sea and from vessels that pump out oily bilge water. All too often, their wastes drift ashore to foul beaches.
Let us now move on to Air. Today much of the world suffers from the eye-smarting, lung-scarring curse we call smog. Usually found in urban areas, it is formed when nitrogen oxides react with hydrocarbons in the air to produce aldehydes and ketones. In New Delhi, Los Angeles, London and other great cities it comes in large part from automobile engines. In Tokyo things have come to such a stage that traffic policemen pause regularly to breathe oxygen.
We can clean up land before we use it, and purify water before we drink it, but—except in air-conditioned rooms—we must breathe air as it comes to us. Automobiles, factories, heating furnaces, power plants, each adds to the problem, so control is difficult.
And finally let us discuss the effect of our activities on Land. On an average Americans throw away 50 billion empty cans, 30 billion glass containers, 4 million tons of plastics, and more than a million television sets. Where does it all go? Into the ground, mostly, in open dumps or into "sanitary landfill." Incineration poses problems: Much of the refuse is unburnable. Also, some burning plastics produce toxic smoke, plus fume that damage an incinerator's pollution-trapping devices.
Landfill poses problems, too. Leaching chemicals sometimes pollute ground water. Rotting garbage can generate methane gas. Dumping sites for a city's trash are getting more and more difficult to find. If these things are happening in America today they are going to happen in the rest of the world tomorrow.
The lack of understanding and in some cases the violation of the three principles of environment has created a situation that is to say the least alarming. According to a report published in National Geographic, "Human beings and the natural world are on a collision course, which may so alter the living world that it will be unable to sustain life in the manner that we know."
The issues on the environment front are vast and diverse. Global warming, the depletion of the ozone layer, Acid rain, ground water depletion, habitat destruction and species extinction are just some of the problems that will reach critical proportions in the coming decades. Let us understand what these terms mean and what is their impact:
Green House Effect:
A green house is a glass building in which plants are kept to protect them from cold weather. Like the glass panes in a greenhouse, certain gases in the earth's atmosphere permit the sun's radiation to heat the earth but do not allow the infrared energy radiated by the earth to escape. This process is referred to as the greenhouse effect. These gases, primarily carbon dioxide, methane, nitrous oxide, and water vapour, insulate the earth's surface, helping to maintain warm temperatures. Without these gases, the earth would be a frozen planet with an average temperature of about -18° C instead of a comfortable 15° C. If the concentration of these gases were higher, more heat would be trapped within the atmosphere, and world wide temperatures would rise.
Within the last century, the amount of carbon dioxide in the atmosphere has increased dramatically, largely because of the practice of burning fossil fuels-coal and petroleum and its derivatives. Global temperature has also increased 1° C within the past century. Atmospheric scientists have now concluded that at least half of that increase can be attributed to human activity.
The consequences of even such a modest increase in temperature, termed Global Warming, may well be devastating. Sea levels will rise, completely inundating a number of low-lying island nations and flooding many coastal cities. Many plant and animal species will probably be driven into extinction, agricultural regions will be disrupted, and the frequency of severe hurricanes and droughts is likely to increase.
Depletion of the Ozone Layer:
The ozone layer, a thin band in the upper atmosphere, serves to shield the earth from the sun's harmful ultraviolet rays. In the 1970s, scientists discovered that the layer was being attacked by chlorofluorocarbons (CFCs), chemicals used in refrigeration, air-conditioning systems, cleaning solvents, and aerosol sprays.
The consequences of the depletion of the ozone layer are dramatic. Increased ultraviolet radiation will lead to a growing number of skin cancers and cataracts and also reduce the ability of people's immune systems to respond to infection. Additionally, the growth rates of the world's oceanic plankton, the base of most marine food chains, will be negatively affected, perhaps leading to increased atmospheric carbon dioxide and thus to global warming.
A significant portion of industry and transportation is based on the burning of fossil fuels. As these fuels are burned, chemicals and particulate matter are released into the atmosphere. Although a vast number of substances contribute to air pollution, the most common contain carbon, sulphur, and nitrogen. These chemicals interact with one another and with ultraviolet radiation in sunlight in various dangerous ways. sulphur dioxide and nitrous oxide are transformed into sulphuric acid and nitric acid in the atmosphere. When these gases come back to earth in precipitation, they form acid rain. Acid rain is a serious global problem because few species are capable of surviving in the face of such acidic conditions. Acid rain has made numerous lakes so acidic that they no longer support fish populations. It is also thought to be responsible for the decline of many forest ecosystems world-wide. Germany's Black Forest has suffered dramatic losses, and recent surveys suggest that similar declines are occurring throughout the eastern United States.
Ground Water Depletion:
Water that seeps through porous rocks and is stored beneath the ground is called groundwater. World-wide, groundwater is 40 times more abundant than fresh water in streams and lakes. However, even though groundwater is a renewable resource, reserves are replenished relatively slowly. In many countries such as the United States, approximately half the drinking water comes from groundwater.
When groundwater is depleted in coastal regions, oceanic salt water commonly intrudes into freshwater supplies. It is estimated that, on average, globally, 25 percent of usable groundwater is contaminated, although in some areas as much as 75 percent is contaminated. Contamination arises from leaking underground storage tanks, poorly designed industrial waste ponds, and seepage from the deep-well injection of hazardous wastes into underground geologic formations. Because groundwater is recharged and flows so slowly, once polluted it will remain contaminated for extended periods.
Habitat Destruction and Species Extinction:
It is believed that species are dying out at an unprecedented rate; minimum estimates are at least 4000 species per year. The leading cause of extinction is habitat destruction, particularly of the world's richest ecosystems-tropical rain forests and coral reefs. At the current rate at which the world's rain forests are being cut down, they may completely disappear by the year 2030. If growing population size puts even more pressure on these habitats, they might well be destroyed sooner.
There are many reasons why this loss is crucial. The economic value of species lost and of natural products and drugs that never will be discovered or produced is incalculable. As habitats are destroyed and species lost, the world is increasingly losing its richness and diversity.
Continued to: Our Environment: What Needs to be Done?
Images (c) Gettyimages.com