OUR EARTH – ON A KEG OF GUNPOWDER

Nothing on earth is more important to our survival than the air we breathe, the food we eat, and the water we drink. Inexorably, these life-sustaining essentials are being either contaminated or whittled away—by man himself. In some countries the state of the environment is already life-threatening. The weather can hardly be trusted, the sun is getting harsher by day and the water level which is going higher in water-prone areas carries the same story. Most countries like Holland are under water. Even in some part of Western and Southern Nigeria torrential rains and rising seas there have killed several million people and forced the remaining population into makeshift refugee camps on higher ground. There is an ominous pattern behind the recent droughts, the failed harvests, and the polluted air that suffocates city after city. They are symptoms of a sick planet, a planet that can no longer cope with all the demands man is heaping upon it. The threat is not one to be taken lightly. It calls for global attention and support.

Many scientists from around the world believe that global warming is here and that it will continue to worsen as developing countries push forward in industrial development. As this push is underway, developed countries are climbing higher, advancing from what they use to do to new innovation. Over three billion metric tons of carbon dioxide (CO2) are spewed out annually into the global atmosphere through the burning of fuels, such as coal, oil, and wood, for energy, and through deforestation burning. Therefore, the so-called greenhouse effect, resulting from the gases of fuel combustion, threatens to warm the atmosphere 3 to 8 degrees Fahrenheit by few couple of years.

Many believe that the increase of carbon dioxide levels is what has caused the rise in earth's temperatures. Other researchers, however, say that global warming is due particularly to our sun's variability—that the sun has been emitting greater energy in recent times. The future effects of the increase of temperatures on earth are hotly debated. But one thing global warming evidently has done is to complicate the already difficult task of weather forecasting.

Unfortunately, humans keep pumping a staggering amount of toxic gases into the atmosphere. Shocking reports of air pollution also come from many other industrialized countries.

Earth's trees, which absorb carbon dioxide and release oxygen, are among the victims of toxic air. Germany's trees are growing increasingly unhealthy, and air pollution continues to be one of the main reasons for the forest's failing health.

Some scientists believe that other gases released by combustion add to the greenhouse effect. Nitrous oxide for one, and chlorofluorocarbons

(CFCs) for another. In fact, each CFC molecule is 20,000 times as efficient at trapping heat as one molecule of CO2. CFCs have also been targeted as the main cause for the thinning of the ozone layer, which protects life on earth from harmful ultraviolet rays. The ozone at the North Pole and the South Pole has thinned sufficiently to cause holes.

That is more bad news for corals. Experiments exposing miniature coral reefs that were already stressed by warm water to tiny increases in ultraviolet light aggravated bleaching. I am of the view that even if chlorofluorocarbon emissions stopped today, chemical reactions causing the destruction of stratospheric ozone would continue. The reason is

simple: the compounds remain that long in the atmosphere and would continue to diffuse into the stratosphere from the tropospheric reservoir long after emissions had ceased.

Such reports come from around the world. No country is immune. From Nigeria to China down to Australia and Greenland the story is the same. With chimney stacks that reach high into the sky, industrialized countries export their pollution to neighboring lands. Man's record of greedy industrial development does not inspire hope. The consequences of less ozone in the upper atmosphere are not fully understood. One thing that seems certain, however, is that the amount of harmful UV

(ultraviolet) radiation reaching the earth is increasing, resulting in a greater incidence of skin problem and more.

What are the Chlorofluorocarbons? They are long-lasting chemicals used in refrigerators and air conditioners and as foaming agents in insulation. In the upper atmosphere, they destroy ozone, a gas that is beneficial because it absorbs dangerous solar radiation that can cause skin cancer. The discovery of a safe refrigerant decades ago that could replace others that were toxic and gave off a bad odor. The new chemical was composed of molecules having one carbon, two chlorine, and two fluorine atoms (CCl2F2). It and similar man-made chemicals are called chlorofluorocarbons (CFCs). By the early 1970's, the production of CFCs had grown into a huge worldwide industry. They were being used not only in refrigerators but also in aerosol spray cans, in air conditioners, in cleaning agents, and in the manufacture of fast-food containers and other plastic-foam products.

After CFCs leak from their discarded air conditioners and crumpled plastic foam cups, they slowly drift up to the stratosphere. There, bombarded by ultraviolet rays, they break up at last, releasing a real ozone killer: chlorine. Its molecules dance a deadly minuet with the fragile ozone molecules, destroying them and spinning off intact to find another unfortunate partner. One chlorine molecule may dance on in this way for over a century, obliterating a hundred thousand ozone molecules.

What of the greenhouse? The Greenhouse Effect: The earth's atmosphere, like the glass of a greenhouse, traps the sun's heat. The sunlight warms the earth, but the heat that is created—carried by infrared radiation—cannot easily escape the atmosphere because the greenhouse gases block the radiation and send some of it back toward the earth, thus adding to the warmth of the earth's surface When the atmosphere absorbs infrared radiation caused by these chemicals, it acts like a blanket around our planet. Sometimes we forget that the earth is surrounded by cold, empty space. Even though the sun warms the earth, without our greenhouse “blanket,” that heat would rapidly escape, and the temperature at the surface would be 70 degrees Fahrenheit [40° C.] or more colder than it presently is. The oceans would freeze!

The problem with the greenhouse effect is that it may become too much of a good thing. A runaway greenhouse effect could mean mass starvation as grain belts turn to dust bowls. It could also mean superkiller hurricanes powered by extra warm oceans, rising oceans flooding coastal areas, rampant skin cancer brought on by an eroding ozone layer, and untold human misery. Burning fossil fuels, whether in power stations or in domestic furnaces, produces other pollutants in addition to sulfur dioxide. These include oxides of nitrogen and unburned hydrocarbons.

What effect does all of this have on man? He suffers when lakes and rivers formerly teeming with life become acidic and lifeless. Hence, while acid rain is killing waterways, many feel that ozone, linked ultimately to automobile exhausts, is more to blame than acid rain for the death of trees. Trees are being prematurely killed not by acid rain but by ozone. Though the death blow may be delivered by frost, acid mist or disease, it is ozone that makes the trees vulnerable. And what is happening in Africa merely mirrors the conditions on other continents.

What is the ozone layer? How does it work, and how are we destroying it? Well, ozone is an unstable form of oxygen. It has three atoms of oxygen (O3) instead of the usual two (O2). Ozone occurs naturally in the stratosphere, absorbing the dangerous UV-B rays while allowing the needed and safe light to pass through. Furthermore, while ozone is easily broken down by other gases, in the stratosphere it is constantly being created by the sun's rays. So it is a self-repairing shield. Quite a design!

Because CFCs are said to be contributing to the rapid depletion of the earth's protective ozone layer. The ozone in the earth's upper atmosphere plays a vital role in filtering the sun's ultraviolet rays, which can cause skin cancer and cataracts. This is a problem not just in Australia. Recently, scientists have detected an 8-percent decrease in winter ozone concentration above some temperate regions of the Northern Hemisphere. Twenty million tons of CFCs have already drifted up toward the stratosphere. This seasonal drop in ozone is called the ozone hole. Moreover, in recent years the so-called hole has been getting bigger and lasting longer. In 1992, satellite measurements revealed an ozone hole of record size—larger than North America. And not much ozone was left in it. Balloon measurements revealed a drop of more than 60 percent—the lowest ever recorded.

Scientists skirmished for a while over the cause of the hole. But instrument-laden planes flying through the ozone hole itself found the real culprit—chlorine from man-made chemicals! High above the South Pole is a huge vortex with clouds composed of tiny ice particles, giving the chlorine millions of tiny surfaces upon which it can do its deadly dance with ozone even faster.

The problems arise when man starts to inject his own industrial gases into this delicate system. Then ozone is destroyed faster than the sun's rays can produce it. In 1974 scientists began to suspect that CFCs, or chlorofluorocarbons, are ozone-destroying gases. Yet, these CFCs are everywhere. They are used to make all kinds of foamed plastic products, from insulation to cups and fast-food containers. They are used as propellants in spray cans, as coolants in air conditioners and refrigerators, and as solvents to clean electronic equipment.

In the stratosphere, ozone is beneficial because it absorbs dangerous ultraviolet radiation that can cause skin cancer if it penetrates to earth's surface. But in the lower atmosphere, ozone is a hazard. Ozone is a by-product of combustion, especially in automobiles and jet aircraft.

Ozone is indeed a lifesaver. But down here in the troposphere, ozone is produced as a by-product of human pollution. Humans release huge amounts of hydrocarbons into the air, mostly by burning gasoline in automobiles. Sunlight acts on these hydrocarbons to produce ozone.

Effect of Pollution
The future effects of the increase of temperatures on earth are hotly debated. But one thing global warming evidently has done is to complicate the already difficult task of weather forecasting. Humans are not meant to breathe ozone. It causes lung damage. In fact, scientists have recently realized that it is even more dangerous to human health than previously thought. Some have called out urgently for tighter restrictions on ozone pollution—to little avail.

But as a result of man's increased use of fossil fuels, the amount of carbon dioxide has reached over 350 parts per million. Many believe that the increase of carbon dioxide levels is what has caused the rise in earth's temperatures. Other researchers, however, say that global warming is due particularly to our sun's variability—that the sun has been emitting greater energy in recent times. The effects of the resulting increase in UV-B rays reaching earth's surface will be far reaching. These rays cause skin cancer in humans. They also damage the human immune system and cause cataracts.

What of the effects of these gasses? They damage paint and other building materials, cause disease in trees, plants, and crops, and appear to trigger respiratory problems in some people. Although most of the ozone pollution occurs in towns, surprisingly it is the rural areas that suffer the worst effects. In the urban areas, nitrogen oxides mop up the excess ozone, but where these oxides are sparse, the ozone has free rein to wreak damage.

These changes are going to affect every human being and every ecosystem on the face of the earth, and we only have a glimmer of what these changes will be. Increased UV-B radiation will destroy the tiny krill and other plankton that live near the ocean's surface, disrupting the ocean's food chain. Wholesale destruction of plant life, crop losses, even changes in global wind and weather patterns, could result from a weakened ozone layer. If any of these threats materialize in the coming decades, it will certainly spell trouble for man and his world.

Although effect may be invisible sometimes, its deadly harvest is not.

You can see it wherever you look: people dying of cancer and respiratory ailments; defaced buildings and monuments; decimated animal and plant life; rivers depleted of fish; dead and dying forests. Now another phenomenon has made its appearance, seemingly bearing pollution's trademark. Scientists have discovered a hole in the ozone layer surrounding the earth. And it is getting bigger. Some feel that chlorofluorocarbon pollution is apparently a factor, resulting from extensive use of aerosol sprays. Will the damaging of this ozone layer, which helps filter out harmful solar radiation, cause an upsurge in more deadly damage to health? Or perhaps cause something even worse?

Why the Difficulty in Predicting the Greenhouse Effect

The earth's overall climate is an enormously complicated system, and scientists freely admit that there are limits to what they can predict. Here are a few of the factors that could greatly influence current computer models of future climate.

MELTING SNOW AND ICE: Ice and snow reflect 40 to 60 percent of the sun's incoming rays. This has the effect of cooling the planet. But as rising temperatures cause ice and snow to melt, the darker land or water underneath will absorb more heat. This could amplify the greenhouse effect, perhaps by 10 to 20 percent or more.

CLOUDS: A warmer earth should mean higher global humidity—more clouds. Cloud feedback is one of the largest sources of uncertainty in the theory of climate change. It is thought, however, that more clouds would tend to cool things off by increasing the reflection of solar energy.

On the other hand, while clouds reflect away some solar energy, they also act as blankets to trap radiation coming up from the surface. So it is hard to predict which effect would predominate in a warmer, cloudier world.

THE OCEANS: Water is an excellent heat absorber, and it appears that the oceans can store enough heat to delay the full onset of the greenhouse effect by decades. Just how much delay is difficult for scientists to predict.

VOLCANOES: Volcano-induced clouds warm the stratosphere and cool the surface of the earth in a complex way. Overall, volcanoes would probably tend to reduce the greenhouse effect, but no one can predict when a big one will erupt.

SOLAR CYCLES: Contrary to what many people think, the sun's output is not absolutely constant. Its brightness diminished steadily and repeatedly. This makes the increasing global temperature during that period seem all the more ominous.

Managing the Greenhouse Gases
WATER VAPOR: The amount of water vapor in the air depends mostly on the temperature. Warm air can store more moisture than cool air can.

Water vapor absorbs heat very effectively, but it cannot give rise to the greenhouse effect by itself. Water vapor serves mostly to amplify the effects of the other gases.

CARBON DIOXIDE (CO2): It is the most prevalent of the heat-trapping gases and is vital to all life on earth because plants need it to live. The amount of carbon dioxide in the atmosphere is currently increasing by a half percent per year. That may not sound like much, but it means that about one ton of carbon for every man, woman, and child on the planet is put into the atmosphere each year from burning fossil fuels, such as coal and oil—5,000,000,000 tons of carbon per year! About half of that carbon is eventually used by plants or is absorbed by the ocean, but the rest stays in the air.

METHANE (CH4): This is the chief component of natural gas. Like carbon dioxide, it contains carbon. It is increasing twice as fast as carbon dioxide in the atmosphere, or about 1 percent per year. There is already twice as much methane in the air as there was in preindustrial times. Scientists are concerned that the increasing concentration of methane may make it more difficult for the atmosphere to decompose other greenhouse gases, such as the infamous CFCs (chlorofluorocarbons).

CFCs: These long-lasting chemicals help destroy ozone after they have risen to the stratosphere. But they are powerful greenhouse gases while in the lower atmosphere. In fact, molecule for molecule, they are about ten thousand times as effective as carbon dioxide when it comes to absorbing infrared rays!

NITROUS OXIDE (N2O): When your dentist used this, he may have called it laughing gas, but its effect on the atmosphere is no laughing matter. It is a by-product of burning fossil fuels and is extremely stable. Once it gets into the atmosphere, it stays there on the average for 150 years. During that time, it absorbs heat while in the lower part of the atmosphere, called the troposphere, but it can also rise to the stratosphere, where it helps to destroy ozone. The concentration is currently growing at 0.25 percent per year.

Efforts and solutions
There has been increased fight to protect the earth from total collapse. The 1987 Montreal Protocol, which involved an international agreement to phase out chlorofluorocarbons (CFCs) within a set time limit. Has this protocol impacted on the system? On a global level, alarmed scientists and leaders conclude that the solution is beyond one nation or even a group of nations. Pollution is carried around the globe by circling currents of air and water, impacting the reefs.

Individual nations have no jurisdiction beyond their territorial waters. Pollutants dumped on the high seas eventually end up on the shores. A unified global effort and solution are needed.

Hardly. Self-interest affects decision makers as well as the general public are not well-informed and are not truly interested to make this call laudable. Politicians are reluctant to implement environmental policies that might cost them votes, and industrialists balk at any proposals that may threaten profits and economic growth. Powerful voices in government and industry strongly opposed regulations, on the grounds of incomplete scientific evidence. Powerful industries lobby to minimize pollution control or to avoid government regulations altogether. What of the reliable tools that are in place to give data?

As it turned out, though, computers receiving data from satellites are programmed to reject as erroneous any drop in ozone of more than 30 percent. The machines had been measuring the ozone hole for years but throwing away the data!

1 SOLAR ENERGY: The use of solar energy has faded from public view in recent years, largely because of falling oil prices. In the meantime, however, dramatic gains have been made in the efficiency of solar cells. As The New York Times reported recently, for the first time, “the conversion of solar energy to electrical power could become comparable in efficiency to conventional power generation.” If solar energy becomes truly competitive, this technology could help reduce greenhouse emissions as solar power plants replace conventional ones.

2 HYDROGEN FUEL: This is an idea that is at least technologically feasible—the use of pure hydrogen, instead of petroleum products, as a fuel for airplanes and perhaps even automobiles. From a 'greenhouse'

standpoint, the advantage of hydrogen fuel is that it is very clean burning. There is no carbon dioxide produced at all in hydrogen combustion, just steam. Hydrogen is an excellent source of energy. In fact, pound for pound it will keep an airplane flying for three times as long as jet fuel will. One problem is that it is also three times as expensive. A larger problem is that liquid hydrogen must be kept very cold and under pressure. Any leaks in the fuel system could lead to a disastrous explosion, as in the case of the American space shuttle Challenger.

3 SPACE SHIELDS: Huge “parasols” in outer space made of thin plastic that would cast giant shadows on the earth have been proposed. It would require satellites with an area equal to 2 percent of the earth's surface to compensate for the anticipated doubling of carbon dioxide. This plan would not be popular with astronomers!

4 GLOBAL REFORESTATION: Did you know that highly efficient, nonpolluting, self-maintaining devices already exist for carbon dioxide removal from the atmosphere? They are plants. Green plants use carbon dioxide as food, keeping the carbon for their own use and returning the oxygen to the air as waste matter. All things being equal, an increase in carbon dioxide should stimulate plant growth worldwide, which would tend to use up the extra carbon dioxide and help control the greenhouse effect. But, sad to say, all things are not equal where plants are concerned. The plants that are able to remove the most carbon per acre are trees, and trees are being chopped down all over the world at an appalling rate.

In the face of this global trend, many scientists are urging massive reforestation to combat the greenhouse effect. They point out, for example, that ten million acres [4,000,000 ha] of trees could absorb all the carbon dioxide emitted by power plants in the next ten years.

Programs to reach this goal at a cost of thousands of millions of dollars were discussed at Senate hearings in the United States a year ago.

Tree-planting incentives are not very appealing to starving, desperate people where trees are being destroyed to clear land for crops.

However, the world's tropical rain forests are part of the oxygen-producing lifeline for the entire planet, and they are being slashed, burned, and butchered. Will the lifeline be cut?

5 CFC DEATH RAYS: Giant lasers could be fired from earth into the atmosphere, tuned to energy frequencies that chlorofluorocarbon gases absorb. Hopefully this energy will blast apart the CFC molecules before they rise to the stratosphere and attack the ozone layer.

Problems with this include the expense and energy requirements of the lasers and “whether you can get the laser's energy absorbed by CFC's and not other molecules, such as water vapor and carbon dioxide,”

according to Princeton University physicist Thomas Stix.

6 SOLAR POWER SATELLITES: Giant arrays of solar cells in space could collect solar energy continuously without stopping for clouds or night. The energy would then be beamed down to earth as microwaves or laser beams. The idea is to use solar energy instead of burning more fossil fuels. The technical obstacles and scale of the project are daunting.

Conclusion
While it is not possible to have all hands accept the massive destruction of our earth due to selfishness and ignorance attached to it, it is responsible to create a will that will serve as a compass to the unborn generation. With this in mind, it is reasonable to conclude that only few are aware of the proportions of the potential tragedy.

The authors believe that the planet can only be saved if politicians and businessmen face up to reality and think in terms of long-term viability instead of short-term benefits. So while hopes for a solution do exist, scientists are shaken. They have learned that the earth's atmosphere is an enormously complex and delicate mechanism; it responds to human pollution suddenly and unpredictably. Although some laudable progress has been made, it has mainly been cosmetic, addressing symptoms rather than causes. If a house has dry rot, painting the woodwork will not prevent its collapse. Only a major structural reform can save it. Similarly, there must be a restructuring of the way we will help build this future the way we want it. Well in our own little way, we can plant a tree and help restore your place of living by avoiding littering and use of harmful substance. We can also talk. We can do something more than talking. It calls for personal dedication to the course and choice of making the earth a theatre of happiness and hope for our generation and those coming behind. We make this possible not by advocating some new public enterprise but through our devotion and love and patience and kindness to the earth and people who live far away from us. We make the world a better place one minute and one person at a time. Without kindness in our lives, our world can quickly turn cold, empty and negative. Kindness gives us hope, it connects us to each other and it reminds us of the beauty that lives in each of us. How so? Celebrate your own purposeful actions, as you participate in your homes, schools, communities, towns, states, country and the world how to restore the earth to its beauty. We all have the power to make a difference in others' lives. Through our intention and actions, we choose to bring positive experiences into our lives and make them for others. We can all do something. Do what you can. Do what looks like it needs doing. Do it your own way. Do it because you want to. Do something because you know you can.

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During the past half century, the growing demand for food, freshwater, timber, fiber, and fuel has caused unprecedented changes in earth's ecosystems, straining earth's ability to sustain future generations.

Earth's natural ability to pollinate crops, provide air conditioning by wild plants, and recycle nutrients by the oceans is being overtaxed. The planet is also at the edge of a massive wave of species extinctions. Humans are damaging the planet at such an unprecedented rate that they are raising the risk of abrupt collapses in nature that could spur disease, deforestation or dead zones in the seas. The wetlands, forests, savannahs, estuaries, coastal fisheries and other habitats that recycle air, water and nutrients for all living creatures are being irretrievably damaged. There seems to be little hope for the future of the hope. This essay from a modest beginning highlights the effect of threatened biodiversity and ecosystem to the planet earths and its inhabitants .It also identifies and recommend collective sustainable grassroots efforts and global steps to be taken to correct these problems. It concludes by describing some of the benefits that are expected to be derived from these suggestions and way forward for our world if the above recommendation is carried out within a targeted timeframe, for a prosperous and healthy earth. This essay though is optimistic that it lies within the power of human societies to ease the strains that are being put on the ecosystems, achieving it will require radical changes in the way nature is treated at every level of decision-making What constitutes biodiversity and ecosystem and how important are they? Humans, with all their advanced technology, create countless tons of unrecyclable toxic waste annually. Yet, the earth recycles all its wastes perfectly, using ingenious chemical engineering. Life on earth is dynamic and interrelated. We humans are an intrinsic part of it. We depend on the living world for our food and medicines, the oxygen we breathe, and the elements that form our bodies. All of earth's species together weave a complex, astonishing, and intricate web of life.

Life on earth is abundant and immensely diverse. The term “biological diversity,” or “biodiversity” for short, designates all the world's species, ranging from the smallest bacteria to the giant sequoias; from earthworms to eagles. All this life on earth is part of one great, interdependent web that also includes nonliving elements.

Life depends on nonliving components such as earth's atmosphere, oceans, fresh water, rocks, and soils. This community of life is called the biosphere, and humans are an integral part of it.

Also, the term “ecosystem” refers to the complex interaction of all organisms within a natural environment, including living and nonliving matter.

Biodiversity embraces all the bacteria and other microbes. Many of these are known to perform vital chemical functions that keep ecosystems operating. Biodiversity, or the web of life, also includes the green plants that produce oxygen through photosynthesis, trapping solar energy and storing it in the form of sugars, which are the base of energy resources for most other forms of life.

If a city's supply of fresh air and water were cut and its sewers blocked, disease and death would soon follow. But consider: Our planet is not like a restaurant, where new food and supplies are shipped in from outside and garbage is carted away. The clean air and water we depend on are not shipped in from outer space, nor is waste matter rocketed out. So how does the earth remain healthy and habitable? The

answer: the natural cycles, such as water, carbon, oxygen, and nitrogen cycles.

Fresh air is just as important as the food we eat. As anyone who enjoys a bracing forest walk has noticed, trees do an invaluable job of replenishing the atmosphere with oxygen. But when they are burned, carbon in the form of carbon dioxide and carbon monoxide is released.

Both gases cause problems. Carbon monoxide is even worse. It is a principal lethal ingredient found in the smog that is the bane of city suburbs.

Survival Threatened
Hence, the voices of conservationists are still being drowned out by the whine of power machinery and the crash of falling trees, leaving behind denuded land. Soil is eroded, debris is washed into streams.

Because of having no forest cover, streams are becoming too warm for fish to inhabit. Wildlife deserts the land. In tropical moist forest areas the ground becomes hardened by the heat of the tropical sun, unable even to support grass.

Without doubt, many of man's actions have been well intended. But as is so often the case, we simply do not know enough about the environment to predict the consequences of our actions accurately. The results have been devastating. The chief contemporary cause of the loss of genetic diversity has been the spread of modern, commercial agriculture. The largely unintended consequence of the introduction of new varieties of crops has been the replacement—and loss—of traditional, highly variable farmer varieties.

Despite our dependence on the diversity of life, however, the world seems to be in the midst of an extinction crisis that has threatened the intricate web of life. Now at a time when we are beginning to understand the vital role of biodiversity, humans are causing more extinctions than ever before. What other areas has man contributed in this foreseen tragedy?

▪ Habitat destruction. This ranks as the leading cause of extinction.

It includes logging, mining, clearing trees for cattle, and building dams and highways where wilderness once existed. As ecosystems shrink, species lose the resources they need to survive. Natural environments are fragmented, degraded, and eliminated. Migration routes are disrupted. Genetic diversity diminishes. Local populations of living things cannot rebound from disease and other stresses. Hence, one by one, species gradually die out.

For example, in most African countries, in order to provide a steady supply of food in that country, farmers had no choice but to rely on chemical fertilizers and pesticides to meet society's demand. has led to underground water pollution—which

▪ Introduced species. When humans introduce a foreign species into an ecosystem, that species may take over niches that other species have occupied. The foreign species might also indirectly change the ecosystem enough to force out native species, or it might bring with it diseases to which the natives have no immunity. Especially on islands, where species have long existed in isolation and have not dealt with newcomers, the original inhabitants may be unable to adapt and survive.

Threat of global warming. According to the Intergovernmental Panel on Climate Change, it is possible that temperatures could rise by as much as 6.3 degrees [3.5°C] Fahrenheit within this century. This may be too fast a jump for some species to survive. According to researchers, it appears that a contributing cause of the death of coral reefs (anchors of much of marine biodiversity) is warming water.

Scientists say that a three-foot [1 m] rise in sea levels could eliminate a large portion of the world's coastal wetlands, the home of abundant biodiversity. It is believed by some that global warming may be affecting the Greenland and Antarctic ice sheets. If these were to melt, environmental catastrophe could follow.

▪ Overexploitation and Human population growth.. This has led several species to extinction. A classic case is that of the passenger pigeon.

The human family in the mid-19th century had a population of one billion. One and a half centuries and five billion people later, humans are beginning to wonder whether they are in danger of exceeding the limits of their resources. Each year, as the human population continues to grow, species are becoming extinct at an alarming rate.

Deforestation and Nitrate-rich runoff: A man can live about a month without food, but he will die in about a week without water. Hence, declining supplies of fresh water as seen in many parts of the world will be a source of increasing tension in coming years, because many do not have easy access to clean drinking water. Water shortages occur for a variety of reasons. Many rivers are in a very poor state of health and it is as a result of nitrate-rich runoff, which comes primarily from fertilizers used for farming.

Erosion occurs naturally and is generally not a serious problem—unless man accelerates the process through poor land management. Other factors such as deforestation and overgrazing, have accelerated the expansion” of desert areas. By clearing forest to plant cereal crops, farmers have irretrievably destabilised the thin soils. It is estimated that after a plot has been cleared of bush, within three years it loses up to 50 percent of its fertility. Millions of hectares are already beyond recovery and millions more are heading that way as agricultural yields in some areas decline year by year. When soil is stripped of vegetation, the bare topsoil soon dries out and is blown away by wind or washed away by water. This process is called erosion.

The Green Revolution: Through massive government and corporate campaigns, farmers in famine-prone lands were persuaded to replace their diverse crops with uniform, high-yield grains, particularly rice and wheat. These “miracle” grains were hailed as the solution to world hunger. But they were not cheap—seeds cost up to three times the normal price. Yields also depended heavily on chemicals, including fertilizers, not to mention such costly equipment as tractors. Still, with government subsidies the green revolution took off. While it has saved millions from starvation. It is now threatening the world's food security.

In effect, the green revolution may have provided short-term gains at the cost of long-term risks. Uniformity of crops soon became commonplace across entire continents—while the intensive use of fertilizers encouraged weed growth, and pesticides destroyed beneficial insects as well as pests. In rice paddies, toxic chemicals killed fish, shrimps, crabs, frogs, and edible herbs and wild plants—most being valuable supplementary foods. Chemical exposure also led to cases of poisoning among farmers. Unfortunately, the monoculture crops introduced since the 'Green Revolution' have adversely affected biodiversity and food security all over the world.

The genetic diversity present in cultivated plants a century ago is now lost, mainly because of industrial farming practices.

A way out
Voices are being raised in alarm. The destruction of existing ecosystems would upset all manner of delicate ecological balances and would entail the irreversible destruction of an enormous source of oxygen which is crucial for the survival of the biosphere. The consequences of man's assault on the mountains are already being felt.

Floods, landslides, and water shortages are just some of the signs that all is not well. Governments have begun to take notice. Forests are being replanted, and logging is banned in some areas. National parks have been created to safeguard the most spectacular scenery and the most endangered wildlife habitats.

Of course, the best way to reduce extinction is to protect native habitats and revitalize diversity in crops. But to do that, we need to develop a new balance between human needs and those of the natural world. How realistic, though, is it to think that humans will develop a new balance with the natural world while they pursue industrial and economic progress with almost a religious zeal? Even agriculture, as we have seen, is being assimilated into the high-tech, market-driven world of big business. There must be another answer.

There are environmental scientists who feel that the role of biodiversity is still poorly understood and perhaps exaggerated by some of their colleagues. Still, as scientists debate the matter, it seems worthwhile to take note of the cry of alarm coming from some experts in this field. They seem troubled, not only by the loss of biodiversity but also by the greed and shortsightedness they see at work behind such losses.

Planting of trees can make a difference somehow. People should be made to see the need. Though, trees take time to grow. Hence, rapid-growth “supertrees” are being experimented with, the hope being to help prevent further shrinkage of the world's woodlands. These can grow as much as 50 feet in a year, can stop forest fires from spreading and can inhibit soil erosion.

A further conservation measure is the emphasis being put on using what was formerly discarded. Only 43 percent of cut timber is at present being put to good use. Through modern research, mill residue is being turned into particle board. Roofing and insulating materials, filler for linoleum, tannin and medicines are being produced from bark. Short lengths and crooked logs unsuitable for lumber are being milled into squares for use in making furniture legs, as well as handles for tools or toys. As research continues it would seem, that wood can be developed to satisfy almost every requirement of human and animal existence, and thus become civilization's most significant raw material.

In a way of summary, we need natural ecosystems to provide essential services on which all living things depend. The production of oxygen, the purification of water, the filtering of pollutants and the prevention of soil erosion are all vital functions performed by healthy ecosystems. Insects provide pollination services. Frogs, fish, and birds control pests; mussels and other aquatic organisms cleanse our water supplies; plants and microorganisms create our soils. The economic value of all these services is immense. If we are to solve the threat of biodiversity and ecosystem, all of the world's people must embrace a balance view of what our planet earth needs. The transition will not be simple and it will require all of us to act, but through ingenuity and compassion, a brighter future is possible.

It is human that generate ideas, create opportunities provide manpower which direct the other sources of production and ultimately, direct their thinking and that of others. Let's work together now using what we have as a means hoping that other means of promoting a healthy earth will naturally emerge. By showing love and reciprocity, understanding and solidarity, we join hands in support of this urgent call. And once we are through, we encourage recipients of our selfless spirit and collective action to show similar concern. There is hope.