World environment at risk

Miran Perera

ENVIRONMENT: Sri Lanka is famed the world over for her rich biodiversity. That this could well be a gross overstatement in this new millennium in the light of recent evidence is indeed cause for grave concern.

As indicated by a study carried out by the Sri Lanka office of the IUCN or International Union for the Conservation of Nature the fate of thousands of species sharing our motherland hangs precariously in the balance.

The natural world has always been in a state of flux. That cliche (The balance of nature) was never true. Lakes turn into marshes, grasslands become deserts, glaciers advance and retreat, new species evolve and others become extinct.

These changes for the most part take centuries if not millennia and move at such a pace that new populations of animals and plants are able to establish themselves and so maintain the continuity of life. Such processes are implicit in much that a naturalist observes.

For many of us the present world environment represents the dilemma facing thousands of species on our planet whose future lie in the doom of uncertainty. The planet is or on the verge of an extinction crisis.

Even the most conservative estimates point out that we would lose some 17,000 - 35,000 species a year for the next hundred years.

More conclusive studies reveal that 25% of mammalian species, 16% of bird species, 12.5% of species of plants and 10% of tree species the world over are threatened with extinction placing the entire biosphere itself at risk. International rescue efforts are however costly in preserving the dwindling species for a developing country like Sri Lanka.

The cost of captive breeding a critically endangered species its subsequent reintroduction to the wild and the continuous monitoring ended to ensure its survival could well be prohibitive.

Thus for many countries like Sri Lanka prevention is a better option than the costly one of cure. We need to focus on conservation action that can stein the tide of extinction that is slowly but surely threatening our species.

According to Botanist Peter Raven Director of the Missouri Botanical garden in St. Louis in the past 200 years just one of the millions of species inhabiting the earth humans has threatened all the rest putting civilisations itself at risk. What can be done?

Raven sees the answer in a metaphor. If you view the human race as if it is floating down a river he says, then we are riding the rapids. We must put our oars in the water take but our poles and chart a sustainable course.

You do not have to be a sharp eyed scientist to be aware of the changes that are taking place today. A forest mantling a hill side in Malaysia is felled before our eyes within a month. Hedge rows that have sheltered rich communities of wildlife in Britain are grubbed up overnight.

A valley in South America 100 miles long is totally submerged and turned into a 580 square mile lake in only 14 days. A plot of forest in Brazil still undamaged jungle or expanse of trees is so vast that mans impact on it must be negligible. Not so. The earth’s surface today is surveyed regularly by satellite from outer space. We now know beyond argument the scale and the rate of damage.

The tropical rain forest, the most fertile long established and biologically varied of all the worlds environments, is being destroyed at a rate of 29,000 square miles a year. That is an area the size of the whole of Scotland.

The land on the fringes of the Sahara is being so heavily overgrazed and plundered for its fire wood that in the Sudan for example the desert has advanced 60 miles in 15 years. As mankind allows his population to grow, cities are expanding and fertile fields lost at a rate according to one estimate by the UN, 25,000 square miles every year.

Malaysia has already launched her national policy on Biological diversity, one of many ways to protect its environment. The policy stresses among others that the biological resources must be managed in a sustainable manner.

Concerted research efforts are being undertaken to promote the sustainable production of quality herbal products in research institutes, universities, private enterprises and local herbal industries towards this end.

In addition they take action to ensure preservation of their unique biological heritage for the benefit of future generations through proper conservation.

In Switzerland the beautiful landscape and mountain ecosystem biodiversity is mostly conserved by the farmers. Through a series of political motions and referenda a consensus in agriculture policy in Switzerland is established.

In Sri Lanka IUCN sources state that about 50% of fresh water fish 61% of amphibians, 55% of reptiles, 27% of birds and 39% of mammals indigenous to Sri Lanka that were evaluated have been found to be threatened with extinction in the near or foreseeable future.

In addition 117 species of land snails including 52% of endemic species, 15 types of freshwater shrimps, 22 types of freshwater crabs, 70 species of dragon flies and 76 species of butterflies are also threatened in the country. Similarly over 700 species of flowering plants, are considered threatened.

As the land changes so species vanish. Biological believe that at least one in ten of every species of land living plants and animals could disappear within the lifetime of the majority of people alive today.

Destruction on such a scale would be even greater than that which over took the world 65 million years ago when the dinosaurs vanished. Whereas those extinctions took place over hundreds of thousands of years these will happen in decades.

A hundred years from now if things go on as they are no one will have any doubt as to the cause of the even greater and swifter mass extinctions that started in the last years of the 20th century. It was man himself.

The consequences of the mounting catastrophe are already afflicting humanity. According to a recent United Nations Environment programme survey one third of the surface of the earth is in danger of turning to desert and 470 million people living there.

More than one in ten of the world population are now seriously under nourished or actually starving. As the cover of natural vegetation shrinks so species of animals and plants are lost for ever. Yet we depend upon them for our food.

To maintain the immense productivity of our fields and so feed our overgrowing population we should cultivate carefully selected strains of domesticated plants.

As we use up the earths non renewable supplies of fossil organisms in the form of coal and oil so we will inevitably become more dependant not only for fuel but for organic chemicals on living plants and animals.

They given a chance would renew themselves but by then we will have destroyed a major proportion of them without even discovering what value they might have had for us. What is to be done?

A plan for the sensible treatment of the planet does exist. It is called the world conservation strategy and it rests on three propositions. They seem so obviously sensible that no one could ignore them. First we should not so over exploit natural populations of animals and plants that we prevent them from renewing themselves and so destroy them.

Second that we do not interfere with the large scale processes on which the stability and continued fertility of the world depends. Third and finally that we do our outmost to maintain the maximum biological diversity of the world. If we follow these the world environment at risk specially biodiversity depletion could be minimised.