Think green, live green!

We are now confronted with serios enviromental problems.The best way to fight them is by knowing what causes them and to figure out the best comprimise solution for the earth as well as for the humans.

Population growth

The major cause of most environmental problems is the rapidly growing human population, now at 6 billion (2000 estimate) people worldwide. A quarter of a million babies are born each day-90 million each year. In another 50 years, the population will grow to about 9-10 billion. Meeting the basic needs of all these people- food, housing, heat, energy, clothing, and consumer goods-places tremendous demands on the earth’s natural resources Without technological and land-use changes, in addition to population-control measures, the demands are bound to grow.Industrialized countries, with higher living standards and greater numbers of cars, produce far more air pollution and greenhouse gases than developing countries. Developed countries also contribute to overfishing and deforestation . But these countries can reduce serious environmental hazards by using technology such as smokestack scrubbers, emission systems, and waste-water treatment plants. Although developing countries consume a far smaller percentage of the world’s resources per person, the sheer numbers of people can quickly deplete soil, forests, and waterways.

Air pollution

Air pollution is one of the most pervasive enviromental problems because atmospheric currents can carry contaminated air to every part of the globe.Most of the air pollution gases come from vehicle motors and power plants that burn oil and coal to produce the energy needed for industry and consumer use.Carbon dioxide and other harmfull gases have a bad influence on our health and are also leading to the greenhouse effect.Sulf dioxide,nitrogen dioxide ,once pumped into the atmosphere will combine with clouds creating the acid rains.The ozone layer is also becoming thiner allowing the sun’s harmfull ultraviolette rases to reach the earth. That is why the global medium temperature is rising with about 1- 3 degrees celcius at every 50 years.Even if in the past 20 years the air quality has improved there is still allot to worry about.

wildlife and habitat destruction

According to some scientists, plant and animal species are becoming xtinct faster than at any time since the dinosaurs died out 65 million years ago at the end of the Cretaceous period. As of 1990, 12 per cent of mammals and 11 per cent of birds worldwide were classified as endangered or threatened. Throughout history, the primary cause of species extinction has been the introduction of non-native species into new ecosystems. Imported farm animals, predators brought in to control native pests, and accidental stowaways can severely harm native flora and fauna and upset ecological equilibrium. Habitat loss is the second most critical factor in species extinction. Worldwide, there is now 20 per cent less forest cover than existed 300 years ago, and there is five times as much land devoted to agriculture.

Forests and fields that are cleared for agriculture can sustain only a fraction of the species they formerly held.In recent years, conservationists concluded that it is ineffective to try saving species one at a time. Most efforts to preserve biodiversity now focus on the maintenance of the habitat necessary for plant and animal survival rather than on particular speciesTo that end, the World Conservation Union has set a goal of preserving 10 per cent of each of the earth’s major ecological regions by the year 2000, thereby protecting greater numbers of species from extinction.

Introduced species

In the course of transporting themselves and their goods, people have brought many other species along with them. Some they deliberately transplant from their native habitats to new and distant homes. Others they transport unknowingly. The result is a biological exchange so enormous that there are few environments on earth without some permanent residents that have been delivered there by people.Increasingly, concerned voices offer moral, aesthetic, and economic arguments against the introduction of foreign species. Education campaigns encourage people, businesses, and governments to prevent the inadvertent transport of foreign species, to control existing exotics, to restore degraded ecosystems, and to undertake any future introductions with the utmost care. Human welfare, after all, depends on preserving biodiversity. Through their mixing of species and disruption of ecosystems, human beings imperil themselves.

Desertification

Desertification is the process by which lands that lie at the margins of deserts are degraded and become deserts themselves. Desertification usually occurs due to overgrazing, poor farming techniques or deforestation . The removal of the natural vegetation exposes the soil to wind erosion

Soil erosion and exhaust

The main cause of soil erosion is deforestation.Deforestation occurs when forests are cleared or destroyed. It results in the loss of animal habitat , as well as increased soil erosion due to the loss of protective vegetation cover. In some areas, because the nutrient-deficient soil cannot support crops, a wasteland results within a few years.

Deforestation

Each year an estimated 170,000 square kilometres (66,000 square miles) of rain forest disappear, the equivalent of more than four times the area of Switzerland . At the current rate of destruction, the world’s lowland rain forests will have disappeared in 20 years’ time. Today, rain forests cover less than 8 per cent of the ‘earths surface, which is less than half of the area the rain forests covered when they were first exploitedWorldwide, there is 20 per cent to 33 per cent less tropical rain forest today than existed historically, with Brazil and Indonesia accounting for 45 per cent of the total loss.Rain forests are home to many groups of indigenous peoples such as the Penan of Borneo and the Kayapo of Brazil. A typical 10-square-kilometre (4-square-mile) tract contains more than 1,500 plant and tree species, 700 animal species, and thousands of insect types.

Consequently, destruction of large areas of rain forest can result in serious environmental problems, loss of habitat , and the extinction of indigenous cultures.On a global scale, deforestation damages the earth’s ability to clean the atmosphere . Rain forests and other large forested regions act as the planet’s lungs, converting carbon dioxide back into oxygen and filtering out pollutants. Scientists believe deforestation alters weather patterns and contributes to global warming, accounting for up to 25 per cent of the carbon dioxide released into the atmosphere each year.Many developed countries and international conservation groups have established debt-for-nature swaps,cancelling international loans in exchange for better protection of the earth’s critical forests.

Marine pollution and overfishing

Seventy per cent of the world’s population lives in coastal areas, and although coastal waters account for only about 0.5 per cent of all ocean water by volume, they provide habitat for half the world’s fish catch. As the number of people in coastal areas continues to rise, the potential for harming this habitat also grows.The causes of coastal habitat damage include deforestation, industrial chemical emissions, pesticide and fertilizer run-off, oil spills, sewage effluent, and overfishing. Half the world’s coastal mangrove forests, which provide critical spawning grounds for fish and help prevent erosion , have been cleared for firewood or artificial shrimp ponds. Coral reefs off the coastlines of numerous countries are in decline due to soil erosion from deforestation, sewage discharge, and industrial and agricultural chemical pollution.Many nations dump industrial waste products into coastal waters, both intentionally and as a by-product of routine practices. In fact, only 12 per cent of the oil that spills into the ocean results from tanker accidents.

The rest comes from land run-off, natural sources, and “normal” spillage associated with loading oil into tankers and cleaning out storage tanks while at sea. The Mediterranean Sea alone suffers the equivalent of 17 Exxon Valdez oil spills each year. The Valdez is the tanker ship that ran aground in Alaska’s Prince William Sound in 1989, spilling more than 39 million litres (10 million gallons) of oil into the water and on the shoreline .Fisheries around the globe are also showing signs of crisis. Internationally, overfishing has greatly depleted stocks of commercial fish species, and in the United States, catches for 85 per cent of commercial species, including cod, haddock, flounder, and wall-eye, are on the decline.

Anchovy fisheries off Chile and Peru are virtually unusable, and in some ecosystems , such as the Georges Bank off New England , native fish will never return to former levels because other species have taken over.Both individually and in group efforts, countries around the world are working to slow the damage to coastal marine habitat. Most cities in the United States, for example, have stopped throwing municipal wastes into the sea. And fishing nations have tentatively agreed to establish a polar whale sanctuary around Antarctica , a permanent refuge for a marine mammal that has been particularly hard hit by water pollution. As a conclusion to what we’ve discused:the earth is our only home we only have one chance .Let’s not waste it.

Bibliografy: 1998 Encarta World Atlas, Enviromental statistics.