Environmental Degradation and Management
The Tonga-archipelago and Key carals sites o coast Brazil. The prime minister of India announced a $50 million grant for biodiversity conservation in India and other developing countries under the Hyderabad pledge. The next conference of the parties (CoP) will be held in South Korea in 2014 in which the adverse effect of chemical fertilizers and pesticides in agriculture would be taken up. Identification of marine areas which are ecologically and biologically vulnerable was the main contribution of the Hyderabad Convention on Biodiversity 2012.
Environmental change is a continuous process that has been in operation since the earth came into existence about 4.6 billion years ago. Since then, dynamic systems of energy and material transfer have operated on a global scale to bring about gradual and sometimes catastrophic transformation of atmosphere, hydrosphere, lithosphere and biosphere. For most of the history of the earth, the agents of change have been the natural forces, like earthquakes, volcanoes, landslides, tsunamis, cyclones, droughts, floods and climatic change. But during the last few centuries, with the advances in science and technology, the environment has been changed by man beyond recognition. The impact of man on environment may be appreciated from the man beyond recognition. The impact of man on environment may be appreciated from the fact that during the last about 100 years, we have come equal to, or perhaps exceeded the powerful natural forces that for billion of years have shaped the biosphere and the face of our earth.
In fact, man has diverted and manipulated drainage systems, altered the quality of flow of water, brought forest areas under cultivation, modified terrestrial and coastal ecosystems to full his basic and higher needs. Though these changes were intended to produce improvements in society, but the results in many areas are quite opposite. Consequently, there are significant atmospheric changes which further resulted into problems of greenhouse gases, global warming, ozone depletion, acidification, salinization, soil erosion, desertification, problem of waste disposal, climatic change degradation of biodiversity and overall environmental degradation. The main causes of environmental degradation have been given briefly in the following:
1. Increase in Greenhouse Gases
One of the most important causes of environmental degradation and pollution is the burning of fossil fuel and industrial chemicals. The widespread use of fossil fuels began with the Industrial Revolution in Britain in 1779. The use of fossil fuels is increasing carbon dioxide concentration in the lower part of the atmosphere. Moreover, the emission of nitrous and sulfurous gases into the atmosphere is adversely affecting the ecosystems, ecology and biosphere. The main greenhouse gases that are adversely affecting the biosphere are:
(i) Carbon Monoxide
By volume, the greatest emission from human activity is carbon monoxide. It is a colourless, odorless, and tasteless gas. It is formed primarily by incomplete combustion of coal, fuel-oil, and gasoline. The largest single source is from the automobiles. The gas begins to affect the human body, leading to headaches and dizziness. Carbon monoxide has a residence time of several days. eventually, the carbon monoxide combines with oxygen to form carbon dioxide.
(ii) Sulphur Compounds
Sulphur dioxide is one of the major oxides of sulphur. Sulphur oxide (SO2) is the second most abundant pollutant. It is heavy, pungent, colorless gas. It forms from the combination of sulphur from emissions of coal burning industries and atmospheric oxygen. Sulphur dioxide is highly reactive and hence is not cumulative. The maximum residence time is probably 10 days.
Much of the compound combines with atmospheric water to form sulphuric acid. Atmospheric sulphuric acid causes the leaves of plants to turn yellow, it dissolves limestone and marble, and it is highly corrosive of iron and steel. It also reduces atmospheric visibility and blocks out sunlight. It is a major irritant to eyes and respiratory system and is lethal at a few parts per million.
(iii) Hydrogen Sulphide (H2S)
This is another sulphur compound that forms in the atmosphere. It forms from organic decay when there is not enough oxygen present to oxidize the organic material. The main source of hydrogen sulphide are swamps. It has very bad smell, like rotten eggs, but fortunately has a short residence time. In the atmosphere, it will darken lead in oil-based house paints. It is also responsible for tarnishing copper and silver.
(iv) Nitrogen Oxides
Nitrogen and oxygen do not normally interact at standard environmental temperatures. The substantial quantities of nitrogen oxide (NOx) results from combustion at high temperatures, largely automobile engines. Nitrogen dioxide (NO2) is the only widespread pollutant that has a colour to it. It is yellow-brown in colour and also has a pungent sweet odour. The average residence time is 3 days. The end product of nitric oxides is nitric acid (HNOx). Nitric acid is a major contributor to acid rain and surface ozone.
Written by princy