GLOBAL WARMING

Global Warming: Its Causes And Effects

Global warming is a potential environmental problem. It can be defined as a steady increase in the global mean temperature which may result in the imbalance of environmental conditions. We know that the vital source of energy in the cosmos is the sun. The sunlight consists of light of different wavelengths such as Ultraviolet rays, visible rays and Infrared rays. Among those different rays, the Infrared radiations are responsible for the heating effect of sunlight. Due to that heating effect, life is possible on the earth. The sunlight manages the optimum temperature in the earth’s atmosphere so that life processes and other physical and chemical activities may continue effectively. However, the entire sunlight is not reached to the earth. Actually, when sunlight reaches the earth’s atmosphere, it is either reflected or absorbed by the clouds, earth’s surface and atmospheric gases. Only 50% of incoming solar radiations or sunlight reach the earth and warm it up for survival of living organisms.

Air which is the mixture of various gases contains some gases such as carbon dioxide, CFCs, ozone, methane, water vapour and nitrous oxide that allow solar radiations to pass through them but they absorb as well as partially reflect back the infrared radiations. Those gases are called Green House Gases (GHGs). GHGs are responsible for keeping the earth warm because they can retain the heat of the sunlight within their molecules. When these molecules of gases absorb heat from sunlight beyond their limit, they emit the heating rays like a red hot piece of iron and increase the temperature of the surroundings. Recently, their concentration has started rising and has resulted in increasing the mean global temperature. This increase in the temperature is termed as the global warming. During the past century, the temperature of the earth has increased by 0.6 °C. It is estimated that the average global temperature may increase by 1.4-5.8 °C by the year 2100. The gradual increase in the temperature of the environment can damage the entire living systems operating on the earth. Clearly, it is the GHGs which are chiefly responsible for the global warming. Hence, it would be better to check the increasing concentration of GHGs in order to sustain life and life processes on the earth.

There are several natural and man-made factors which are responsible for the global warming. Volcanic eruptions and forest fire are some of the important natural causes. But anthropogenic activities like deforestation, rapid urbanisation and industrialisation are more accountable for its intensification to a great extent. At present human population is budding rapidly. It has resulted in increased consumption of fossil fuels like coal and house hold fuels like firewood etc. We are now witnessing the faster technological changes and revolution in agriculture and transport sectors. No doubt, all over the world developments are taking places at the cost of environment. All these, along with several other human activities have been giving out substantial quantity of GHGs and the world is being left for facing the challenges of global warming.

Although one of the important GHGs i.e. Carbon dioxide gas is a comparatively insignificant non-pollutant gas in the atmosphere, its higher concentration is of grim environmental apprehension. As it is the most common GHG, its elimination or alteration is of prime importance. Nature has a mechanism for conversion of carbon dioxide gas into oxygen. Plants play the role of natural transducers here. They utilize carbon dioxides during the process of photosynthesis to make their own food and release oxygen gases as by-products. In this way, they keep up the delicate balance of carbon dioxide in ecosystems. But, deforestation due to the human needs results in the irregular rainfall, frequent floods, soil erosion, ground water reduction and increased drought condition. It also reduces the very utilization of carbon dioxide and augments its amount in the earth’s atmosphere. The more carbon dioxide means the more absorption of sunlight and the more chance of causing global warming.

Unfortunately, several anthropogenic activities are not eco-friendly and they pave the ways for consequences of global warming. Rise in global temperatures causes many climatic changes but most drastic change will be the increase in sea-level. A rise in sea levels is possible because of melting of ice from the poles due to the global warming. Melting even a fraction of the volume of polar ice can result in flooding of many low lying areas around the earth. The rise in global temperatures has already resulted in cracks in the Antarctic ice shelf.

Global warming is, therefore, of great concern and should be taken seriously. Every sphere of life is significantly affected from it. On the one hand, it has shifted the pattern of crop-yields and biodiversity at various levels around the world. On the other hand, it has badly damaged the quality and quantity of freshwater. It also causes natural disasters and climatic changes including storms, hurricanes, earthquakes, floods, droughts and exceptionally warm summers. The summer of 1998 predicted to be the warmest in the century.

The International Panel on Climate Changes (IPCC) predicts a shift in the current agricultural production pattern away from the current production areas to the northern latitudes. Changes in ground water availability, increased occurrence of climate extremes and crop diseases are also predicated. Europe and America have already witnessed these changes considerably. If this process of global warming persists, the continued existence of different floras and fauna including humans will be very distressing. The impact of the global warming process will be felt several sectors such as agriculture, fisheries, forestry and industries etc. This would ultimately affect the economies of any country. The damages caused due to the global warming are equivalent to that of nuclear wars as both have massive irreversible outcomes.

According to the report submitted to the United Nations Environmental Programme (UNEP) in February 2007, greenhouse gases are responsible for cold days, hotter nights, killer heat waves, floods and devastation and droughts. Global warming can alter some of the vital activities of living organisms such as metabolism, behaviours, reproduction and embryonic development. It will eventually lead to the death. Health experts expect a rise in climate related diseases such as heat strokes and spreading of vector borne diseases such as malaria into areas so far unaffected. Others have warned about the outcomes of increased water shortages and increasing pollution.

Global warming forms warm air and it will result in the cooling of upper atmosphere. Ultimately, It will disrupt radio-communications and further warm the troposphere. In other words, it will have effects on the range of species, food production, damage to property, ecosystems loss, primary sector damages, low output in agriculture, defects in fishery and forestry, quality and quantity of water, different means of transports, tourism industries, pollutions, migration of organisms and risk of disasters. It will not be exaggeration to say that Global warming is a real problem and this is the right time to act against.