GLOBAL WARMING: THE RISING TEMPERATURE OF THE EARTH
The age old proverb everybody talks of weather but nobody does anything about it is not valid in this century. A world wide study shows that average temperature of the earth has risen by as much as 0.2 °C every decade. The rise in temperature is due to global warming which has now become an imminent threat.
Our earth today absorbs large quantity of solar energy from the sun. Most of this energy is radiated back to the atmosphere by the earth, and this process maintains the balance of heat and energy on the earth. There are many gases present in the atmosphere, but only carbon dioxide and water vapour absorb this infrared radiation of the earth strongly and effectively block the radiation of energy back to the atmosphere. However a” considerable part of it is remitted to the earth’s surface and consequently the earth’s surface gets heated up. This increase in temperature of the earth is called the Green house effect.
The temperature effects carbon-dioxide and water vapour combine together to have a long range impact on the global climate, as the surface temperature increases, the evaporation of surface water increases thereby raising the temperature further. It is estimated that this combined effect of rise of temperature will bring about 30°C rise in surface temperature if the carbon dioxide concentration is doubled in the atmosphere. The most alarming fact is that a slight increase in surface temperature say around 1 °C can adversely affect the world of food production. As a result the wheat growing zones in the northern latitude will be shifted from USSR and Canada to the north poles that means from the fertile soils to the poor soils. The biological productivity will also decrease due to warming of the surface layer, which in turn reduces the transport of nutrients from deeper layers to the surface.
Carbon dioxide gas although a relatively insignificant pollutant gas in the atmosphere, is a serious environmental concern. It has the potential to be compared with the nuclear wars in terms of massive irreversible damage to the environment. Increase of carbon-dioxide gas in the atmosphere is constantly occurring. Volcanic eruptions and forest fire are some of the natural cause which cannot be checked. But the current global trend in deforestation along with increased combustion of fossil fuels, have a cumulative effect on the net increase in carbon-dioxide content forests are the areas where the green leaves efficiently carbon-dioxide to make their own food. Deforestation reduces this utilization of carbon-dioxide consumption of fossil fuels and household fuels like coal firewood also gives off considerable amount of carbon dioxide.
Rising is global temperature cause many climate changes also but the most drastic change will increase in sea level. Already, the rise in global temperature has resulted in cracks in the Antarctic ice shelf.
Melting of even a fraction of the volume of polar ice can result on flooding of many low lying areas around the earth. Other climate changes include floods, droughts, storms and exceptionally warm summers. Europe and America have already experienced this to considerable extent. The summer of 1998 predicted to be the warmest in the country.
Prevention is always better man cure. Human contribution and efforts can certainly prevent and control this global warming. It can best be carried but by checking atmospheric pollution. Deforestation should be stopped. Wood should be used as little as possible because wood maintains vast reservoir of fixed but readily oxidizable carbon. Bricks houses should be encouraged as they retain less heat. Thus they are well suited to Indian climate.
Unnecessary combustion of fuel should be checked. In houses, combustion of fuels like wood, kerosene should be controlled. Instead IPG, stove should be used which results in greater efficiency in fuel utilization and less atmospheric pollution. Encouraging biogas plants in village communities has many fold effects. It decreases the use of firewood, is less atmosphere pollutant and is a by-production of manure. Development of more efficient vehicles would also result in less consumption of fuel and therefore less atmospheric pollution.
Renewable sources of energy should be used as it is non polluting and very efficient. The renewable sources of energy are solar energy and wind energy. Hydroelectricity is also of considerable use. Lastly treatment appliances should be applied on the source of greenhouse, gases which are carbon dioxide and methane so that they may not violate the atmospheric balance.