The Greenhouse Effect

Global warming today is a burning environmental issue which is bothering environmentalists all around the world, and why not, it is an issue that tends to challenge the very existence of life on earth. Though few scientists think that global warming is not as important an issue as it is made out to be, they form a negligible minority. The term ‘greenhouse effect’, being in synonymous use with global warming has earned itself a bad name. However greenhouse effect is not as big a criminal as it is generally viewed as. On the contrary it is the phenomenon which sustains life on earth by maintaining just the right temperature.


The term ‘greenhouse effect’ is derived from the working model of a greenhouse which is used in cold countries to facilitate plants with sunlight for their survival. Greenhouses employ walls and roofs made of glass which has a unique property with regard to passage of sunlight. It allows sunlight to pass through it into a closed area and traps it within the closed area of the greenhouse for the benefit of the plants.


Similarly the carbon dioxide, water vapour and methane (collectively called greenhouse gases) form the ‘glass’ in the huge greenhouse called ‘atmosphere’. About thirty percent of total solar radiation is reflected back into space by the earth’s atmosphere. Of the remaining that penetrates the atmosphere, 45% is absorbed by the earth’s surface and 25% is absorbed by the atmosphere. Thus the atmosphere is made warmer and makes life on earth possible. This is called the greenhouse effect. If these gases did not trap heat, the earth’s temperature would have been about thirty degrees Celsius lower, making survival doubtful.


Then why is ‘greenhouse effect’ termed as responsible for global warming? When the quantum of the greenhouse gases in the atmosphere increases, the heat trapped by it becomes higher. The resultant unnatural rise in the earth’s temperature is the phenomenon we all know as global warming. Still, greenhouse gases are not the ones to be blamed. The increase in the density of these gases is solely due to human activities, its effects on environment making them inhuman in nature. However it is not only Mother Nature that is being harmed; the inextricably related homo sapiens too are at the receiving end of the wrath of their own activities.


Everyday life of an average human adds considerable fuel to the fire of global warming. The very act of exhaling adds carbon dioxide to the atmosphere, the population explosion only multiplying its density. Combustion of fossil fuels gives out, in addition to light and heat energy, water vapour, carbon monoxide and carbon dioxide among other gases. This process is a part of the working of power plants using coal and the vehicles on road, water and air. While these are the direct sources of excess production and emission of greenhouse gases, excessive demand for electricity puts pressure on the power plants to produce more thus indirectly adding to CO2 emissions.


On the large scale, global warming causes melting of glaciers leading to a rise in the global sea level. This, in turn, causes the submergence of low-lying coastal areas under sea water. This would also cause flooding of rivers reducing the earth’s reserve of freshwater. In regions where water is already scanty, large areas would come under drought and land will become unsuitable for vegetation. At the very basic level, the rise in temperature will cause diseases like malaria to thrive, because vector-borne diseases widen their range under warmer climate. Moreover, endangered species might become extinct under the unnatural rise of temperature.


There are many international and national level steps that can be taken if governments and industries decide to collaborate and work towards stopping a future catastrophe; for example producing and putting to use more efficient power plants and eco friendly vehicles. As a group of people the steps that a community can execute towards lesser emission of greenhouse gases include car pooling and planting trees. Even on an individual level we can play our part in reducing the amount we pollute our environment. In order to reduce the consumption of electricity, one can be cautious enough to switch off electrical appliances whenever not in use, replace light bulbs with energy efficient CFL and use air-conditioning and heating in moderation. While it might not be feasible to walk or cycle to our workplace, school or college, one can surely consider the option of public transport.


Since freshwater scarcity is an effect of global warming, one must make attempts to save water too. Bathing out of a bucket than taking a shower saves much water (and reduces hair fall too); water used for washing vegetables can be reused for watering plants. At the community level, rainwater harvesting helps to replenish the underground water-table level.


Trees being an excellent source of oxygen and an effective absorber of carbon dioxide, it is only rightful that we take steps towards conservation of trees in our own small way by not wasting paper and using recycled paper. Though it might not be possible to grow trees in our balconies, small plants can help to make our immediate environment greener and fresher.


It is high time we stop flaunting money by keeping televisions, computers and air conditioners switched on all day, or thinking that not driving a personal car to office is low key. One might excuse himself by saying he has the means to finance himself, but let’s just stop and think: if there is no electricity after five years nor petrol after ten, what can your money do for you?


We do not own this world. We are just keepers of this earth before we hand it over to the next generation, like our ancestors were for us. Thus we cannot live life king’s size without thinking about the future. Similar to the assumptions that dinosaurs got extinct because of climate change, one day man might fall prey to the same change. “Officially announcing the extinction of the human race, known for its much praised intelligence, but which could not save him from his own slow destruction.”


Deepa Sebastian

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