Green House Gasses: a Bad Bunch Really or Just Getting a Bad Rap?

There seems to be a huge public outcry about the greenhouse gases and varied perceptions among general public and the environmental groups. However, before we attempt to evaluate the merits of “greenhouse gases”, let’s first clarify as to why these gases are called greenhouse gases.  The term “greenhouse” as we know it, is associated with an enclosure where the atmosphere is maintained under favorable conditions. Greenhouses are generally used for growing certain varieties of farm plants; vegetables & flower plants when outer environmental conditions are not favorable.  The system of a greenhouse depends on blocking the free exchange of air between the atmosphere inside the greenhouse and the outside environment. This structure generally made of glass panels or clear plastic material blocks or delays the normal transference of heat and energy between inside and outside environments. This allows the temperature to be maintained at a lukewarm level to avoid stress or death to the vegetables from excessive outside cooling. Scientists have named the theory “greenhouse effect” after the functional property of the greenhouse structure.

To further expand on this theory, greenhouse effect is an atmospheric heating phenomenon, caused on one hand, by short-wave solar radiation being transmitted inward through the earth’s atmosphere.  On the other hand, longer-wavelength heat radiation slowly transmitted outward, owing to its absorption by atmospheric gases. These gases; carbon dioxide, water vapor, ozone, nitrous oxide, methane, and others have been labeled by scientists as the greenhouse gases. Some of these are naturally present in the atmosphere and some are produced by human activity. Greenhouse gases that occur naturally are; Water vapors, Carbon dioxide, Methane, Nitrous Oxide and Ozone. Other categories of greenhouse gases like Hydroflorocarbons (HFCs), Perflorocarbons (PFCs) and Sulfur hexafluoride (SF6) result exclusively from human industrial processes and released in the atmosphere in varied volumes on daily basis.

 Although greenhouse gases make up only about 1 percent of the Earth’s atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet. Without this “warm air blanket”, planet earth would have become a frozen planet, essentially not suitable for any kind of life form or vegetation. However, just as the excess of any thing even the good one is some time bad; it is the excess of greenhouse gases that has become major concern for the environmental scientists. Essentially, life on earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into the space. The rest reaches the planet earth’s surface and then slowly reflected upward again as a type of energy that scientists call “infrared radiation”. As it rises, infrared radiation is absorbed by “greenhouse gases”, which slows down its escape from the atmosphere. This is the very process that on one hand makes the Earth a livable planet, but contributes to the problem of “global warming”, on the other hand.

 Greenhouse gases vary in their ability to absorb and hold heat in the atmosphere, By the way, HFCs and PFCs; the two categories that are exclusively generated as a result of human activity are the most heat-absorbent greenhouse gases. However, there are also wide differences between naturally occurring gases as for as their heat absorbency. For example, nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide, and methane absorbs 21 times more heat per molecule than carbon dioxide. Interestingly then, why scores of scientists and environmentalists are blaming carbon dioxide (CO2) for contributing to the problem of global warming? The answer lies not in its capacity to absorb the heat but in its ever increasing volume in the atmosphere.  Today more than ever before, human activity is adding significantly to the level of naturally occurring carbon dioxide. This gas is released into the atmosphere as a result of human activity on the individual level as well as through the industrial usage. Burning of solid waste, wood, oil, natural gas, coal and of course the automobile gasoline are some of the major contributing factors in this respect.  It is also important to understand that the two most heat absorbent gas families; HFCs and PFCs are getting a lot of attention by environmental groups. While these two categories have many good uses in the electronic, industrial and medical fields, they are also contributing significantly to the environmental damage when used as aerosol spray propellants and Styrofoam packaging.  Both these industrial uses are major contributors to the depletion of Ozone layer.  That in turn, causes human exposure to ultraviolet sun rays and the basis for skin cancer and other medical problems.

In summary, while greenhouse gases are the life giving bunch to planet earth and all living beings on it, the very same gases can threaten the fabric of life on this planet if we allow their volume to grow out of proportion. We will look at these gases and their properties; good and bad in more details later. We will also discuss life style changes of global citizens that can help maintain the volume of greenhouse gases at appropriate levels on the planet earth. We will talk about other interesting facts & myths surrounding greenhouse gases in an upcoming article.