Greenhouse Effect

Written By Admin
Dated: March 26, 2007

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Global warming is the term which has come to describe the effective increase of Earth’s average temperature on the surface and its projected continuation. There is currently a lot of controversy surrounding the issue, but there are important factors to be taken into consideration -  many of which are up for debate.

The ‘greenhouse effect’ is a theory on why the Earth is showing a steady increase in temperature.  It should be noted that there is no actual relation to the analogy of an actual greenhouse - as the effects are somewhat similar, but different. This effect is essentially believed to be caused by gases expended by humans, such as methane and carbon dioxide.  In this process, the Sun radiates energy onto Earth, which bounces 30% of the energy off - but absorbs the other 70%.  While some of the thermal energy is radiated back into space, much more gets ‘trapped’ by the greenhouse effect.  Infrared radiation trying to escape is instead absorbed by greenhouse gases and re-emitted into the atmosphere.  This in turn warms the surface of the earth about 30 degrees Celsius more than it would be without the effect - making it vital to human survival.  Without it, Earth would be much less capable of supporting current known forms of life.  Even still, the recent increases are threatening to disrupt the balance - and possibly create a new climate altogether.  This balance is extremely fragile since changes in the greenhouse effect can be hard to maintain.  Gases like methane or carbon monoxide, which add to the effect, are emitted by everyday objects such as cars or factories.  Many regulations exist currently, but some can’t be avoided.  Fossil fuel energy sources are used around the globe, making greenhouse gas much harder to stabilize or maintain.

Greenhouse gases have been widely thought to be the problem in global warming.  Many say that without the emissions from man-made objects, global warming wouldn’t be a problem.  Some say a climate change will eventually occur and a climate like the one we have now, only much warmer or colder, depending on your side of the debate.  This change can come through ‘climate forcing’, or the act of forcing the global climate to change from global energy balances being disrupted.  This can be seen in history, as Earth has gone from Ice Ages to warmer climates, like the current one experienced today. Climate forcing is generally known as something to fear as many major climate changes have resulted in minor to massive extinctions of many species.

 Events like the Permian-Triassic extinction have made some researchers come to worry about Earth’s present situation.  This extinction occurred about 251 million years ago, and was responsible for over 96% of all marine life becoming extinct.  It is believed this event was caused by the release of methane underneath sea beds - a direct result of global warming.  Even more alarming, is the fact that such methane exists under the Siberian tundra, and if released would cloud the atmosphere and become a deadly greenhouse gas, about 21 more times as powerful as the effects of carbon dioxide.  It is believed this extinction was caused by what is called the runaway effect.  This theory claims that if you had greenhouse gas A increase in temperature, greenhouse gas B also increases in temperature.  With an unlimited supply of gas, this would effectively continue until all of Earth was extinct.  Luckily, there isn’t enough gas to produce a permanent runaway effect, but it exists nevertheless and describes the actual ‘stopping’ of the temperature increase after the gases have stopped providing feedback to each other.

The ozone layer, comprised of O3, is vital for the human race to survive.  This layer effectively takes out harmful ultraviolet light rays, or UV for short.  This radiation is emitted from the sun and is partially absorbed by the ozone layer.  This is extremely important, as the UV rays can cause serious genetic damage to all living organisms.  This is the main cause for sunburns and more serious illnesses such as skin cancer.  Naturally, the ozone layer is extremely important to maintain.  However, it is actually being steadily depleted, a threat to many forms of life on Earth.  The depletion is believed to be a result of chlorofluorocarbons or CFC, for short.  These CFC’s are also a direct result of human activity, much like the methane in global warming.  These CFC’s effectively catalyze a chain reaction when released into the ozone layer and break down the ozone molecules. Because of this, there are major ‘holes’ in the ozone layer, where damage has been done. Thankfully, a global regulation was formed to help stop CFC use, most commonly from aerosol sprays.  The past decade has shown a substantial decrease in damage to the ozone layer.

Global warming and the greenhouse effect are closely related.  The fear of an uncontrollable climate change has led governments to find a solution.  A delay of merely 20 years in taking action would see a lot of damage to the Earth’s current climate, meaning action should be taken as soon as possible.  Leaders and scientists around the world have begun talking about alternative energy sources and reduction of emissions, both of which are in dire need.  Governments such as the United Kingdom’s have put bills in effect to reduce emissions by around three quarters of the current levels by the year 2050.  Even still, many do not believe we have the time to wait this long as some species are in danger of becoming extinct in the current climate.  Other solutions have faster effects, with alternative fuel sources being the primary goal.  Many worry that if something isn’t done soon enough, Earth as we know it will change for good.  It is estimated that Earth’s average temperature could rise by as much as 30 degrees Fahrenheit in 50 years, an alarming figure.  Such statistics and facts have proved the that existence of global warming is fast becoming a threat to human survival.