Global warming is the increase in the average temperature of the Earth’s surface due to the effects of greenhouse gases. These greenhouse gases for instance, carbon dioxide resulting from burning fuels or from deforestation trap heat that would otherwise escape the surface the earth surface. There is no universal definition of global warming. However, the Natural Resources Defense Council (NRDC) defines it as any rise in the regular temperature of the earth surface. It also notes that the increase may be because of natural occurrences within the earth’s atmosphere or by man made influences. Houghton (2006, p 18) argues that the major cause of global warming is the emission of carbon dioxide. Since carbon dioxide is a good absorber of radiations from the surface of the earth it acts like a blanket over the earth surface hence the increase in temperatures. The rise in temperature results into a subsequent rise in the quantities of water vapor in the earth’s atmosphere which provides further blanketing .The predicted results of global warming include a rise in sea levels, changes in weather patterns (rainfall patterns), increased likelihood of extreme events like flooding and hurricanes, loss of biodiversity and spread of diseases like malaria as a result of change in weather patterns.
Causes of Global Warming
Global warming may be caused by natural and human factors. Both factors result into an increase in the levels of greenhouse gases. Some of the naturally occurring greenhouse gases are methane, carbon dioxide, water vapour, ozone and nitrous oxide which together form a blanket effect on the earth’s surface. These gases regulate the temperature of the earth surface when their levels are maintained. Any imbalances in their levels result into changes in global temperatures. Pollution is one of the human activities that may lead to global warming (Maslin 2006, p 12). Scientific research has shown that there has been a considerate increase in levels of atmospheric carbon dioxide since the start of the Industrial Revolution. Maslin (2006, p 12) continues to say that since 1958, there has been an annual increase in the levels of atmospheric carbon dioxide. He asserts that the average concentration of approximately 316 parts per million by volume (ppmv) in 1958 increased to nearly 367 ppmv in 1998. Melts (2010, p 7) confirms this when he says that there are a lot of green house gases emitted into the atmosphere of the earth which trap heat radiations. Such emissions from industries, cars and power stations produce more greenhouse gases into the atmosphere.
Deforestation which is the conversion of forested areas to non-forest land or the general degradation of forests is also a cause of global warming. Forests can extract carbon dioxide and other pollutants from the atmosphere. Research has shown that tropical deforestation contributes 90% of the present total biotic carbon dioxide released into the air. The accumulation of carbon dioxide as a result of burning of timber or leaving timber to rot is a cause of rise in the global temperature. Forests also act as carbon absorbers through photosynthesis and through this process the level of this gas is reduced.
Naturally, there may also be an increase in global temperature due to the trapping of the long wave infra red radiations by green house gases. During the heating of the earth, on average about one third of the solar radiations is reflected back to space while the rest are absorbed by the earth itself. The warming of the earth results into the emissions of infra red radiations which may be trapped by the naturally occurring green house gases.
Consequences of Global Warming
Global warming is a general concern of nearly everybody. The global temperature trend has recorded an increase since the 19th century. Saliken et al (2009) argue that this warming trend over the last 50 years has doubled compared to that of the last century (p. 50). The global average surface temperature is expected to be between 1.8 0C and 4.0 0C higher at the end of the 21st Century. This increase would result into loss in biodiversity (Metz 2010, p. 5). The other effects include the rise in sea levels which may affect low-lying cities and islands with sea water, variations in rainfall patterns resulting into droughts and fires, flooding, melting of icecaps, loss of habitat, and spread of diseases due to changes in weather patterns.
In order to check on global warming a legally binding agreement between signed up countries was made. This agreement was referred to as Kyoto Agreement and targeted to achieve emissions reduction targets of all greenhouse gases by 2012 relative to 1990 levels. As at August 2011 , 119 countries and one super national Union, the European Union, had signed and ratified the agreement with a general overall emission target of 5.6% .This agreement is effective since countries that were responsible for 55% of 1990 emissions like Russia have already ratified the agreement and other eco-advanced countries have agreed to high emissions targets .It also set penalties, review annual meetings and embraced a market based approach to offer incentives to members finding it expensive to achieve emissions reduction. Some people vie this agreement as an expensive agreement aimed at achieving little emissions reductions thus may not succeed in obtaining its set targets. However this view may not hold water due to the increase in signing and ratification of the protocol by countries and unions.
Myths about Global Warming
There are also some scientists who do not believe in global warming. A number of myths have been proposed to support this argument. Victor (2011, p 5) explains the scientific myth that argues that scientists are able to determine the safe level of global warming. He expounds that once this level has been set then the society optimizes to achieve that goal which is a myth since no one knows how much warming is safe. Others also argue that the global temperatures are rising at a rapid rate which is untrue since this argument has not been experimentally recorded from the recent satellite, balloon and mountain top observations made in the recent past.
Some scientists argue that the global warming is caused by the earth recovering from the Mini Ice Age (1350 AD- 1850 AD) (Page 2007, p. 3). They say that this was a period of cold conditions. This argument assumes that the earth has some natural temperature to which it always return which is untrue. Again, the climate of the earth may have remained that way or even gotten colder if the assertion is to be believed.
This paper has shown that global warming is real. It has listed the causes of global warming as pollution, deforestation and the natural causes which result from the heating of the surface of the earth. The effects of global warming which includes melting glaciers as a result of the warming of the planet, erotic weather patterns, health issues and the loss in habitat have also been discussed. The prediction of scientists on the future effects of global warming if it goes unchecked has also been considered. In fact, if the current rate continues then more than a million species of habitat could become extinct by the year 2050. However, some of these consequences have already been felt like the melting of glaciers, hurricanes, change in weather patterns and flooding and even the emergence of new infections and spread of others like malaria and asthma to new zones.