Global warming (1)

Effects of global warming

The increment in carbon dioxide concentration in the atmosphere is one of the indubitably serious environmental concern. The atmosphere consists of methane, chlorofluorohydrocarbons, nitrous oxide, water vapour and carbon dioxide, which leads to global warming. Statistics from Indian Institute of Technology Madras shows that carbon dioxide contributes to 50% of the world's temperature rise, while the gas succeeding it, methane, or CH4, only contributes to 19% of the world's rise in temperature.

Chlorofluorocarbons, nitrous oxide, CO2 and methane has been significantly increasing each year, however, the largest effect of global warming is still due to CO2. Anthropogenic production of CO2 from burning fossil fuels exceeds that of the other greenhouse gases. Even though the concentration of CO2 in the atmosphere in the natural state due to the constant respiration of the biosphere is much greater, this flux is in balance with photosynthesis. CO2 exist in the atmosphere naturally to trap heat so that the warmth of the Earth is maintained for animal's survival. CO2, hence, is also known as a type of greenhouse gas.


Greenhouse gases trap solar energy and keep Earth warm. Greenhouse effect is this natural phenomenon of warming Earth’s surface and lower atmosphere whereby gases in the atmosphere trap heat from the Sun's rays to keep Earth warm.  Some of the rays that pass through the atmosphere are reflected back into outer space when they reach Earth.  However, gases in the atmosphere trap some of the reflected heat from these rays just like glass panes of a greenhouse. As such, Earth is kept warm enough at about 15 degrees Celsius for life to exist. On the other hand, without Greenhouse Effect, heat from the Sun would be lost to outer space and Earth would be approximately 33 degrees Celsius lower, which is too cold to support life. Greenhouse effect in its natural state is ideal because greenhouse gases occur naturally, trapping solar energy and keeping Earth desirably warm to sustain life.

However, an excess of it would mean an increasing Earth temperature, also known as the Enhanced Greenhouse Effect or Intensified Greenhouse Effect. It is a process whereby excessive heat from the Sun is being trapped by atmospheric gases due to an increase in the amount of greenhouse gases as a result of human activities. This excessive trapping of solar energy leads to an increase in average temperature of the Earth's surface known as Global Warming. It is estimated that Earth's temperature has increased by about 0.3 degrees Celsius in the last 40 years.If left unchecked, Earth's average temperatures will rise a further 1.5 to 4.5 degrees Celsius in the next 100 years.

Since the Industrial Revolution in the 1700’s, human activities, such as the burning of oil, coal and gas, and deforestation, have increased CO2 concentrations in the atmosphere. In 2005, global atmospheric concentrations of CO2 were 35% higher than they were before the Industrial Revolution.Carbon dioxide (CO2) concentrations in the atmosphere increased from approximately 280 parts per million (ppm) in pre-industrial times to 382 ppm in 2006 according to the National Oceanic and Atmospheric Administration's (NOAA) Earth Systems Research Laboratory, a 36 percent increase. Almost all of the increase is due to human activities. The current rate of increase in CO2 concentrations is about 1.9 ppmv/year. Present CO2 concentrations are higher than any time in at least the last 650,000 years.

Causes of Global Warming

The expansion of agricultural activities is one of the human causes of global warming. Carbon dioxide is absorbed by plants during photosynthesis process. If natural environment is left untouched, optimum level of carbon dioxide remains. However, increase in agricultural activities makes it necessary to create more space through deforestation. Deforestation by burning releases carbon dioxide in the atmosphere. This is worsened by the presence of fewer trees to use up and remove excess carbon dioxide from the atmosphere. This problem is especially prevalent in the Indonesia area, where many environmental officials are actually involved in illegal logging and hurting its own forest.

Another gas that cause global warming, as mentioned, is methane. Methane is produced in wet rice cultivation because flooded fields are ideal for methane-releasing bacteria to thrive, such as Rice Paddies in Japan. In livestock farms when sheep and cattle digest and belch, like cattle manure in México, and where organic waste matter and decayed vegetation decomposes, methane is too, released into the atmosphere.

Furthermore, as the human population increases, more food is needed. More nitrogen-based fertilisers are used to increase crop yields. Nitrous oxide is emitted, increasing the amount of greenhouse gases. For example, cropland soils in China are turning acid from the overuse of nitrogen fertilisers, decreasing productivity, polluting the environment, and contributing huge amounts of greenhouse gas emissions. 

In addition, there is the industrial development and expansion of manufacturing industries. With industrial development, more fossil fuels are burnt in power stations and factories to cater to increasing demands for energy to run machinery, resulting in more carbon dioxide emitted. Since Singapore started her development toward a first-world country, CO₂ emissions has increased about 83% from 1990 to 2007. Next up, the use of solvents in industries and making of foam packaging release CFCs. Also, rising affluence results to increase in private car ownership. As society gets richer, private cars become affordable and people tend to drive instead of taking public transport. More nitrous oxide is released from vehicle exhausts.

Chlorofluorocarbons (CFCs) are also effective in trapping heat, with one molecule of CFC having the ability to trap as much heat as the ability of 10 000 molecules of carbon dioxide. CFCs are released through the use of aerosol sprays which act as propellant that releases CFCs, and careless and inconsiderate disposal of old refrigerators and air conditioners, where the CFCs are used as coolants.

Last but not least, the lifestyle changes and indifferent attitude of people are of paramount importance in today's warming world.