Everyday, we are comforted by the warmth of the sun, we feel its heat radiating specially at high noon. At night, the sun sets but we can still feel its effects. How is this possible?
The visible light radiated by the sun is converted into heat energy by different objects around us. Some of the heat is radiated back to space in the form of infrared radiation. However, most of it remains in the atmosphere. This is because the atmosphere has some gaseous components that serve as a blanker that effectively absorbs heat and reflects it back to Earth.
These components are known as greenhouse. Some examples of greenhouse gases are water vapor, carbon dioxide (CO2), ozone (O3), nitrous oxide (N2O), methane (CH4), sulfur hexafluoride (SF6) and chlorofluorocarbons (CFCs). These gases help deep the temperature of Earth at an optimum even at night.
Warmer and warmer
In the course of time however, the average temperature of Earth has significantly increased. This brought forward the issue of global warming. Researches found that this phenomenon is due to the increase in the concentration of greenhouse gases in the atmosphere.
Aside from their concentration, the gases’ ability to absorb infrared radiation is also taken in to account. For instance, CFCs are found in very low concentrations but are 15000 times more effective in absorbing heat. CO2, on the other hand, has a relatively large concentration but is not as effective in heat absorption.
The greenhouse gases
· Carbon dioxide. Over the years, the amount of CO2 has increase due to many factors. One of which is the constant burning of fossil fuels used to produce electricity and ran cars. CO2 is produced by burning hydrocarbon in the presence of oxygen.
Overpopulation is another cause. More people mean more CO2 is released through respiration. This could be addressed, at least partially, by growing more plants. Green plants undergo photosynthesis – a process wherein CO2 us used together with water to produce sugar and oxygen.
· Methane. A natural gas mostly produced in wetlands when vegetation decays without oxygen. Fossil fuels and livestock are also principal sources. Methane has a very small concentration in the atmosphere compared to CO2 but is more efficient in absorbing heat.
· Nitrous oxides. Produced from fertilizers and the burning of fossil fuels, these compounds are also efficient in trapping the heat of the sun. They have a lifespan of around 230 years in the atmosphere and therefore tend to accumulate over time.
· CFCs. Although the CFCs released in the atmosphere are relatively low compared to other greenhouse gases, they are very efficient in trapping the heat from the sun. Most of the CFCs in the atmosphere came from refrigerants and solvents. Although CFCs are no longer used these days, their presence is still notable because they do not readily decompose.
To eliminate and control
The increase in the amount of greenhouse gases can be controlled through various means. One of which is planting more trees to absorb more carbon dioxide.
Burning less fossil fuel would also help and this would lessen the production of CO2 and nitrous oxides. Cars can use catalytic converters to prevent the release of nitrous oxides from their exhausts. Catalytic converters break down nitrous oxides into nitrogen and oxygen.
The search for alternative and more Earth-friendly energy sources should also be pursued. Similar researches should also be done for compounds such as refrigerants and solvents.
The effects of global warming
The scientific community is divided on the effects of global warming. One group says that it is the natural course of things and that people and other species could adapt to the changing temperature.
On the other hand, the opposing side believes that global warming would bring about the melting of glaciers and the polar ice caps. As a result, some areas will be heavily flooded while others will be completely erased from the map.
Extreme climate changes such as heavy rains and droughts are also expected, these can bring about the migration of people leading to the overpopulation of some areas. Famine can also occur due to these and the possible damage to agricultural crops.
Wherever this issue will lead us, man should be ready about its possible consequences and the actions he should take regarding it.
By Maricar Ribo-Ramos
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