stated earlier, global warming is the rise in the degree of hotness of the
Earth’s surface. But the question is, what is the reason of the rise in this
temperature? How does the degree of hotness elevate without us knowing? Certainly,
we cannot see the process on how the temperature changes with naked eyes but
via deep understanding in Physics and other sciences, we can verbally explain
how this rise occurs. There are a few elements that encourage the increase in
the global temperature worldwide. The leading cause of this phenomenon is the
greenhouse effect is the process whereby the transition of infrared radiation
by gases within the environment warms its surface. In an easier way, greenhouse
effect is the impact of the presence of certain gases in the atmosphere. These
gases trap and accumulate heat and prevent the heat from escaping the
atmosphere. The gases that are being mentioned are such as carbon dioxide,
chlorofluorocarbon (CFC), methane, nitrous oxide and ozone. Most of these gases
occur naturally except CFCs. As more of these gases are present in the
surrounding, more heat will be trapped. As a result, the surrounding
temperature of the Earth will see an increase.
to answer what is a greenhouse, Figure 4.0.1 (a) has been attached in the
Appendices section, followed by how greenhouse effect takes place, Figure 4.0.1
(b). In actual, greenhouse is a method used to grow herbs, vegetables and
plants in a moderate climate, especially during cooler seasons, like winter.
This method of plantation is mostly famous in countries that experience four
different seasons throughout the year. A greenhouse is designed in such a way
that can aid in trapping and accumulating heat energy. Sunlight penetrates the
glass roof of a greenhouse in order to heat up the soil. Unfortunately, the
heat given off by the soil cannot pass through the glass roof and remains
trapped within the greenhouse system. This type of plantation is suitable for
agricultural activity of plants.
how does greenhouse effect raise the temperature of the Earth’s surface? When
sunlight penetrates and enters the Earth’s atmosphere, some solar radiation
escapes into space by reflection. However, the ratio of the radiation sent out,
into space is very little compared to the ratio of the radiation absorbed by
the Earth. The earth absorbs a lot of this radiation which warms the land as
well as the ocean. Once the Earth is warmed, heat in disguise of infrared
radiation will be emitted back into space. Unfortunately again, a lot of the
heat remains trapped by the greenhouse gases, which will heat up the
atmosphere. Meanwhile, the greenhouse gases causes the infrared rays to be
radiated back towards the surface of the Earth. This will increase the
concentration of greenhouse gases in the environment, such as carbon dioxide.
As discussed in section 3, an increase in the carbon dioxide level will
increase the surrounding temperature. Thus, this will lead to global warming.
Besides that, climate change or global warming is also
caused by the burning of fossil fuels. Burning of fossil fuels such as oil and
coals will emit a large concentration of carbon dioxide into the atmosphere.
Then again, the cycle continues where carbon dioxide causes an increase in the
global temperature. This then leads to global warming. Although this activity
does not occur at all parts of the world, it still affects the entire world
when there is a change in climate. For example, Australia is known for its
production of carbon dioxide gas. Production of electricity is one of the
reasons why Australia is able to produce a large amount of carbon dioxide. 73%
of Australia’s electricity originates from the burning of coal while 13% comes
from the burning of gas. The remaining fraction does not actually emit carbon
dioxide as it comes from renewable energy sources such as wind and solar.
Another undeniable cause of climate change is
deforestation as discussed in Section 3.0.3. Plants, trees and herbs have a
vital role in maintaining the temperature of the climate as it has the ability
to absorb carbon dioxide during photosynthesis. This way, it helps in the
maintenance of the carbon cycle. However, human activity such as deforestation
has disrupted the carbon cycle, causing a tremendous change in climate over the
past century. As the concentration of carbon dioxide increases, more heat will
be trapped in the atmosphere and this will lead to global warming.
To add on, farming also contributes in global warming.
Fertilizers used by farmers, mostly, contain nitrous dioxide, which is a
greenhouse effect. This gas will later accumulate around the atmosphere but it
will not be able to escape into space. Similarly, livestock organisms such as
pigs, calves and sheep have the ability to emit methane, which is also a type
of greenhouse gas. Nitrous dioxide and methane, being components of greenhouse
gases will then remain in the atmosphere and radiate heat as well as cause
global warming if the concentration increases. For instance, farming in
Australia releases 16% of their total greenhouse gas emissions.