The Greenhouse Effect Essay

This essay has a total of 2221 words and 11 pages.

The Greenhouse Effect








The Greenhouse Effect



















Issue Statement

While some people believe the earth's climatic changes are due to the fact that the
universe is getting older, others believe it is due to the greenhouse effect.


The greenhouse effect is a naturally occuring phenomenon that is responsible for
trapping heat near the earth's surface and keeping the planet warm. It is called the
greenhouse effect because the way it works is similar to the way in which a green house
functions. In a greenhouse sunlight passes through the transparent roof and walls and
strikes the objects inside- plants, flowerpots, tables, and so forth. These objects
absorb energy from sun, become warmer, and then give off energy themselves in the form of
heat. Only a little of this heat energy passes out through the glass, much of it is
"trapped" in the greenhouse, raising the temperature inside.

In some ways, the earth functions rather like a greenhouse except on a much larger scale.
Although the greenhouse effect has only recently been in the news, is nothing new in th
history of our planet, has played major role in making life on earth possible. Without the
greenhouse effect, the earth would be too cold for living thing to survive. The big
question today is "If greenhouse effect is natural, why are people so worried about it. Is
soemthing good turning bad?" Up until about 150 years ago the compostion of the earths
atmosphere had remianed relatively unchanged for several thousand years. Since mid 1800s
certain human activities have been changing the heat trappin ability of the atmospher
dramatically, as a result more heat is being trapped by the atmosphere. Scientists have
been anticipating this "strengthening" of the greenhouse effect for sometime, and that it
will lead to a worldwide increase in temperature. This is come true because the world is
getting warmer. Global warming can be expected to change the earth's climate dramatically
and in a relatively short time. As temperatures increase, experts predict that weather
patterns will be disrupted worldwide, the glaciers and polar ice caps will, melt, and that
sea levels will rise. Global warming could change the atmosphere so much and so fast that
all sorts of plants and animals might soon be in danger os extinction. The greenhouse
effect may be the most serious environmental problem the human race has ever experienced,
for this reason scientists around the world are working hard to acheive a better
understanding of the greenhouse effect, to predict the impact it will have on earth, and
to discover ways to control it.

The greenhouse effect occurs when gases such as methane, carbon dioxide, nitrogen oxide
and CFCS trap heat in the atmosphere by acting as a pane of glass in a car. The ‘glass'
lets the sunlight in to make heat, but when the heat tries to escape, the gases reabsorb
it. Holding this heat in causes heat waves, droughts and climatic changes which could
alter our way of living. The greenhouse effect, in environmental science, is a popular
term for the effect that certain variable constituents of the Earth's lower atmosphere
have on surface temperatures. "It has been known since 1896 that the Earth has been
warmed by a blanket of gases. The gases; water vapour (H2O), carbon dioxide (CO2), and
methane (CH4) keep ground temperatures at a global average of about 15 degrees C."
(Oppenheimer, p. 119-120) Without them, the average would be below the freezing point of
water. The gases have this effect because as incoming solar radiation strikes the
surface, the surface gives off infrared radiation, or heat, that the gases trap and keep
near ground level. Environmental scientists are concerned that changes in the variable
contents of the atmosphere, particularly changes caused by human activities, could cause
the Earth's surface to warm up to a dangerous degree. "Since 1850 there has been a mean
rise in global temperature of approximately 1 degree C." (Gribbin, p. 14) Even a limited
rise in average surface temperature might lead to at least partial melting of the polar
icecaps and hence a major rise in sea level, along with other severe environmental
disturbances.

What is meant by the term, the greenhouse effect, is that the heat from the sun comes into
the Earth's atmosphere and cannot get out so it becomes trapped. This effect occurs when
the incoming short wave radiation hits the Earth's surface it changes into longwave, or
infrared radiation. Heat energy in this form is then absorbed and stored in water vapour
and carbon dioxide in the atmosphere.

The main gases that cause the greenhouse effect are water vapour, carbon dioxide (CO2),
and methane which comes mainly from animal manure. Other gases like nitrogen oxide and
man made gases called chlorofluorocarbons get caught in the atmosphere as well. The decay
of animals and respiration are two main but natural sources of carbon dioxide.

Water vapour is an important "greenhouse gas". It is a major reason why humid regions
experience less cooling at night than do dry regions. However, variations in the
atmosphere's carbon dioxide content are what have played a major role in past climatic
changes. In recent decades there has been a global increase in atmospheric carbon
dioxide, largely as a result of the burning of fossil fuels. If the many other
determinants of the Earth's present global climate remain more or less constant, the
carbon dioxide increase should raise the average temperature at the Earth's surface. As
the atmosphere warmed, the amount of water vapour would probably also increase, because
warm air can contain more water than cooler air. This process might go on indefinitely.
On the other hand, reverse processes could develop, such as increased cloud cover and
increased absorption of carbon dioxide by phytoplankton in the ocean. These would be
natural feedbacks, lowering temperatures.

Many different things cause The greenhouse effect. "The amount of carbon dioxide in the
atmosphere is increased by 0.4 percent each year because of the massive consumption of
Continues for 6 more pages >>