FREE ESSAY ON GLOBAL WARMING

GLOBAL WARMING

Greenhouse gases (chlorofluorocarbons, carbon dioxide, methane, nitrous oxide, etc.)let
heat in but stop it from going back out - like a windshield in a parked car.
At our current rate of creating these gases by industry, cars and burning fossil fuels,
scientists predict a temperature increase of 4 to 9 degrees F by 2050. (9 degrees F
separates today's average temperatures from the last ice age.)
The United Nations Panel on Climate Change recommends that we immediately cut our use of
fossil fuels by at least half. To prevent the current rate from increasing, we would have
to cut by 60%.
This same panel projects that by 2050 over a million more people dying each year from
malaria because of higher mosquito populations due to global warming. Already yellow and
dengue fever bearing mosquitoes are found over 3000' higher than their normal range in
South America.
Other predicted results of global warming include expanding deserts, forest fires, heat
waves, crop failure, erosion, mud slides, mass extinction of plants and animals, sea
level increases causing flooding and damage to coastal aquifers.
The US with c. 5% of the world's population creates 25% of the 7 billion tons of carbon
dioxide that causes 50% of the global warming trend. Five tons per capita per year! US
oil consumption is now the highest since 1979.
Since 1988, insurance companies paid 17 multi billion dollar weather-related claims.
There had never been one even as high as $1 billion before 1988.
Before 1900, carbon dioxide in the atmosphere was stable at 280 parts per million. The
concentration now is over 360 and the increase rate has doubled since 1958. 
1995 was globally the hottest year in over 100 years and the driest in the UK for over
300 years.
The green house effect gas and the global warming 
It is said, if the carbon dioxide increases, the Earth becomes hot. By what mechanism
does this happen?
The gas which absorbs the infra-red lays such as carbon dioxide, water vapor, and so on,
is called the green house effect gas. 
Though these gases are contained in the atmosphere by less than one percent, the
temperature of the atmosphere becomes -18?C on average if they are entirely lost from the
atmosphere.
If the green house effect gases are contained in the atmosphere, while the solar
radiation is not absorbed by these gases and reaches the Earth surface and warms it, the
infra-red radiation emitted from the Earth surface is absorbed by these gases and the
atmospheric temperature rises correspondingly. At present, since the averaged atmospheric
temperature is 15?C, the green house effect gas has the effect of warming the atmosphere
from -18?C to 15?C, i.e., 33?C.
If these green house effect gases continue increasing, the amount of absorption of the
infra-red lays increases and the atmospheric temperature may rise correspondingly. This
is why the problem of the global warming is raised. 
Schematic view of the green house effect
Trend of the green house effect gases 
Is the green house effect gases actually increasing?
The answer is YES. It has been clarified that the carbon dioxide is increasing since the
industrial revolution. It is known that the concentration of the carbon dioxide has
fluctuated for the past one hundred-thousand years, especially during the ice age etc.
However, after the industrial revolution, it has been increasing by the rate higher than
that in the past. Moreover, the increasing rate is becoming higher in recent years.
Besides the carbon dioxide, there are some other green house effect gases which are
increasing in concentration due to human activities; the methane, the freon gases, the
carbon monoxide, and the tropospheric ozone(*).
(*) The stratospheric ozone around the 20km height has the function of absorbing the
ultra-violet rays. And if it decreases, the ultra-violet rays which reach to the Earth
surface increase, which has a bad effect on living things. On the other hand, the
tropospheric ozone has the function of absorbing the infra-red rays and acts as a green
house effect gas. 
Trend of the atmospheric temperature around the Earth surface. 
While the green house effect gases are actually increasing, is the atmospheric
temperature around the land surface increasing in accordance with this?
The atmospheric temperature is affected complicatedly by various factors such as the
ocean or the Earth surface. Thus, the annual mean temperature of the whole atmosphere
fluctuates in various time scales which range from a few years to more than several
decades.
Looking at the data from 1880 to 1994, we can see that it is increasing by the rate of
0.6?C/100yr in a long range. However we have to examine quantitatively whether this
increasing tendency is due to the increase of the green house effect gases or it is part
of a variability on some longer time scale.
The problem of the global warming 
If the atmospheric temperature near the land surface rises in the whole globe, there is a
possibility that it has serious effects to the human life.
It is considered that the following climate changes may occur due to the global warming.

? Desertification in the dry area and in the semi-dry area advances. 
? Concentrated precipitation increases. 
? Sea level rises due to the thermal expansion of sea water. 
? Snowing area and frozen soil reduce. 
By these, it is considered that the natural environments are affected as follows: 
? Forests degenerate (especially in the semi-dry area). 
? Zonal climate belts shift several hundred kilometers to the pole. 
? Species which cannot adapt to the changing environments extinct. 
? The coastlines change. 
It is feared that they have bad effects on the human life socially and economically as
follows: 
? Effects on agriculture, stock raising, and forestry. 
? Effects on using water (increase of flood and shortage of water). 
? Immigration of residents near the sea coast and on the small islands. 
? Destruction of the port facilities. 
? Destabilization of topography in the frozen-soil area; increase of erosion and
landslide. 
In order to avoid these beforehand, it is necessary to predict the change of climate when
the green house effect gases increase and to consider a counterplan among all society.