Методические указания по составлению и оформлению научного доклада на профессиональную тему на английском языке. Малетина Л.В. - 26 стр.

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upward infrared radiation from the top of the atmosphere [2:755].
Radiation Absorption by Carbon Dioxide and Water Vapor
The greenhouse effect is caused by minor constituents in the atmosphere,
mainly carbon dioxide and water vapor. The earth must radiate in the 5-
micron to 30-micron region. However, water vapor is a strong absorber of
radiation over the entire thermal spectrum except in the 8-micron to 18-
micron interval. The 12-micron to 18-micron interval is largely blocked by
CO2 absorption. In fact, current CO2 levels are sufficient to make the 15-
micron band virtually opaque to infrared radiation. The earth is, therefore,
constrained to radiate its excess thermal energy in a nearly transparent
window from 8 microns to 12 microns. As anthropogenic carbon dioxide is
introduced into the atmosphere, mostly by combustion of fossil fuels,
absorption of infrared radiation in the 10-micron band and in the wings of the
15- micron band is increased. This increased absorption results in an overall
warming of the earth-atmosphere system.
Positive Feedback Mechanisms
As the climate becomes warmer, positive feedback mechanisms tend to
exacerbate the problem. Elevations in temperature decrease the solubility of
CO2 in the oceans. Therefore, as temperature increases, the oceans release
more CO2 into the atmosphere, which causes another increase in temperature.
Even more threatening is the greenhouse water vapor coupling. The
atmosphere tends to attain a definite distribution of relative humidity in
response to a change in temperature. If the temperature is increased, the
relative humidity, which is a measure of the amount of water vapor in the
atmosphere, is also increased. At the same time, the vapor pressure of water is
raised. The result is more water vapor in the atmosphere, which causes more
greenhouse effect, which raises temperatures even higher, which again
increases the water vapor in the atmosphere. This positive feedback
mechanism approximately doubles the sensitivity of surface temperature to a
change in the amount of energy absorbed by the earth [1:19].
IV. THE CARBON CYCLE
The annual increase of carbon dioxide in the atmosphere is dependent on
several factors. First is the amount of carbon dioxide produced by
consumption of carbon-based fuels. Subtracted from this amount is the carbon
dioxide that is removed from the atmosphere and stored in reservoirs, or sinks.
The most prominent sinks of carbon dioxide are the atmosphere, the oceans,
and the biosphere. Also contributing to a net increase in CO2 is the
deforestation of large land areas each year. The amount of carbon dioxide
produced from fossil fuels and the annual increase in atmospheric
concentrations are both well known. Approximately 50% of the CO2
produced from fossil fuel remains in the atmosphere. The rest is absorbed into
sinks. The proportion of CO2 that goes into each sink and the mechanisms of
CO2 removal are poorly understood.
CO2 From Fossil Fuel
Since the advent of the Industrial Revolution, about 154.4 gigatons (G ton) of
carbon have been added to the atmosphere. One gigaton is equal to one billion
tons. Even more alarming is the fact that of this 154.4 G tons, about 27%, or
45 G tons, were produced from 1970 to 1978. Overall, the use of carbon-
Discussion of
greenhouse effect
problems.

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