Page 63 - Fundamentals of Air Pollution 3E

Questions 39

ozone layer is expected to take place very slowly. Thus there was a lag
from the first release of these gases until an effect was seen. Similarly, on
cessation of use of these materials worldwide, there will be another lag
before an effect is noted (See Chapter 11.)
Another global problem is that generated by carbon dioxide, which is
not normally considered an air pollutant. Because carbon dioxide is a
"greenhouse gas," it absorbs and reradiates infrared radiation. At night
the ground loses heat and cools, primarily through infrared radiation. But
a portion of this radiation is intercepted by the carbon dioxide in the air
and is reradiated both upward and downward. That which is radiated
downward keeps the ground from cooling as rapidly. As the carbon dioxide
concentration continues to increase, the earth's temperature is expected to
increase.
A natural air pollution problem that can cause global effects is injection
into the atmosphere of fine particulate debris by volcanoes. The addition
of this particulate matter has caused some spectacular sunsets throughout
the earth. If sufficient material is released, it can change the radiation
balance. Blocking of the incoming solar radiation will reduce the normal
degree of daytime warming of the earth's surface. A "mini-ice age" was
caused in the mid-1800s, when a volcanic mountain in the Pacific erupted.
The summer of that year was much cooler than usual and snow occurred
in July in New England.

SUGGESTED READING

CritchHeld, H. ]., "General Climatology," 4th ed. Prentice-Hall, Englewood Cliffs, NJ, 1983.
Knap, A. H. (ed.), "The Long-Range Atmospheric Transport of Natural and Contaminant
Substances." Kluwer Academic Press, Hingham, MA, 1989.
Kramer, M. L., and Porch, W. M., "Meteorological Aspects of Emergency Response." Ameri-
can Meteorological Society, Boston, 1990.
Landsberg, H. E., "The Urban Climate." Academic Press, New York, 1981,

QUESTIONS

1. What situation of emission has the potential to produce the greatest local problem?
2. What are the two types of air pollution problems found in urban areas?
3. What are the two primary gaseous pollutants that transform to fine-particle form during
long-range transport?
4. What are major concerns on the continental scale?
5. What are two global issues?