Geography Reference
In-Depth Information
Figure 18-5:
While the effects
of acid rain are
global, the
greatest impacts
are felt in regions
downwind from
major
source
areas.
People who live in areas that suffer the effects of pollution (such as acid rain) tend to be among the
most committed to finding a remedy. But how can you affect a solution to a problem that originates
outside of your jurisdiction — in another state or country? Assuming no treaties or protocols have
been broken, about all one can do is encourage your neighbors to clean up their act. In the case of
acid rain, that is going to take some doing because so much of the problem is associated with fossil
fuel consumption that is likely to continue for decades to come.
Getting warmer
Global warming
is the term used to describe the increase in the average temperature of the atmo-
sphere that has been occurring during the past several decades. This has ominous implications for sea
level rise and local climate changes of various sorts. But why is global warming happening? Is it a
natural process or the result of human activity? And can the process be slowed or reversed?
The Principal suspects
Several ice ages came and went long before
Homo sapiens
emerged as a major instrument of global
change. That means that natural mechanisms capable of effecting significant global temperature
change over time must exist. Perhaps, therefore, the present warming trend is merely part of a natural
cycle that has occurred in the past, is happening at present, and is likely to repeat in the future. Or
perhaps it is the result of some other natural cause that we have yet to identify.
On the other hand, the warming trend may be the result of atmospheric changes for which humans
are responsible. Since the beginning of the Industrial Revolution in the mid- to late- 1700's, humans
have consumed (burned) large quantities of coal, petroleum, and natural gas to operate vehicles and
machinery, provide power for manufacturing facilities and electrical utilities, and to heat up and cool
down homes and buildings. In the process, huge quantities of certain gases have been added to the
