Geology Reference
In-Depth Information
Geo-Focus
Global Warming and Climate Change, and How They Affect You
The greenhouse effect, global warming,
climate change—these headlines and
topics are in the news all the time and
are global issues that affect us all and the
planet we live on. But just how will
global warming and the resultant cli-
mate change personally affect you? Are
they something that you should really
be concerned about? After all, there are
exams to worry about, graduation, fi nd-
ing a job, and that doesn't even include
the everyday issues we all must deal with,
not to mention your personal life. Yet,
part of the college experience is exam-
ining and debating the “big picture”
and issues facing society today. So what
about global warming and you?
You may recall we talked about the
greenhouse effect and its relationship
to global warming. The greenhouse ef-
fect helps regulate Earth's temperature
because as sunlight passes through the
atmosphere, some of
the heat is trapped in
the lower atmosphere
and not radiated back
into space, thus effec-
tively warming Earth's
surface and atmosphere.
The issue is not whether
we have a greenhouse
effect, because we do,
but rather the degree to
which human activity,
such as the burning of fossil fuels, is in-
creasing the greenhouse effect, and thus
contributing to global warming.
Based on many studies using a
variety of techniques, it is clear that
carbon dioxide levels have increased
since the Industrial Revolution in the
19th century. (Carbon dioxide is one
of the greenhouse gases that allows
short-wavelength solar radiation to
pass through it, but traps some of the
long-wavelength radiation refl ected
back from Earth's surface.) Further-
more, global surface temperatures have
increased about 0.6°C since the late
1800s, and about 0.4°C during the past
25 years. However, this warming trend
has not been globally uniform and
some areas, such as the southwestern
part of the United States, have actually
cooled during this time period.
One thing we must be careful about
is mistaking regional trends for global
Image not available due to copyright restrictions
a
Map showing the location of the Maldives Islands
in the Indian Ocean.
◗
Figure 1
A rise in sea level due to global warming could easily submerge the Maldives islands
With industrialization and its accompanying burn-
ing of tremendous amounts of fossil fuels, carbon diox-
ide levels in the atmosphere have been steadily increasing
since about 1880, causing many scientists to conclude that
a global warming trend has already begun and will result in
severe global climate shifts. Most computer models based on
the current rate of increase in greenhouse gases show Earth
warming by as much as 5°C during the next hundred years.
Such a temperature change will be uneven, however, with
the greatest warming occurring in the higher latitudes. As a
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