An Overview of the Effects of Global Warming

It is important to understand the significance that globalAccording to scientists, we can with "99% confidence
warming has on not only our earth, but our daily livesconclude that current temperatures represent a real
as well. It's also important to understand the effects ofwarming trend rather than a chance fluctuation over
global warming that our children and grandchildren willthe 30-year period." Most scientists agree that the
experience in the years to come if things continue theplanet's temperature has risen 0.5 degrees Celsius
way they are now.since 1900, and will continue to increase at an
First, it's important to understand that "Global Warming"increasing rate. The environment is responding to this
is also known as the "Greenhouse effect". Instead of awarming. For instance, a study of mountain plants in
plastic or glass shield, the earth has around it a seriesthe Alps (Europe), shows that some cold-loving plants
of atmospheric gases consisting mostly of nitrogenare starting to move to higher and cooler altitudes.
and oxygen molecules. The earth is about 60 degreesThat is a possible response to increasing
Fahrenheit warmer than it would be if it didn't havetemperatures.
those atmospheric gases surrounding it. They keep theThe global effects of the greenhouse effect cannot
earth warm and protected from excess UV (Ultrabe directly predicted simply because we do not have
Violet) rays from the sun. Once warmed, theirenough knowledge in the subject. However, we have
molecules then radiate a portion of this heat energybeen able to draw direct connections between certain
back to earth, creating more warming on the surfacenatural phenomenon that supports the idea that
of our planet. It is this radiation which causessomething is changing.
atmospheric gases to move back to earth thatGlobal warming has great effect on crops and
scientists call the "greenhouse effect".weather conditions around the world. The northern
Much debate in the last five years about thehemisphere contains more land area than the southern
greenhouse effect has centered on interpretinghemisphere, and conversely, a lower percentage of
temperature numbers generated at weather stationsthe world's oceans. Since oceans absorb more heat
all over the world. The data from these thermometersthan land areas, it is not surprising that most climate
are averaged and plotted in attempts to determine justmodels predict faster heating over the northern
how fast the earth has heated up since thehemisphere than the global average. In addition, models
measurements began. There is now no doubt thepredict faster temperature increases at higher latitudes.
world is getting warmer. The thermometers show thatIf global warming trends continue, high temperatures
the world is warmer now than at any time since theeverywhere in the US may reduce US agricultural
measurements started. The year 1990 was theproductivity.
hottest year in the last century. Together with 1991, theNorthern continental areas are projected to have drier
years of 1983, 1987, 1988, and 1989, have beensummer soils, due in part to earlier snow melts in the
measured to be the warmest 6 years in the lastspring, and hotter, more cloudless summers, causing
hundred years. 1991 was the second warmest year ofextensive evaporation of ground moisture. In addition, if
the past century, perhaps due to the eruption of Mt.the inland areas of the northern hemisphere are
Pinatubo during that year. The ash from the volcano inexpected to receive less moisture, then, lake and river
the upper atmosphere blocks some sunlight to earth,levels will be lower. Some reports predict the level of
and is expected to generate a temporary two orthe Great Lakes will drop between 2 and 8 feet. River
three year cooling effect. After that time, most ashflows in the western US may be very vulnerable to
particles will have settled back to earth, and mostincrease temperatures expected as result of the
scientists expect to see the global warming trendgreenhouse effect.
continue.