Global Warming
Essay by review • February 16, 2011 • Essay • 905 Words (4 Pages) • 1,045 Views
Global Warming
Global warming is a unique problem facing humankind that requires changes in
people's lifestyles. To know that one day the polar icecaps could melt is a
scary thought. If global warming continues to increase the earth's atmospheric
temperatures, the melting of the polar ice caps could become a reality. This
would cause dreadful devastation to many parts of the world. There would be
floods, heat waves, and destruction of aquatic life, scorched forests and
disappearing species. If global warming continues to go unattended, it will
slowly destroy the earth's ecosystems and the life that depends on them.
Melting of ice and snow
Further evidence of widespread warming comes from observations of seasonal snow
and frozen ground coverage. The extent and duration of frozen ground have
declined in most locations. Snow cover in the Northern Hemisphere has declined
about five percent over the past 30 years, particularly in late winter and
spring, and the freezing altitude has risen in every major mountain chain.
Alpine and polar glaciers have retreated since 1961, and the amount of ice
melting in Greenland has increased since 1979. Over the past 25 years, the
average annual Arctic sea ice area has decreased by almost five percent and
summer sea ice area has decreased by almost 15 percent. The collapse of the
Larsen Ice Shelf off the Antarctic Peninsula appears to have no precedent in the
last
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11,000 years.
The Role of Natural Variability
Human induced warming is superimposed on natural processes to
produce the observed climate. Because these natural fluctuations play a role in
determining the precise scale and supply of temperature in a particular year,
record heat in any year and find that it is not highly significant. What is
noteworthy; however is that global average temperatures experienced a net rise
over the twentieth century, and the average rate of this rise has been
increasing. When scientists attempt to reproduce these twentieth century trends
in their climate models, they are only able to do so when including human
produced heat trapping emissions in addition to natural causes.
Hottest years on Record
Global average surface temperatures pushed 2005 into a virtual tie with 1998 as
the hottest year on record. For people living in the Northern Hemisphere most of
the world's population 2005 was the hottest year on record since 1880, the
earliest year for which reliable instrumental records were available worldwide.
The year 2005 exceeded previous global annual average temperatures and is also
part of a longer term warming trend exacerbate by the rise of heat trapping
gases in our atmosphere that is due primarily to our burning fossil fuels and
clearing forests. Nineteen of the hottest 20 years on record have occurred since
1980. The record surface temperatures of the past 20 years reinforce other
indications that global warming is under way. For example, the observed rise in
average surface temperatures has been accompanied by warming of the atmosphere
and oceans, and increased melting of ice and snow. A 2005 analysis of
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satellite observations of temperature trends in the troposphere the layer of
atmosphere extending about five miles up from Earth's surface uncovered errors
in previous studies. Recent studies show that air temperatures has increased in
the past 20 years or so, consistent with the basic understanding
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