Global Warming: A Chilled View
A Brief History
For the past several million years the climate has been dominated by ice ages, and approximately every 100,000 years the Earth's climate warms up temporarily. These warm periods, called 'interglacial periods', can last anywhere between 15-20,000 years before reverting back to a cold ice age climate. At year 18,000 and counting our current interglacial break from the Ice Age is much nearer to its end than its beginning, as can be seen:
• Approximately 15,000 years ago the earth had warmed sufficiently to halt the advance of glaciers, and sea levels worldwide began to rise.
• By 8,000 years ago the land bridge across the Bering Strait was drowned, cutting off the migration of men and animals to North America from Asia.
• Since the end of the Ice Age, Earth's temperature has risen approximately 16 degrees F and sea levels have risen a total of 300 feet! Forests have returned where once there was only ice.
In the 1970's concerned environmentalists feared a return to another ice age due to manmade pollution blocking out the sun! And since around 1940 the global climate has indeed appeared to be cooling. Then sometime in the late 1970s global temperature declines slowed to a halt and ground-based recording stations over the next 20 years began showing small and steady increases in near-surface temperatures. Fears of a Global-Cooling then changed suddenly to Global-Warming and the blame ironically laid at the feet of manmade pollution!
It is well understood in the scientific community, that Earths warming and cooling periods of approximately 40 years exists within larger 400 year periods, which in turn exist within larger periods of 20,000 years and so on..
Global temperatures over 400 years ago were at the same levels as today, the so called 'Medieval Warm Period' which existed approximately from A.D 1000 to A.D 1350 gave way to a cool period termed the 'Little Ice Age' which lasted till around A.D 1860. This period was charaterized by harsh winters, shorter growing seasons, and a drier climate. The decline in global temperatures was only 1/2 degree centigrade, but the effects of have been blamed for a host of human sufferings including the 'Irish Potato Famine' and the demise of the Viking colonies in Greenland.
"... the Earth was evidently coming out of a relatively cold period in the 1800s so that warming in the past century may be part of this natural recovery." Dr. John R. Christy leading climate and atmospheric science expert- U. of Alabama in Huntsville.
Global Warming advocats insist that this increase in global temperatures since A.D 1860 are due to the effects of 'Industrial Revolution', whereby large amounts of CO² have been released into the atmosphere from manmade sources causing a runaway 'Greenhouse Effect'.
Is man truly responsible for bringing the Earth out of the 'Little Ice Age' with his industrial pollution?
Global climate and temperature cycles are the result of a complex interplay between a variety of causes. Because these cycles and events overlap, sometimes
compounding one another, sometimes canceling one another out, it is inaccurate to imply a statistically significant trend in climate or temperature patterns from
just a few decades of data.
Unfortunately, a lot of disinformation about where Earth's climate is heading is propagated by "scientists" who use improper statistical methods, short-term
temperature trends, or faulty computer models to make analytical and anecdotal projections about the significance of man-made influences to Earth's climate.
During the last 100 years there have been two general cycles of warming and cooling recorded in the U.S. Which is currently in a second warming cycle, and overall, temperatures have showed no significant warming trend over the last 100 years. This warming trend is well-established but not well-publicized.
Each year Government press releases declare the previous year to be the "hottest year on record." The UN's executive summary on climate change, issued in January 2001, insists that the 20th century was the warmest in the last millennium. The news media distribute these stories and people generally believe them to
be true. However, as most climatologists know, these reports generally are founded on ground-based temperature readings, which are misleading. The more meaningful and precise orbiting satellite data for the same period (which are generally not cited by the press) have year after year showed little or no warming.
The problem is ground-based recording stations, many of which were originally earlier in the previous century, sited in rural areas, but over time have suffered from background bias due to urban sprawl, and the encroachment of concrete and asphalt which holds and releases heat well. Satellite measurements obviously are not limited in this way, and show no significant warming in the last 20 years they have been recording and returning data.
A Matter of Opinion
The idea that man-made pollution is responsible for global warming is not supported by historical fact. The period known as the 'Holocene Maximum' is a good example so-named because it was the hottest period in human history. The interesting thing is this period occurred approximately 5,500 B.C - 2,000 B.C long before industrial pollution.
Data taken from Ice Cores in Antarctica shows that CO² in the atmosphere has been steadily increasing for the last 18,000 years, which is long before humans invented the combustion engine. Incidentally, data shows CO² levels in the atmosphere today have reached similar levels in a previous interglacial period which existed around 140,000 years ago. This cycle lasted about 20,000 years and was known as the 'Eemian Interglacial Period' funnily enough the earth returned to a full blown ice age immediately afterward.
Seven Facts about Carbon Dioxide
• The footprint contributed by man to gases in the atmosphere accounts for only 0.28% of the 'air out there'. Approximately 99.72% of the 'greenhouse effect' is due to natural causes.
• Of the 186 billion tons of carbon from CO² that enter earth's atmosphere each year from all sources, only 6 billion tons are from human activity. Approximately 90 billion tons come from biologic activity in earth's oceans and another 90 billion tons from such sources as volcanoes and decaying land plants.
• At 380 parts per million CO² is a minor constituent of earth's atmosphere - less than 4/100ths of 1% of all gases present. Compared to former geologic times, earth's current atmosphere is CO²- impoverished.
• CO² is odorless, colorless, and tasteless. Plants absorb CO² and emit oxygen as a waste product. Humans and animals breathe oxygen and emit CO² as a waste product.
• Carbon dioxide is a nutrient, not a pollutant, and all life-- plants and animals alike benefit from more of it. All life on earth is carbon-based and CO² is an essential ingredient. When plant-growers want to stimulate plant growth, they introduce more carbon dioxide.
• CO² that goes into the atmosphere does not stay there but is continually recycled by terrestrial plant life and earth's oceans - the great retirement home for most terrestrial carbon dioxide.
• If we are in a global warming crisis today, even the most aggressive and costly proposals for limiting industrial carbon dioxide emissions would have a negligible effect on the global climate!
Some scientists believe we are "nearing the end of our minor interglacial period", and may in fact be on the brink of another Ice Age. If this is true, the last thing
we should be doing is limiting carbon dioxide emissions into the atmosphere, just in case they may have a positive effect in sustaining present temperatures.
Global climate cycles of warming and cooling have been a natural phenomena for hundreds of thousands of years, and it is unlikely that these cycles of dramatic climate change will stop anytime soon. We currently enjoy a warm Earth. Can we count on a warm Earth forever? The answer is most likely... no.
Article Source: http://EzineArticles.com/?expert=David_J_Wedge
Article Source: http://EzineArticles.com/7191154