Saturday, April 14, 2007

Playing With Numbers

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Playing with Numbers
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 years or a few decades of data.

Unfortunately, a lot of disinformation about where Earth's climate is heading is being 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. We are currently in the second warming cycle. Overall, U.S. temperatures show no significant warming trend over the last 100 years (1). This has been 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 believed 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.
Dr. Patrick Michaels has demonstrated this effect is a common problem with ground- based recording stations, many of which originally were located in predominantly rural areas, but over time have suffered background bias due to urban sprawl and the encroachment of concrete and asphalt ( the "urban heat island effect"). The result has been an upward distortion of increases in ground temperature over time(2). Satellite measurements are not limited in this way, and are accurate to within 0.1° C. They are widely recognized by scientists as the most accurate data available. Significantly, global temperature readings from orbiting satellites show no significant warming in the 18 years they have been continuously recording and returning data (1).

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