by Monte Naylor
A comparison of NOAA-computed temperature trends with the “raw” historical temperature data.
The global historical surface temperature record is presented as the fundamental evidence for global warming. The climate divisions of many official agencies such as NOAA and NASA say that the global surface temperature has increased about 1.25 °C (2.25 °F) in the preceding 120 years.
They also propose that the driving force for atmospheric warming is the increasing amount of atmospheric carbon dioxide from human industrial emissions occurring mostly in the latter half of the 20th century and continuing to present day. The argument that industrial emissions of carbon dioxide is significantly warming the atmosphere is not without controversy (3), but the official reporting of the historical surface temperature record is broadly accepted as correct by the public and many scientists.
Some climate scientists, however, are skeptical that the NOAA and NASA historical surface temperature reporting is accurate. My study examines a specific area in the United States, roughly 1600 square miles of the northern Colorado Front Range, revealing NOAA’s methods of temperature trend computation and their temperature trend conclusions for this area. Additionally, I compare NOAA’s temperature history to the ‘raw’ temperature data, appropriately adjusted.
For the 48 contiguous United States, NASA claims that the surface temperature in the last 120 years has increased about the same amount as the global temperature, 1.2 °C (2.1°F), although the temperature trend is not as linear as the global trend.
THE OFFICIAL COLORADO SURFACE TEMPERATURE HISTORY
Specifically, for Colorado, NOAA reports that the mean surface temperature has increased about 1.3 °C (~2.4 °F) in the last 120 years, slightly more than the official global temperature increase.
CASE STUDY OF THE NORTHERN COLORADO FRONT RANGE TEMPERATURE HISTORY
One way to verify the veracity of these officially reported temperature trends is to obtain the “raw” historical temperature data of individual long-term weather stations for a specific area and attempt to recreate the temperature histories by implementing logical, easily understood computational methods.
In this study of the historical temperature record of the northern Colorado Front Range, I examine the original temperature data of this area, NOAA’s methods of adjustment, and their final rendering of the temperature history.
I also present a simplified statistical averaging version of the temperature history for the preceding 115 years for the northern Colorado Front Range. Here is the summarizing graph of this study – the difference between the two temperature trends is significant.The NOAA temperature trend, determined from an average of their homogenized USHCN station histories for the northern Colorado Front Range, shows an increase in temperature from 1900 to 2015 that is 2 °F greater than the trend my study revealed. Why do these two historical temperature trend calculations of the same region of Colorado vary so much?
For those interested in viewing the complete study, a narrated PowerPoint video, it can be viewed at https://vimeo.com/196878603/b9ea716a74
Biosketch: Monte Naylor is the Owner of GTS Energy Consulting in the Denver area. He has a B.S. in Geology from the Idaho State University and a M.S. in Geophysics from the Colorado School of Mines.
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