NASA’s Goddard Institute for Space Studies, whose global temperature reports are frequently cited by the media as the definitive measurement of global temperature trends, has been caught doctoring raw temperature data in New Mexico to make a long-term cooling trend look like a warming trend.
The incident is another in a series of erroneous temperature reports by the agency that have invariably erred on the side of reporting more warming than has occurred in recent years.
Recorded Temps Contradict GISS
California meteorologist Anthony Watts examined the temperature history, as reported by the U.S. Historical Climatology Network (USHCN), for Santa Rosa, New Mexico. The trend, he found, is one of long-term decline, especially since the 1930s, as shown in the accompanying figure. (See Figure 1.)
Watts then examined the temperature history for the same town, this time as reported by NASA’s Goddard Institute (GISS). The GISS chart was entirely different. As shown in Figure 2, GISS reports a long-term increase in Santa Rosa temperatures.
The difference between the two organizations’ temperature reports for Santa Rosa, New Mexico is obvious in Figure 3, in which the GISS temperature report is superimposed on the USHCN temperature report.
USHCN reports a decline of nearly one-half degree Celsius during the twentieth century, while GISS reports a temperature increase of one-half a degree.
Even more strikingly, USHCN shows temperatures from 1996 to 2005 were significantly below the long-term average, and even the one-year anomaly of 2006 was up to a full degree Celsius cooler than several years in the 1920s and 1930s. GISS, by contrast, claims temperatures between 1996 and 2005 were warmer than the long-term average and that 2006 was nearly a full degree Celsius warmer than any other year on record.
GISS ‘Adjusting’ the Data
So how is it that the two organizations arrive at such different conclusions regarding the temperature trend for Santa Rosa? USHCN measures temperature by taking daily readings from an immobile temperature station. GISS compiles its reports by collecting the USHCN temperature readings and then subjecting them to secret adjustments, allegedly to correct for artificial influences such as land-use changes.
Santa Rosa, New Mexico was a small town with a population of slightly more than 10,000 people in 1905, two years before the USHCN temperature record began. It grew into a city of 113,000 people in 1991 and has a population of 158,000 today.
As scientists have extensively documented, and as most people who have lived near a city know, city centers produce a significant amount of heat that makes them warmer than the surrounding region.
In short, as a population center grows, so does its temperature, for reasons wholly unrelated to global temperature variations.
This urban heat island effect makes the GISS report especially curious. The growth of Santa Rosa and its urban heat island effect mean the long-term temperature record should be adjusted downward to compensate for the growth of the city’s heat signal.
Yet GISS, by adjusting the raw temperature data upward instead of downward, treats the city as if it has lost population since 1900 and especially since 1980.
James M. Taylor ([email protected]) is a senior fellow of The Heartland Institute and managing editor of Environment & Climate News.