Posted: May 04, 2008
3:05 am Eastern
© 2008 WorldNetDaily
Methodology used by NASA to estimate rates of climate change are resulting in dramatic shifts in previously published historical temperature data, causing figures for estimated global surface temperature prior to 1970 to now be lower and figures since 1970 to now be higher – and appearing to provide evidence for those who say the Earth is warming.
John Goetz, writing last month in the science blog Climate Audit, analyzed the way NASA's Goddard Institute for Space Studies calculates estimated global surface temperatures and showed that the addition of new, contemporary data could "have a ripple effect all the way back to the beginning of a [weather] station's history."
Goetz found 32 different versions of published global annual averages going back to Sept. 24, 2005, that showed the published figures – figures used as a baseline to demonstrate change through time – changing hundreds of times.
"On average 20% of the historical record was modified 16 times in the last 2 1/2 years," he wrote. "The largest single jump was 0.27 °C. This occurred between the Oct. 13, 2006 and Jan. 15, 2007 records when Aug 2006 changed from an anomoly of +0.43 °C to +0.70 °C, a change of nearly 68 percent."
Temperature anomalies – differences between the average measured global air temperature and some long-term mean – are primary data for studies of climate change.
The magnitude of the changes in the reworked historical data observed by Goetz – 0.27 °C – is more that a third of the total average increase in global air temperature near the Earth's surface – 0.74 ± 0.18 °C – that has occurred over the last century, according to the Intergovernmental Panel on Climate Change.
A comparison of annual temperature anomalies for the United States from 1880 to 1999 further revealed that shifts in historical estimates of temperature, since NASA refined its data for the period 1930 to 1999, are biased toward global warming.
Steven Goddard, writing in The Register,
analyzed two different NASA reports of historic temperature anomalies – published in 1999 and 2007 – and showed estimates for years in the 1930s through 1970 were lowered while estimates for years from 1970 to 1999 were increased between the two reporting periods. The results, when graphed, described a temperature regime that was cooler than previously thought prior to 1970 and warmer than thought since – precisely what advocates of global warming argue but what earlier renditions of the data did not say so clearly.
That, said Goddard, defied statistical odds.
