NASA'S Goddard Institute for Space Studies (GISS) is one of the world's primary sources for climate data. GISS issues regular updates on world temperatures based on their analysis of temperature readings from thousands of monitoring stations over the globe.

GISS' most recent data release originally reported last October as being extraordinarily warm-- a full 0.78C above normal. This would have made it the warmest October on record; a huge increase over the previous month's data.

Those results set off alarm bells with Steve McIntyre and his gang of Baker Street irregulars at Climateaudit.org. They noted that NASA's data didn't agree at all with the satellite temperature record, which showed October to be very mild, continuing the same trend of slight cooling that has persisted since 1998. So they dug a little deeper.

GIDD Temp Data Error
GISS's October Data. The large reddish-brown area in Russia is actually September readings.
McIntyre, the same man who found errors last year in GISS's US temperature record, quickly noted that most of the temperature increase was coming from Russia. A chart of world temperatures showed that in October, most of Russia, the largest nation on Earth, was not only registering hot, but literally off the scale. Yet anecdotal reports were suggesting that October was actually slightly colder than normal. Could there be another error in GISS's data?

An alert reader on McIntyre's blog revealed that there was a very large problem. Looking at the actual readings from individual stations in Russia showed a curious anomaly. The locations had all been assigned the exact temperatures from a month earlier-- the much warmer month of September. Russia cools very rapidly in the fall months, so recycling the data from the earlier month had led to a massive temperature increase.

A few locations in Ireland were also found to be using September data.

Steve McIntyre informed GISS of the error by email. According to McIntyre, there was no response, but within "about an hour", GISS pulled down the erroneous data, citing a "mishap" and pointing the finger of blame upstream to the National Oceanic and Atmospheric Adminstration (NOAA).

NOAA's Deputy Director of Communications, Scott Smullens, tells DailyTech that NOAA is responsible only for temperature readings in the US, not those in other nations.

The error not only affected October data, but due to the complex algorithm GISS uses to convert actual temperature readings into their output results, altered the previously published values for several other months as well. The values for August 2008, for instance, changed by 0.11C and the global anomaly as far back as 2005 increased by a hundredth of a degree.

GISS is run by Dr. James Hansen, a strident global warming advocate who has accused oil companies of "crimes against humanity". Hansen recently made headlines when he travelled to London to testify on behalf of a group of environmentalists who had damaged a coal plant in protest against global warming. Hansen also serves as science advisor to Al Gore.

Dr. Hansen could not be reached for comment.