As reported in the London Telegraph, the GISS used September's temperature records instead of October's for a large chunk of Russia.
This huge error calls into question all of GISS's numbers because in explaining their "mistake" the group's spokesman claimed that it happened because GISS got the Russian temperature figures from an outside source and "did not have resources to exercise proper quality control over the data it was supplied with."
This is a big deal because GISS is one of four sources relied upon by the United Nations' Intergovernmental Panel on Climate Change for global temperature data and, "the most widely quoted, since they consistently show higher temperatures than the others."
The devil is in the details, but details don't seem to matter to the environmentalist nuts. As long as the data supports their conclusions, who cares if it is accurate.