We have reported that November 2007 and especially December 2007 were the coolest months since January 2000, according to the RSS MSU satellite records. Two weeks ago, however, we learned about an error in the RSS computation located by John Christy and Roy Spencer, their competitors from UAH MSU. Once the error is corrected, all months in 2007 warm up (on paper) by roughly 0.1 °C.RSS MSU (graph) shows that January 2008 was the coldest month since January 2000 when we were enjoying the most recent, similar La Nina (the anomalies between 20°N and 20°S are similar in early 2000 and early 2008). The global temperature anomaly in January 2008 was -0.080 °C (thanks, Kate), meaning that the month was cooler than the average January on their record. Later, UAH MSU confirmed that it was cooler: -0.05 °C.
This time, it was the Northern Hemisphere that was unusually cool: recall the recent record snowstorms in China, cold records at places in the U.S., deadly freezing weather in India, and the peaceful snow in Baghdad and elsewhere in the Middle East. The hemispherical temperature anomaly was -0.120 °C, the coldest reading in this column since January 1997, the third coldest reading among the 172 months after September 1993, and a figure cooler than April 1998 by more than 1.2 °C.