Cold Snap Plus Global Warming Do Add Up

The Artic Oscillation resulting from a pattern of high sealevel pressure over the Arctic has led to "weaker westerly winds that typically pin cold air closer to the North pole...Cold snaps and bouts of natural cooling that could last years are expected naturally even as the climate continues on a long-term warming trend, forced by man-made emissions." John Wallace, an atmospheric science professor from the University of Washington, said that the weakened jet stream has allowed cold Arctic air to creap into more southern latituded.

This link, to a NASA Earth Observatory news letter, contains comments from James Hansen, who as you all know, is a strong advocate of anthropogenic global temperature interference. That aside, NASA's Goddard Institute for Space Studies has determined that the year 2009 was tied for the second hottest year on record.

Frankly, there is still too much scientists don't know yet to be certain that natural warming trend causes are not an even greater influence.