Scientific American:

The cold snap that sent temperatures plunging last week and brought the most frigid new year in recorded history, in some places, had nothing to do with climate change, according to a new study.

In recent years, climate scientists have studied the connection between global warming and freezing temperatures. They are examining how shifting air patterns over the Arctic, and their incursion into North America and Europe, are connected to climate change.

But the two-week deep freeze didn't carry the hallmarks of human activity, according to a rapid attribution study from Climate Central, a science communication project based in Princeton, N.J. World Weather Attribution, a group of international researchers, performed the analysis.

Temperatures in some parts of the country, including Buffalo and Detroit, were more than 20 degrees Fahrenheit below normal for this time of year. Such events are increasingly rare, and the group found that wintertime temperatures are actually increasing in the United States. That is to be expected in a warmer world, the authors wrote.

"We conclude that this was an exceptional two-week cold wave in the area in the current climate," the authors wrote. "Cold outbreaks like this are getting warmer (less frequent) due to global warming, but cold waves still occur somewhere in North America almost every winter."

Go to link