Thursday, December 23, 2010

Snow for Christmas…and the 4th of July

 Christmas Mammoth (with snow added by me)

In trying to keep with a holiday season theme, we will look at snow.  Snow in copious amounts.

Although the general concern of the moment is with global warming, a side concern associated with this warming is actually intermediate cold spells that occur within warming trends.
One such cold spell,  that is just prior to the historical period is the extended cold and dry period referred to as the Younger Dryads (primer).  The current theory is that this event was spurred by the breaking of an enormous ice dam in North America and the rushing into the Atlantic of enormous quantities of fresh water.  This fresh water cut off the North Atlantic conveyor belt which helps bring warmer temperatures to Europe, and in general acts as a moderating force on global temperatures.
The speed with which this event can occur is much faster  than the gradual pace of global warming, and is thought to be possible within a decade’s time span.  About a year ago there was concern that the conveyor belt had shut down.   We have been informed that this was a false alarm.  It is a little unclear how they know what the historical basis point is if they have not had good measurements until now:  but never mind.  The general trend has been confirming as far as the theory goes.

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