The decline of Mayan civiliation may indeed have been influence by solar induced global warming. One effect could have been an increase in severe droughts. This seems to be one of the causes of the Darfur crisis. Also in the last global warmest period in historical times, sea levels were 5 to 8 feet higher than they are today. Whether global warming is natural and man caused, we better start thinking about sea levels pretty darn quick. New Orleans was only a wake up call.
Well, the “end” of the Mayan calender in 2012 with the second Venus transition of the sun will match the max point of this solar cycle.