The debate over global warming theory is turning into a contest between two explanatory models for climate change: human activity or solar activity. Now comes news that solar activity may be declining, signaling that we may (no alarmism here) be entering a period of global cooling. Investor's Business Daily explains: Kenneth Tapping, a solar researcher and project director for Canada's National Research Council, is among those looking at the sun for evidence of an increase in sunspot activity.Solar activity fluctuates in an 11-year cycle. But so far in this cycle, the sun has been disturbingly quiet. The lack of increased activity could signal the beginning of what is known as a Maunder Minimum, an event which occurs every couple of centuries and can last as long as a century.Such an event occurred in the 17th century. The observation of sunspots showed extraordinarily low levels of magnetism on the sun, with little or no 11-year cycle.This solar hibernation corresponded with a period...(Read Full Post)