Old Well: UNC Chapel Hill Campus

Friday, June 17, 2011

Coming Ice Age?

 

You may have seen talk in the media of what’s happening these days with our sun, that solar orb we take for granted, thanks to its regularity. And yet even the sun can prove volatile and like all suns, will ultimately flame out long after you and I  have passed into molecules. 

Things are happening these days with our sun.  Solar wind is the slowest in 50 years and sunspot activity is very passive.  Magnetic fields that cause sunspots have been weakening for some time, while winds that are usually found beneath the sun’s visible surface are currently eluding our detection.  Climate scientists say the sun is going into mini-hibernation. 

All of this ignites speculation and fuels the debate between those who argue global warming and those who dismiss it as simply just another cycle.  The opponents of global warming argue that the sun’s present passivity means that instead of earth heating-up, it will be cooling down, a convenient fix to say the least. 

Scientists at the National Space Observatory (NSO) tell us that these changes in the sun could impact the earth, perhaps ushering in a “Grand Minimum,” or more conversationally, a Little Ice Age”: a “70-year period with virtually no sunspots [which occurred] during 1645-1715”  ( http://www.americanthinker.com/blog/2011/06/a_mini-ice_age_on_the_way.html). 

According to NASA, that period featured frozen rivers normally ice free and snow fields year-round at lower attitudes (American Thinker). Is another Little Ice Age our looming destiny?

Not so!  Climate scientists, not astronomers and NASA, are the experts we should rely upon for our conclusions, and many of them believe that a mini-hibernation of the sun, while it may produce a “grand minimum,” cannot appreciably cool the earth to offset the present global warming.  In fact, they’ve conducted simulations to project what would happen if  a “grand minimum” started now and lasted until 2100, or thirty years longer than the Little Ice Age of 1645-1715.  At most, the earth would cool only by 0.3 celsius. 

To offset  global warming trends,  the effects of “grand minimum” would need to be at least 10 times greater than what the simulations suggest as the possible maximum consequence to overcome the effects of climate change.  Present projections have it that emission of greenhouse gases will ultimately cause global temperatures to increase anywhere from 2 to 4.5 degrees (http://www.wired.com/wiredscience/2011/06/solar-minimum-climate/).  

Alas, despite some who make sport of global warming as a cantankerous “sky is falling” syndrome, arguing for a cooling earth as our ultimate scenario, if any at all, global warming is a sobering fact; more specifically, our exponential increase in greenhouse gases poses a lethal risk to our survival and that of our fellow creatures.  We ignore this truth at our peril. (See my earlier post,  February 3, 2011, on global warming’s insidious threat.)