An Arctic heat wave

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A scary illustration appeared on the Internet recently when NASA posted side-by-side graphics of Greenland as viewed from space. On the left, a July 8 image shows the world’s largest island mostly white, indicating its year-round ice cover. The right-hand view, taken July 12, imposes pink on most of the land mass to represent a thawing over 97 percent of the ice sheet that occurred in the four-day period.

Is this an omen of the dreaded “tipping point,” at which global warming spins out of control and sets in motion disasters that threaten the very survival of civilization? Or is it just part of a natural cycle? Who knows?

The stark contrast between the two maps may have led some viewers to conclude that the Greenland ice sheet had already vanished. In fact, the cap is two miles deep at its thickest point. What the illustration indicates is surface melting. NASA scientist Tom Wagner told the Associated Press summer thawing periodically happens – one of similar magnitude last occurred in 1889 – and he doesn’t yet know whether manmade global warming accelerated the process. Some of the melt water seemed to be refreezing after the four-day warm spell subsided.

Greenland, north of Canada and just 450 miles from the North Pole, is having an unseasonably warm summer (relatively speaking), as we are. AP quoted University of Georgia climatologist Thomas More as comparing the northern heat wave to the one that’s baking the breadbasket of the American Midwest. Stubborn high-pressure systems get at least part of the blame in both cases.

There’s compelling cause to watch what’s going on in the Arctic because scientists say a total melting of the Greenland ice sheet would raise the sea level more than 23 feet, inundating coastal areas around the world. The question we need to ask ourselves now is whether human activity – our profligate burning of fossil fuels, which increases the atmospheric concentration of heat-trapping greenhouse gases – could turn a natural event into something far more catastrophic.

This isn’t the first time Greenland has served as a bellwether for global climate change. Around 980 A.D., during the Medieval Warm Period, a Viking named Eric the Red saw opportunity on the fringes of the thawing island. The Norsemen, typecast as rapists and pillagers, sometimes got a yen to beat their swords into plowshares and settle down on nice little farms. Eric, a bit of a real estate pitchman, christened his discovery Greenland in hopes the appealing name would lead other Scandinavians to join him there.

Unfortunately, the pastoral-minded Vikings underestimated the hardships of farming a place where ice is not far removed from the coastal green lands. Archaeologists have turned up bones of settlers who appeared to have been stunted from malnutrition resulting from the abortive agricultural venture.

The final blow came when the warmth of the era gave way in the fourteenth century to a new cooling trend. It would culminate in the “Little Ice Age” that gripped the globe until the 1800s.

What the recent Arctic thaw portends for the planet is unclear. But if this summer’s heat and drought punctuated by severe storms becomes the new normal, the consequences could be just as calamitous for us as a cooling climate was for Greenland’s Viking farmers.

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  • Box, J. E.(2012) predicted, from albedo studies for the last decade, that it is reasonable to expect 100% melt area over the ice sheet within another similar (to the last) decade of warming. Commenting on the NASA data, he says this prediction may be coming true already. In addition, researchers have found a way to use GPS to measure short-term changes in the rate of ice loss on Greenland -- and reveal a surprising link between the ice and the atmosphere above it (reported in ScienceDaily (July 24, 2012. The study, published in the early online edition of the Proceedings of the National Academy of Sciences, hints at the potential for GPS to detect many consequences of climate change, including ice loss, the uplift of bedrock, changes in air pressure -- and perhaps even sea level rise.

  • The biggest difference in historical climate change and today's anthropogenic change is time...lots of it. Where it used to take 1,000 years to change it now is taking 50. This presents unique and very difficult challenges for any species of plant or animal to migrate to habitat that is necessary for life. Another much more recent impediment for this migration is civilization, namely vast urban areas built out of concrete and steel with cars, trucks and trains flying around on it. These would prove impossible for small animals and insects to traverse, much less a tree. We are likely to see mass extinctions as a result.