Greenland Ice Melt: Past and Present

Frauenfeld et al. (2011) write that the "total annual observed melt extent across the Greenland ice sheet has been shown to be strongly related to summer temperature measurements from stations located along Greenland's coast, as well as to variations in atmospheric circulation across the North Atlantic," and they indicate that the total extent of Greenland ice melt "has been increasing during the last three decades," with the melt extent observed in 2007 being "the greatest on record according to several satellite-derived records." Therefore, one could well ask, if these several observations might not constitute a manifestation of what climate alarmists typically describe as one of the major consequences of the supposedly unprecedented rate and degree of recent global warming?

In an exercise designed to broach this question, Frauenfeld et al. created, as they describe it, "a record of total annual ice melt extent across Greenland extending back approximately 226 years by combining satellite-derived observations with melt extent values reconstructed with historical observations of summer temperatures and winter circulation patterns."

Analyzing the record, the three U.S. researchers report that "the recent period of high-melt extent is similar in magnitude but, thus far, shorter in duration than a period of high melt lasting from the early 1920s through the early 1960s," and they say that the greatest melt extent over the last two and a quarter centuries did indeed occur in 2007. However, as they go on to say, "this value is not statistically significantly different from the reconstructed melt extent during 20 other melt seasons, primarily during 1923-1961."

Frauenfeld et al. conclude that "there is no indication that the increased contribution from the Greenland melt in the early to mid 20th century ... resulted in a rate of total global sea level rise that exceeded ~3 mm/yr." And they note that this observation suggests that "Greenland's contribution to global sea level rise, even during multi-decadal conditions as warm as the past several years, is relatively modest," which is a far, far cry from the catastrophic result climate alarmists claim should occur in the face of their unprecedented global warming claim.