News and Commentary

NARRATIVE FAIL: One Of Largest Glaciers On Earth That Shrank Is Growing Again

In a blow delivered to global warming purveyors, a new study discovered that a massive Greenland glacier that had been shrinking rapidly is expanding again.

NBC News reports that a new study published in Nature Geoscience examined the Jakobshavn glacier, in central west Greenland, the ice sheet’s fastest glacier and largest by volume discharge, and found that as opposed to the situation in 2012, when the glacier was shrinking 1.8 miles every year while thinning roughly 130 feet, over the last two years the process has been reversed.

The abstract for the study notes that the glacier “has been the single largest source of mass loss from the Greenland Ice Sheet over the last 20 years. During that time, it has been retreating, accelerating and thinning.” It links the growth and thickening of the glacier over the last two years to “to concurrent cooling of ocean waters in Disko Bay that spill over into Ilulissat Icefjord,” adding, “Ocean temperatures in the bay’s upper 250 m have cooled to levels not seen since the mid 1980s.”

The scientists note that their information was gleaned from two NASA data sets: the radar altimetry of the Oceans Melting Greenland mission and the laser altimetry of Operation Icebridge. The study states, “Between 2016 and 2017, we observe ice thickening of 20 to 30 m in the vicinity of the front … Repeat Glacier and Ice Surface Topography Interferometer (GLISTIN) measurements in 2018 show that the thickening continued at a similar rate near the front, but has now extended as far as 80km upstream and has spread laterally.”

The study acknowledges, “Over the past several years, ocean temperatures have cooled on the continental shelf in the vicinity of Jakobshavn Isbrae. We find that ocean temperatures in Disko Bay below about 150 m cooled by nearly 2 degrees centigrade between 2014 and 2016.”

Most importantly, the study states, “Jakobshavn Isbrae witnessed three decades-long episodes of rapid thinning since the beginning of the twentieth century. The latest started in 1997 and our observations of recent slowing and thickening could signal the end of that episode by 2017. Such episodic course reversals underline the difficulty of projecting contemporary trends into the future to assess glacier contribution to sea-level rise.”

Study lead author Ala Khazendar, a NASA glaciologist on the Oceans Melting Greenland (OMG) project, said that the natural North Atlantic Oscillation vacillates between climbing and dropping; he added that although the water can get cooler, ultimately it will get warmer and the melting will increase.

Despite the study’s warning that prediction of the future is a difficult and nebulous pursuit, some scientists still served their warnings: Geological Survey of Denmark and Greenland ice and climate scientist Jason Box asserted, “That was kind of a surprise. We kind of got used to a runaway system. The good news is that it’s a reminder that it’s not necessarily going that fast. But it is going.”

University of Washington ice scientist Ian Joughin echoed that it would be “grave mistake” to assume from the study that global warming wasn’t real, adding that what the scientists found was “to a large extent, a temporary blip. Downturns do occur in the stock market, but overall the long term trajectory is up. This is really the same thing.”