#25 Greenland’s Meltwater Contributes to Rising Sea Levels

by Project Censored
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In February 2015, Tim Radford reported for the Climate News Network that atmospheric warming is capable of reaching thousands of meters below Greenland’s massive ice sheet, potentially increasing the glaciers’ rate of flow and creating pools of “meltwater” trapped below the ice. Two separate but related studies confirmed that surface melt can drain down to fill concealed lakes under the ice, ultimately contributing to rising sea levels.

A team led by Ian Howat of Ohio State University found “the first direct evidence for concentrated, long-term storage, and sudden release, of meltwater” at the bed of the Greenland ice sheet. The team observed and measured a depression, two kilometers (approximately 1.25 mile) wide and seventy meters (over seventy-five yards) deep in the icecap of southwest Greenland. “The fact that our lake appears to have been stable for at least several decades, and then drained in a matter of weeks—or less—after a few very hot summers, may signal a fundamental change happening to the ice sheet,” Howat said. As Radford reported, the slumped crater suggested a holding capacity of more than thirty million cubic meters of water, which had suddenly drained away.

A second team of researchers, led by Cornell University’s Michael Willis, also studied the crater, which they discovered in 2011. Their report estimated a rate of flow of 215 cubic meters (over 56,000 gallons) per second from the subglacial lake. The researchers also reported that, “As the lake beneath the ice fills with surface meltwater, the heat released by this trapped meltwater can soften surrounding ice, which may eventually cause an increase in ice flow.”

Together, the studies indicated that the effects of atmospheric warming can reach far below the ice sheet, warming the glacial base and potentially increasing its rate of flow. As Radford wrote, “Were all Greenland’s ice to melt, sea levels would rise catastrophically. At least one billion people live on coasts and estuaries vulnerable to a mere one metre rise.”

Although corporate news media have frequently and prominently covered aspects of climate change—and debates over its reality—coverage of the melting Greenland ice sheet has been limited. (Corporate media coverage of climate change is often problematic. For one example, see “Corporate News Ignores Connections between Extreme Weather and Climate Change,” Censored 2015, 50–52.) In March 2015, a Washington Post article—focused on research indicating that global warming is slowing the circulation of the world’s oceans—mentioned the melting of Greenland’s ice sheet only in passing, as one factor contributing to the slowing circulation. By contrast, a January 2015 Los Angeles Times article provided substantive coverage of the role played by a University of California, Los Angeles, team of researchers in documenting the massive melt of the Greenland ice sheet.

Readers concerned with this topic should see Jeff Orlowski’s 2012 documentary film, Chasing Ice, which depicts environmental photographer James Balog and his Extreme Ice Survey’s ongoing efforts to document disappearing arctic ice.

Tim Radford, “Greenland’s Hidden Meltwater Lakes Store Up Trouble,” Climate News Network, February 5, 2015, http://www.climatenewsnetwork.net/greenlands-hidden-meltwater-lakes-store-trouble/.

Student Researcher: Elora West (Burlington College)

Faculty Evaluator: Rob Williams (Burlington College)