The accelerating loss of Greenland’s ice sheet could raise sea levels much more than previously believed, according to a new study published in Nature Climate Change.
In August four leaders from the Partnership for Responsible Growth visited Greenland, the world’s largest island, to learn more about the problem from scientists and other experts. “It is increasingly clear that flood events are likely to become even more severe and frequent,” said John Englander, a member of our Advisory Board and the founder and president of the Rising Seas Institute. He has authored two books on the subject and advocates what he terms “intelligent adaptation.”
Greenland is now the largest single ice-based contributor to global sea-level rise, surpassing contributions from both the larger Antarctic ice sheet and from mountain glaciers globally. Greenland lies in the Arctic, which is warming much faster than the rest of the world.
To that end, about 3.3 percent of the ice sheet's total mass is likely to be lost without any further warming, according to the new study’s lead author, Jason Box of the Geological Survey of Denmark and Greenland. That would trigger nearly a foot of global sea-level rise.
The figures are a global average for sea level rise. Some places farther away from Greenland would get more and places closer, like the U.S. East Coast, would get less.
Researchers told Axios the findings are conservative, both due to quirks in its methods and to the assumption that no further global warming will take place, which is a highly unlikely scenario. “It is a very conservative rock-bottom minimum,” Box asserted. “Realistically, we will see this figure more than double within this century.”
“In fact,” said PRG co-founder and CEO Bill Eacho, “the scientists we consulted in Greenland are quite certain that the sea level rise will be significantly greater than the 10.6 inches that this study projected just from Greenland.”
“Every study has bigger numbers than the last. It’s always faster than forecast,” said
William Colgan, a co-author who studies the ice sheet from its surface with his colleagues at the Geological Survey of Denmark and Greenland.
The major issue with the new study is the lack of a time horizon attached to the predictions, according to Sophie Nowicki, an ice sheet expert at the University at Buffalo who was not involved in the research. Do you get that number by 2100, she wrote in an email to The New York Times’ Elena Shao, “or in thousands and thousands of years?”
The study’s authors “suggested much of it can play out between now & the year 2100,” wrote The Washington Post’s Chris Mooney. Englander added, “It’s impossible to precisely predict the rate of Greenland and Antarctic melting, but five to10 feet is now a realistic range for global mean sea level rise by end-of-century.”
“Obviously, the number of variables in sea level predictions is almost infinite,” noted PRG Advisory Board member Julia Nesheiwat, who also made the trip to Greenland. “How quickly will the world diversify its energy resources to lower Co2 emissions? How much will sea level & temperature rise as we move through the 21st Century? Can carbon capture have a significant impact?” A member of the U.S. Arctic Research Commission, Dr. Nesheiwat has served in influential positions during the past four presidential administrations and as Florida’s first Chief Resilience Officer.
“It’s too bad we can’t send every member of Congress to Greenland,” observed PRG co-founder and chairman George Frampton, who directs the Climate Program at the Atlantic Council’s Global Energy Center. “Seeing things with your own eyes drives home the depth of the problem. I believe more of those elected officials would see the value of an honest climate price and other measures to combat climate change.”