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No Stopping the Collapse of West Antarctic Ice Sheet NEWS&ANALYSIS chairs. “She is one of our young stars,” says society” and for “moral damage incurred Science, Maged Said, a senior associate in the Tarek Shawki, AUC’s dean of the School of [by] MUST.” Tahoun Law Offi ce, the Giza, Egypt–based Sciences and Engineering. The lawsuit, “[The case] seems completely un rea- fi rm representing MUST, repeated the initial however, cast a shadow. Rumors that she had sonable to me,” says Gregory Marczynski, a claim that Siam had violated her obligations stolen grant money were rife, Siam says. biochemist at McGill University in Montreal, to the university by depriving it of the grant. In November 2012, a court found in Canada, and Siam’s former graduate adviser, If the verdict is upheld, it would “seriously Siam’s favor, stating that because MUST who describes her work as “cutting-edge” and undermine researchers’ willingness to hadn’t given her an employment contract, “highly collaborative.” Although the order to fi le grants” if they were even considering she was free to leave. MUST appealed and on compensate MUST for missing out on the a career move, says Lisa Rasmussen, a 16 March, Cairo’s Court of Appeal grant may be in the “realm of reason,” adds research ethicist at the University of North overturned the lower court’s verdict, Aly El Shalakany, a partner at the Shalakany Carolina, Charlotte. If scientists are not ruling that Siam had nevertheless broken Law Offi ce in Cairo who is not involved in the free to leave a university, she says, they are “authentic academic values” in not fulfi lling case, “I don’t think it’s fair.” No hearing date merely “agents of their institutions, rather her research duties. The $14,000 in damages, has been set yet for Siam’s appeal. than independent scientists.” the judgment states, is compensation for MUST officials did not respond to –JENNIFER CARPENTER “the loss of hope to the university and questions from Science. In a statement to Jennifer Carpenter is a writer in Toronto, Canada. CLIMATE CHANGE Downloaded from No Stopping the Collapse of West Antarctic Ice Sheet A disaster may be unfolding—in slow State University, University Park, referring result: In all but the most conservative melt motion. Earlier this week, two teams of sci- to the storm that ravaged the Caribbean and scenarios, a glacial collapse has already entists reported that Thwaites Glacier, a key- the U.S. East Coast in 2012. Alley was not started. In 200 to 500 years, once the glacier’s http://science.sciencemag.org/ stone holding the massive West Antarctic involved in either study. “grounding line”—the point at which the Ice Sheet together, is starting to collapse. In Where Thwaites Glacier meets the ice begins to fl oat—retreats past the ridge, the long run, they say, the entire ice sheet is Amundsen Sea, deep warm water burrows the glacier’s face will become taller and, like doomed. Its meltwater would raise sea levels under the ice sheet’s base, forming an ice a tower of blocks, more prone to collapse. by more than 3 meters. shelf from which icebergs break off. When The retreat will then accelerate to more than One team combined data on the recent melt and iceberg creation outpace fresh 5 kilometers per year, the team says. “On a retreat of the 182,000-square-kilometer snowfall farther inland, the glacier shrinks. glacial timescale, 200 to 500 years is the blink Thwaites Glacier with a model of the glacier’s According to the radar mapping released of an eye,” Joughin says. dynamics to forecast its future. In a paper this week in GRL from the European Remote And once Thwaites is gone, the rest of on page 735, they report that in as few as Sensing satellite, from 1992 to 2011 Thwaites West Antarctica would be at risk. on August 25, 2019 2 centuries Thwaites Glacier’s edge will Eric Rignot, a climate scientist at the Linchpin. recede past an underwater ridge now University of California, Irvine, and the Thwaites Glacier Weddell Sea stalling its retreat. Their models suggest ANTARCTIC lead author of the GRL study, is skeptical is connected PENINSULA that the glacier will then cascade into with its neigh- of Joughin’s timeline because the rapid collapse. The second team, writing bors in ways computer model used estimates of future in Geophysical Research Letters (GRL), that threaten a Bellingshausen WEST melting rates instead of calculations describes recent radar mapping of West wholesale col- Sea ANTARCTICA based on physical processes such as Antarctica’s glaciers and confi rms that lapse. changing sea temperatures. “These the 600-meter-deep ridge is the final Thwaites simulations ought to go to the next stage obstacle before the bedrock underlying Glacier and include realistic ocean forcing,” the glacier dips into a deep basin. Amundsen Sea he says. If they do, he says, they might Because inland basins connect predict an even more rapid retreat. Thwaites Glacier to other major glaciers Ross Sea Antarctic history confi rms the danger, in the region, both research teams say Alley says: Core samples drilled into its collapse would fl ood West Antarctica the inland basins that connect Thwaites with seawater, prompting a near-complete Glacier retreated 14 kilometers. “Nowhere Glacier with its neighbors have revealed loss of ice in the area over hundreds of years. else in Antarctica is changing this fast,” says algae preserved beneath the ice sheet, a hint “The next stable state for the West Antarctic UW Seattle glaciologist Benjamin Smith, that seawater has fi lled the basins within the Ice Sheet might be no ice sheet at all,” says co-author of the Science paper. past 750,000 years. That past fl ooding shows the Science paper’s lead author, glaciologist To forecast Thwaites Glacier’s fate, the that modest climate warming can cause the Ian Joughin of the University of Washington team plugged satellite and aircraft radar maps entire ice sheet to collapse, Alley says. “The SCIENCE (UW), Seattle. of the glacier’s ice and underlying bedrock possibility that we have already committed “Very crudely, we are now committed to into a computer model. In simulations to 3 or more meters of sea level rise from global sea level rise equivalent to a permanent that assumed various melting trends, the West Antarctica will be disquieting to many Hurricane Sandy storm surge,” says model accurately reproduced recent ice-loss people, even if the rise waits centuries CREDIT: K. ENGMAN/ CREDIT: glaciologist Richard Alley of Pennsylvania measurements and churned out a disturbing before arriving.” –THOMAS SUMNER www.sciencemag.org SCIENCE VOL 344 16 MAY 2014 683 Published by AAAS No Stopping the Collapse of West Antarctic Ice Sheet Thomas Sumner Science 344 (6185), 683. DOI: 10.1126/science.344.6185.683 Downloaded from ARTICLE TOOLS http://science.sciencemag.org/content/344/6185/683 RELATED http://science.sciencemag.org/content/sci/344/6185/735.full http://science.sciencemag.org/ CONTENT PERMISSIONS http://www.sciencemag.org/help/reprints-and-permissions on August 25, 2019 Use of this article is subject to the Terms of Service Science (print ISSN 0036-8075; online ISSN 1095-9203) is published by the American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. 2017 © The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. The title Science is a registered trademark of AAAS..
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