14 January 2016, Science Daily, Study finds high melt rates on Antarctica’s most stable ice shelf. Melting rates found to be 25 times higher than expected. A new Scripps Institution of Oceanography at UC San Diego-led study measured a melt rate that is 25 times higher than expected on one part of the Ross Ice Shelf. The study suggests that high, localized melt rates such as this one on Antarctica’s largest and most stable ice shelf are normal and keep Antarctica’s ice sheets in balance. The Ross Ice Shelf, a floating body of land ice the size of France jutting out from the Antarctic mainland, continuously melts and grows in response to changes to both the ice sheet feeding it and the warmer Southern Ocean waters beneath it. For six weeks the researchers collected radar data to map changes in ice shelf thickness to understand the processes that contribute to melting at its base. The findings revealed dramatic changes in melt rate within less than a mile. The highest melting rates of more than 20 meters (66 feet) per year are thought to contribute to the rapid formation of channels at the base of the ice shelf, which can result from fresh water flowing out from lakes under the West Antarctica ice sheet. Shifts in subglacial drainage patterns change the location of these basal channels, which could impact the ice shelf’s stability by unevenly distributing the melting at the base. “The highest melt rates are all clustered at the start of a developing ice shelf channel,” said Scripps alumnus Oliver Marsh, a postdoctoral researcher at the University of Canterbury and lead author of the study. “The location of the melting strengthens the idea that freshwater from the local subglacial drainage system is responsible for the evolving ice shelf features.” Read more here
14 January 2016, The Guardian, Climate change disaster is biggest threat to global economy in 2016, say experts. Global warming heads top economists’ concerns for first time but large-scale forced migration seen as most likely risk to materialise. A catastrophe caused by climate change is seen as the biggest potential threat to the global economy in 2016, according to a survey of 750 experts conducted by the World Economic Forum. The annual assessment of risks conducted by the WEF before its annual meeting in Davos on 20-23 January showed that global warming had catapulted its way to the top of the list of concerns. A failure of climate change mitigation and adaptation was seen as likely to have a bigger impact than the spread of weapons of mass destruction, water crises, mass involuntary migration and a severe energy price shock – the first time in the 11 years of the Global Risks report that the environment has been in first place. The report, prepared by the WEF in collaboration with risk specialists Marsh & McLennan and Zurich Insurance Group, comes a month after the deal signed in Paris to reduce carbon emissions. The WEF said evidence was mounting that inter-connections between risks were becoming stronger. It cited links between climate change and involuntary migration or international security, noting that these often had “major and unpredictable impacts”. Espen Barth Eide, the WEF’s head of geopolitical affairs, said there was a risk of Europe fragmenting as a result of “people on the move”. Speaking at a press conference in London to launch the report, Eide said: “I am concerned about the continued support in national politics for keeping Europe together.” Read More here