5 November 2015, Washington Post, A controversial NASA study says Antarctica is gaining ice. Here’s why you should be skeptical. Late last week, a study published by NASA scientists in the Journal of Glaciology made the surprising claim that the gigantic continent of Antarctica is actually gaining ice, rather than losing it, to the tune of 82 gigatons (or billion metric tons) per year from 2003 to 2008. The study has drawn massive amounts of media attention — and no wonder. It contradicts numerous prior scientific claims, including a 2012 study in Science by a small army of polar scientists, a study from earlier this year in Earth and Planetary Science Letters (which found 92 gigatons of net losses per year) and this 2014 study in Geophysical Research Letters (160 gigatons of net losses per year). It also contradicts assertions by the leading consensus body of climate science, the U.N.’s Intergovernmental Panel on Climate Change, which stated in 2013 that Antarctica is “losing mass” and that this process is accelerating. That statement was itself based on multiple studies showing Antarctic ice loss. Not only does the new research fly in the face of all of this — if true, it also raises serious questions about our current understanding of sea level rise. If Antarctica is actually gaining ice, that means that a significant percentage of the current rise of the seas, estimated at roughly 3.22 millimeters per year by NASA itself, must be coming from elsewhere. (It takes 360 gigatons of ice to raise seas by 1 millimeter). No wonder, then, that a number of researchers have been quoted expressing skepticism about the new research, even as climate change doubters have had a field day — adding the study to an argumentative arsenal that previously included misleading claims about growing Antarctic sea ice. Read More here
Category Archives: Ecosystem Stress
4 November 2015, Stockholm Resilience Centre, Ecosystem management: Don’t fence me in. Managing ecosystems for predictable outcomes may backfire, new study warns When it comes to ecosystem goods and services, we humans tend to want to know what we are going to get: We want to have clean water every time we turn on the tap, beaches free of algae and bacteria, and robust harvests of crops, fish and fuel year after year. As a result, we try to manage the use of our ecosystems in ways that minimizes their variability. But a study published in the Proceedings of the National Academy of Sciences concludes that managing ecosystems for predictable outcomes is risky. In fact, more often than not, it backfires. Co-author and Centre science director Carl Folke explains: “Command-and-control management of ecosystems might make flows of ecosystem services predictable in the short term, but unpredictable and less resilient in the long term.” The pathology of short-term thinking. At the heart of the problem is the fact that while we can reduce variability in the short frame, variability doesn’t go away, it just goes somewhere else. Take for example our attempts at flood control on rivers. By installing levees, engineers are able to constrain flow and curb the fluctuations in water levels that once led to routine flooding of low-lying areas. These levees work so well that whole communities now exist in what were once floodplains. But, of course, the levees cannot remove all variability from the system. Sometimes a levee breaks or a river reaches levels higher than what the levee was built to withstand. The end result is a flood that is much more destructive than before. Steve Carpenter, lead author and director of the Center for Limnology at the University of Wisconsin-Madison explains: “For many years the river stays in the levee and everything is fine. However, every once in a while, it goes out and everything is worse.” Read More here
3 November 2015, The Conversation, As drought looms, the Murray-Darling is in much healthier shape – just don’t get complacent. Melbourne Cup Day is a significant day in the history of water policy in Australia. The first Tuesday in November 2006 saw the then Prime Minister John Howard intervene decisively in the growing drought crisis in the southern Murray-Darling Basin (MDB). Nine years on, the spectre of drought is back. The Murray Darling Basin Authority’s weekly reports show inflows into the River Murray (which can be seen as a proxy for the southern MDB) during the year to end September 2015 were the among the lowest on record. And the Bureau of Meteorology’s National Climate and Water Briefing last week suggests a warm and dry summer in prospect in the southern MDB, amid a still strengthening El Niño. Yet there are reasons to believe that these past nine years of stronger Commonwealth involvement have left the MDB much better placed to withstand an escalating drought. That said, there is no room for complacency, and continuing Commonwealth commitment is still needed if those hard-won gains are to be retained. Read More here
30 October 2015, Daily Science, Mass gains of Antarctic Ice Sheet greater than losses. A new study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers. A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers. The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice. According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008. “We’re essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of West Antarctica,” said Jay Zwally, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, which was published on Oct. 30 in the Journal of Glaciology. “Our main disagreement is for East Antarctica and the interior of West Antarctica — there, we see an ice gain that exceeds the losses in the other areas.” Zwally added that his team “measured small height changes over large areas, as well as the large changes observed over smaller areas.” Read More here