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
Tag Archives: oceans
19 October 2015, The Conversation, The race to fish: how fishing subsidies are emptying our oceans. Fish numbers are rapidly dwindling globally, and fishery subsidies are one of the key drivers behind this decline. In 2009, these subsidies totalled about US$35 billion, creating incentives for fishers around the world to increase their catch. But this short-term “race to fish” is jeopardising the long-term environmental, social, and economic security that fisheries offer us all. My group at the University of British Columbia recently cast our net into the troubling waters of fishery subsidies, to see how this ship might be turned around. Overfishing: a major issue facing our oceans Fish numbers are rapidly dwindling globally, and fishery subsidies are one of the key drivers behind this decline. In 2009, these subsidies totalled about US$35 billion, creating incentives for fishers around the world to increase their catch. But this short-term “race to fish” is jeopardising the long-term environmental, social, and economic security that fisheries offer us all. My group at the University of British Columbia recently cast our net into the troubling waters of fishery subsidies, to see how this ship might be turned around. Overfishing: a major issue facing our oceans According to the recently released World Wildlife Fund Living Blue Planet Report, our oceans are in a bad state. Climate change, habitat destruction, and deep-sea mining are wreaking havoc on marine biodiversity. But overfishing is in a league of its own. The WWF report found that population numbers of utilised fish (those species used by humans for subsistence or commercial purposes) have fallen by half in the four decades from 1970 to 2010. A full 90% of fish stocks globally are now classified as either overexploited or fully exploited. Common seafood choices such as tuna, shrimp, whiting, and salmon are among the worst affected. According to the recently released World Wildlife Fund Living Blue Planet Report, our oceans are in a bad state. Climate change, habitat destruction, and deep-sea mining are wreaking havoc on marine biodiversity. But overfishing is in a league of its own. The WWF report found that population numbers of utilised fish (those species used by humans for subsistence or commercial purposes) have fallen by half in the four decades from 1970 to 2010. A full 90% of fish stocks globally are now classified as either overexploited or fully exploited. Common seafood choices such as tuna, shrimp, whiting, and salmon are among the worst affected. Read More here
12 October 2015, Washington Post, Why the Earth’s past has scientists so worried about the Atlantic Ocean’s circulation. In the last month, there’s been much attention to a cool patch in the North Atlantic Ocean, where record cold temperatures over the past eight months present a stark contrast to a globe that is experiencing record warmth. And although there is certainly no consensus on the matter yet, some scientists think this pattern may be a sign of one long-feared consequence of climate change — a slowing of North Atlantic ocean circulation, due to a freshening of surface waters. The cause, goes the thinking, would be the rapidly melting Greenland ice sheet, whose large freshwater flows may weaken ocean “overturning” by reducing the density of cold surface waters (colder, salty water is denser). If cold, salty waters don’t sink in the North Atlantic and flow back southward toward Antarctica at depth, then warm surface waters won’t flow northward to take their place. The result could be a significant change to northern hemisphere climate, as less ocean-borne heat reaches higher latitudes. Read More here
8 October 2015, TomDispatch, Welcome to a New Planet Climate Change “Tipping Points” and the Fate of the Earth By Michael T. Klare. Not so long ago, it was science fiction. Now, it’s hard science — and that should frighten us all. The latest reports from the prestigious and sober Intergovernmental Panel on Climate Change (IPCC) make increasingly hair-raising reading, suggesting that the planet is approaching possible moments of irreversible damage in a fashion and at a speed that had not been anticipated. Scientists have long worried that climate change will not continue to advance in a “linear” fashion, with the planet getting a little bit hotter most years. Instead, they fear, humanity could someday experience “non-linear” climate shifts (also known as “singularities” or “tipping points”) after which there would be sudden and irreversible change of a catastrophic nature. This was the premise of the 2004 climate-disaster film The Day After Tomorrow. In that movie — most notable for its vivid scenes of a frozen-over New York City — melting polar ice causes a disruption in the North Atlantic Current, which in turn triggers a series of catastrophic storms and disasters. At the time of its release, many knowledgeable scientists derided the film’s premise, insisting that the confluence of events it portrayed was unlikely or simply impossible. Fast forward 11 years and the prospect of such calamitous tipping points in the North Atlantic or elsewhere no longer looks improbable. In fact, climate scientists have begun to note early indicators of possible catastrophes. Read More here