11 November 2015, Climate News Network, West Antarctic ice cascades towards crisis. Scientists warn that continued ocean warming will lead to ice loss in the Amundsen Sea region that could raise sea levels by three metres. It wouldn’t take much to precipitate the complete collapse of the West Antarctic ice sheet, according to new research. Just a few more decades of ocean warming would be enough to destabilise the relatively small region of ice by the Amundsen Sea − starting a cascade of slipping and sliding that would tip enough ice into the ocean to raise sea levels by three metres. The loss of ice would continue for centuries. Two scientists at the Potsdam Institute for Climate Impact Research (PIK) in Germany report in the Proceedings of the National Academy of Sciences that they wanted to take a look at the long-term future of the mass of south polar ice that has been worrying researchers for decades. Planetary temperatures The West Antarctic ice sheet has already been pronounced as being at the point of no return. Scientists have calculated that, were the world ever to burn all its fossil fuels, thus increasing levels of atmospheric carbon dioxide and stoking up planetary temperatures, that would be enough to melt the entire Antarctic continent and raise sea levels by 60 metres. But one of those studies focused on what is happening now; the second looked thousands of years ahead. Read More here
Tag Archives: Antarctica
10 November 2015, Science Daily, Geophysics could slow Antarctic ice retreat. Gravitational effects, variations in Earth structure could damp rise in global sea levels. The anticipated melting of the massive West Antarctic Ice Sheet could be slowed by two big factors that are largely overlooked in current computer models, according to a new study. The findings, published online in Nature Communications, suggest that the impact on global sea levels from the retreating ice sheet could be less drastic — or at least more gradual — than recent computer simulations have indicated. Over the past year, numerous studies have warned that parts of the West Antarctic Ice Sheet are on the verge of a runaway retreat. Just last week a high-profile research paper forecast that this could lead eventually to a rise in global sea levels of as much as three metres. The authors of the new Nature Communications paper, however, focus on two geophysical elements that they say aren’t adequately reflected in computer simulations for this region: the surprisingly powerful gravitational pull of the immense ice sheet on surrounding water, and the unusually fluid nature of the mantle beneath the bedrock that the ice sits on. “The fate of the polar ice sheets in a warming world is a major concern for policy makers — and attention is rightly focused on the importance of restraining CO2 emissions and preparing for rising sea levels,” says lead author Natalya Gomez, an assistant professor of Earth and Planetary Sciences at McGill University in Montreal. “But our study shows that for Antarctica, in particular, computer models also need to take into account how gravitational effects and variations in Earth structure could affect the pace of future ice-sheet loss.” Read More here
6 November 2015, Renew Economy, Big step finally taken towards making your fridge and air-con climate friendly. It’s hard to imagine the rhetoric soaring to greater heights. “A great signal for Paris”,”a much needed shot in the arm for climate action”, “provide an example of successful international cooperation”, “provide critical momentum for the climate negotiations”, “a strong signal to the UNFCCC to adopt a robust agreement at COP 21”, “boosting global cooperation ahead of Paris to benefit the planet”… Expectations were almost palpable. “A singular opportunity for countries to take action on climate”,”would set the stage for an ambitious and durable global climate agreement”, “lay the foundation for a global agreement in Paris that will protect generations to come”, “demonstrate that governments around the world have the political will to take bold action to avert a climate catastrophe”, “potentially catalyse far-reaching action at Paris”… Stirring stuff indeed, but who’d have guessed what all the fuss was about? You’d be forgiven for missing the muted clamour anticipating a long overdue agreement on the need to respond to the science calling for international action on the world’s most powerful and rapidly growing greenhouse gases. In a much anticipated gathering of the global community of nations in Dubai over the past week, intense negotiations have been taking place. The ultimate goal of the talks, which began in 2008, is to amend the Montreal Protocol to formally address the need to address the alarmingly rapid rise of the hydrofluorocarbons, or HFCs, highly potent greenhouse gases used across the refrigeration and air conditioning industries. A recent NASA study reported to the meeting also confirmed that contrary to previous understanding HFCs do have a small yet significant effect on ozone depletion, a point poignantly underscored by the appearance of the third largest Ozone hole this year. Read More here
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