10 March 2016, Climate News Network, Antarctic techno-fix cannot slow rising seas. Pumping seawater onto the Antarctic landmass to form ice and stop sea levels rising stands little chance of success, scientists say. Sea level rise is likely to be a problem too big to handle. Geoengineers will not be able to magic away the rising tides, according to new research. In particular, they will not be able to pump water from the sea and store it as ice on the continent of Antarctica. That is because, unless they pump it enormous distances, that will only accelerate the flow of the glaciers and it will all end up back in the sea again, a study in the journal Earth System Dynamics says. Geoengineering is sometimes produced as the high-technology solution to the environmental problems of climate change: if humans don’t change their ways and start reducing greenhouse gas emissions, say the proponents of technofix, human ingenuity will no doubt devise a different answer. But, repeatedly, closer examination has made such solutions ever less plausible. Scientists have dismissed the idea that the melting of the Arctic can be reversed, have only tentatively conceded that technology could dampen the force of a hurricane, and have found that – instead of cooling the Earth – attempts to control climate change could either make things worse or seriously disrupt rainfall patterns. On balance, scientists believe that most of the big geo-engineering ideas won’t work. Deep freeze And now a team from the Potsdam Institute for Climate Impact Research has poured cold water on the idea of pouring cold water onto the ice cap. The idea is a simple one. Are sea levels rising 3mm a year because the world is warming? Then pump the sea high onto the Antarctic landmass where it will freeze and stay frozen for a millennium. But to be sure of that, say the Potsdam team, at least 80% of the water would have to be pumped 700 km inland. That would take more than 7% of the annual global primary energy supply just to balance the current rate of sea level rise.But even in a world recently committed to a warming of less than 2°C, the seas are going to go on rising. Sea levels could rise at least 40cms by the end of the century – or possibly 130cms, with devastating consequences for low-lying coastlines: rich megacities might be able to build defences, but the poorest communities would be swept away. Read More here
Category Archives: Antarctica
15 February 2016, Climate News Network, Warmer seas speed up Antarctic ice melt. New scientific studies provide a further warning of the increasing vulnerability of Antarctic glaciers to faster melting as temperatures rise in the Southern Ocean. European researchers have once again warned that the thinning of the Antarctic ice shelf means that the flow of glaciers on the frozen continent could accelerate, with a consequent rise in sea levels. They examine, in two separate studies, the increasingly precarious state of some of the ice shelf. When the shelf, consisting of ice floating on the ocean, melts, it makes no difference to sea levels. But the floating ice does have an effect on the land. It serves as a brake on the pace of glaciers on their journey down to the sea – and the combined impact of warmer atmospheres and warmer seas in the Southern Ocean are rapidly thinning much of the ice shelf. Johannes Fürst, a researcher at the University of Erlangen-Nuremberg’s Institute of Geography in Germany, and colleagues report in Nature Climate Change that they analysed years of ice thickness data from European Space Agency satellites and airborne measurements. Land-borne ice They calculated that only 13% of the total ice shelf area of Antarctica could be called “passive” ice − that is, it plays no role in buttressing or slowing the land-borne ice. But in the last 20 years, observers have measured the successive losses to large areas of the Larsen ice shelf off the Antarctic Peninsula, and these have resulted in an alarming acceleration of glacial flow on land, even though Antarctica remains the coldest continent on Earth. In some cases, the speed of flow has increased eightfold. “If the ocean temperature rises by more than 2°C compared with today, the marine-based West Antarctic ice sheet will be irreversibly lost”. Dr Fürst says: “In contrast to the situation in Greenland, the loss of inland ice in West Antarctica is not caused by melting. It is much too cold for that to happen. The decrease is due to the glaciers flowing into the sea at a faster rate than 20 years ago − what we call dynamic ice loss. Read More here
14 February 2016, BREITBART, Some 150,000 penguins died after a massive iceberg grounded near their colony in Antarctica, forcing them to make a lengthy trek to find food, scientists say in a newly-published study. The B09B iceberg, measuring some 100 square kilometres (38.6 square miles), grounded in Commonwealth Bay in East Antarctica in December 2010, the researchers from Australia and New Zealand wrote in the Antarctic Science journal. The Adelie penguin population at the bay’s Cape Denison was measured to be about 160,000 in February 2011 but by December 2013 it had plunged to an estimated 10,000, they said. The iceberg’s grounding meant the penguins had to walk more than 60 kilometres (37 miles) to find food, impeding their breeding attempts, said the researchers from the University of New South Wales’ (UNSW) Climate Change Research Centre and New Zealand’s West Coast Penguin Trust. “The Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out,” they wrote in the research published in February. Fast ice is sea ice which forms and stays fast along the coast. During their census in December 2013, the researchers said “hundreds of abandoned eggs were noted, and the ground was littered with the freeze-dried carcasses of previous season’s chicks”. Read more here
3 February 2016, Nature Communications, Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years. Past fluctuations of the West Antarctic Ice Sheet (WAIS) are of fundamental interest because of the possibility of WAIS collapse in the future and a consequent rise in global sea level. However, the configuration and stability of the ice sheet during past interglacial periods remains uncertain. Here we present geomorphological evidence and multiple cosmogenic nuclide data from the southern Ellsworth Mountains to suggest that the divide of the WAIS has fluctuated only modestly in location and thickness for at least the last 1.4 million years. Fluctuations during glacial–interglacial cycles appear superimposed on a long-term trajectory of ice-surface lowering relative to the mountains. This implies that as a minimum, a regional ice sheet centred on the Ellsworth-Whitmore uplands may have survived Pleistocene warm periods. If so, it constrains the WAIS contribution to global sea level rise during interglacials to about 3.3 m above present. Read More here