Planet Earth Online: Pine Island Glacier, the largest single contributor to sea-level rise in Antarctica, has started shrinking, say scientists. The work, published in Nature Climate Change, shows the glacier's retreat may have begun an irreversible process that could see the amount of water it is adding to the ocean increase five-fold. 'At the Pine Island Glacier we have seen that not only is more ice flowing from the glacier into the ocean, but it's also flowing faster across the grounding line - the boundary between...