‘Ninety percent of ice flowing to the sea from the Antarctic ice sheet, and about half of that lost from Greenland, travels in narrow, fast ice streams measuring tens of kilometres or less across. Stemming the largest flows would allow the ice sheets to thicken, slowing or even reversing their contribution to sea-level rise.” John Moore, a British glaciologist holding dual appointments at Lapland and Beijing Normal universities, had a big idea a few years ago. The big ice-streams are moving faster and faster because the oceans are warming, and warm currents are eating away at the underside of …