Recent reports of record-setting snowfall in Antarctica suggest that after decades of steadily losing ice, Antarctica’s ice cover could finally be reversing course. That would be welcome news, and it’s easy to think the change means ice sheets are no longer melting. But in the lifespan of an ice sheet, these reversals are unlikely to have a major impact in coming centuries.
“It seems like this is a good sign,” WHOI glaciologist Catherine Walker says of the increased snowfall. But despite the recent addition, the overall trend is that the ice sheet is shrinking. In part, it’s a question of time scales. The “mass balance of an ice sheet is comprised of processes that occur over hundreds to thousands of years,” she says. Compare that to a one- or two-year change, and it quickly becomes apparent this snowfall is likely a temporary feature.
Ice sheets build up over millennia through snowfall, which then melts at the edges. Over time, the weight of new snow compacts deeper layers into dense sheets of ice that slowly spread across the land like a pancake. The edges of that pancake eventually reach the Antarctic coastline, where glaciers slide into the sea, melt, and calve icebergs, processes that release large quantities of fresh water into the ocean…
Source: Woods Hole Oceanographic Institution | Ocean Learning Hub (2025)
