Antarctica’s worrying retreat

Warming ocean water in Antarctica is melting much more underwater ice than previously thought, new research suggests— a discovery that could prompt a re-evaluation of predicted sea-level rises. Between 2010 and 2016, a team from the University of Leeds in the U.K. used satellite data to measure the surface height of about a third of the continent’s ocean-facing glaciers. This allowed them to monitor the “grounding line,” the point at which ocean, ice, and bedrock meet; when a glacier’s