Along Antarctica’s west coast near the Amundsen Sea, great white glaciers the size of U.S. states slowly slide into the ocean. In the early ’80s, scientists dubbed it the continent’s “weak underbelly” after learning that ice here — which helps hold back the entire West Antarctic Ice Sheet — is anchored below sea level.

If oceans warmed, this unfortunate topography could cause rapid and irreversible retreat. In decades past, glaciologists had assumed these ancient features advanced and retreated on epic time scales — not in human lifetimes.

Ever since, climatologists have been spellbound watching the rapid changes. We now know that melting the whole West Antarctic Ice Sheet could cause 15 feet of global sea level rise. And that’s galvanized the scientific community, leading to a new $50 million joint U.S.-U.K. project to predict ice melt rates.