The world’s glaciers may contain less water than previously believed, a new study has found, suggesting that freshwater supplies could peak sooner than anticipated for millions of people worldwide who depend on glacial melt for drinking water, crop irrigation and everyday use.

The latest findings are based on satellite images taken during 2017 and 2018. They are a snapshot in time; scientists will need to do more work to connect them with long-term trends. But they imply that further global warming could cause today’s ice to vanish in many places on a shorter timeline than previously thought.