Melting Mystery Solved: Why Ice Sheets Shrink Faster Than They Grow

A study reveals that warming more significantly impacts the firn layer on the Greenland Ice Sheet than cooling, complicating efforts to reverse melting through geoengineering.
Scientists have long understood from ice core research that melting an ice sheet is easier than refreezing it. A recent study published in The Cryosphere reveals part of the reason: the “sponginess” of ice.

The study uses a physics-based numerical model to assess the impacts of warming and cooling on firn, the porous layer between snow and glacial ice, over the entire Greenland Ice Sheet. Megan Thompson-Munson, a CIRES and ATOC PhD student, led the study alongside her advisors: CIRES Fellow Jen Kay and INSTAAR Fellow Brad Markle.