In a new paper, an international team led by scientists from Charles University, Czechia, has brought evidence linking widespread release of methane (CH₄)—a strong greenhouse gas—from the Greenland Ice Sheet (GrIS) to a warmer period 9–4 thousand years ago. CH₄ has been detected at retreating glacier margins worldwide, raising concerns about potential climate feedbacks associated with their widespread retreat, but this is the first time that a study has systematically investigated the whole margin of an entire ice sheet. The study is published in the journal Nature Geoscience.