Scientists scramble to harvest ice cores as glaciers melt

Scientists are racing to collect ice cores - along with long-frozen records they hold of climate cycles - as global warming melts glaciers and ice sheets. Some say they are running out of time. And, in some cases, it’s already too late.

Late last year, German-born chemist Margit Schwikowski and a team of international scientists attempted to gather ice cores from the Grand Combin glacier, high on the Swiss-Italian border, for a United Nations-backed climate monitoring effort. In 2018, they had scouted the site by helicopter and drilled a shallow test core. The core was in good shape, said Schwikowski: It had well-preserved atmospheric gases and chemical evidence of past climates, and ground-penetrating radar showed a deep glacier. Not all glaciers in the Alps preserve both summer and winter snowfall; if all went as planned, these cores would have been the oldest to date that did, she said.