CORRECTION Scientists scramble to harvest ice cores as glaciers melt
CORRECTION A previous version of the chart titled “An example of data collected in ice cores” inaccurately plotted CO2 and deuterium data on the X-axis resulting in a misleading timeline of events. The X-axis and accompanying captions and annotations have been corrected. Scientists are racing to collect ice cores - and the long-frozen records they hold of climate cycles - as global warming melts glaciers and ice sheets. But in some cases, it’s already too late.