American geoscientists have discovered 2.7 million-year-old ice — the oldest ever by 1.7 million years, researchers announced at the annual Goldschmidt conference in August. The sample was drilled from Antarctica’s Allan Hills “blue ice” area, where unusually old glacial ice is closer to the surface, making it more accessible.
Trapped bubbles can offer snapshots of past carbon dioxide and methane levels. This latest sample reveals Earth’s climate history beyond a critical benchmark when, 1 million years ago, glacial cycles shifted from 40,000- to 100,000-year periods. Understanding temperature and greenhouse gas shifts through those ice ages could also offer insights into Earth’s future climate.