Ancient Air, Fresh Clues: 1.4-Billion-Year-Old Bubbles Rewrite Early Earth's Climate
Scientists extracted tiny air inclusions from 1.4‑billion‑year‑old salt crystals to directly measure Earth’s ancient atmosphere. The CO₂ levels were far lower than prior estimates, challenging the idea of a CO₂‑rich early atmosphere and suggesting a cooler, methane‑influenced climate that persisted under a faint Sun, with implications for the rise of life and hints for exoplanet habitability.