Were Earth's Ancient Oceans Green?

A new study published in Nature Geoscience challenges our understanding of Earth's oceans. Researchers suggest that billions of years ago, the oceans were green, not blue! High iron dissolution from continental rocks led to iron-rich oceans, making green light dominant underwater. Early cyanobacteria adapted by evolving pigments that absorbed green light, resulting in a green ocean. This research reveals a fascinating chapter in Earth's history and hints at the possibility of future ocean color shifts.