Researchers from the COLDEX project have analyzed 3 million year old ice cores from Antarctica, finding that global cooling occurred even while atmospheric carbon dioxide levels remained relatively stable. This suggests that factors like ocean circulation and planetary albedo played a larger role in ancient climate shifts than previously thought. These findings challenge earlier estimates based on sediment proxies and provide a direct measurement of the Pliocene atmosphere. The data helps scientists better understand the complex interactions between greenhouse gases and natural Earth systems over geologic time.
