Oldest ever ice offers glimpse of Earth before the ice ages

VIENNA— Samples of eerie blue glacial ice from Antarctica are a staggering 6 million years old, scientists announced last week, doubling the previous record for Earth’s oldest ice. The ice opens a new window on Earth’s ancient climate—one that isn’t exactly what scientists expected. Bubbles in the ice trap air from the Pliocene epoch, a time before the ice ages when the planet was several degrees warmer than today and carbon dioxide (CO 2 ) levels may have been just as high as they are now. But an initial analysis of the bubbles suggests CO 2 levels were rather low in the late Pliocene and only sank slightly between 2.7 million and 1 million years ago as the Pliocene ended, the ice ages began, and Earth headed toward a dramatic climate shift that caused ice ages to grow longer and deeper. The results are preliminary, stresses Ed Brook, a geochemist at Oregon State University (OSU) and leader of the U.S. Center for Oldest Ice Exploration (COLDEX), which presented the discovery last week here in multiple talks at the European Geophysical Union General Assembly. But if even a tiny drop in CO 2 can kick off a major climate change, Brook adds, “you know, we probably care about that.” Finding ice this old is “ fantastic,” says Eric Wolff, a paleoclimatologist at the Uni...
Source: ScienceNOW - Category: Science Source Type: news