Newly uncovered history of a key ocean current carries a warning on climate
An international research team has used sediment cores from the planet’s roughest and most remote waters to chart the long-term history of the world’s most powerful ocean current, and its relationship to climate. Their key discovery: During past natural climate swings, the Antarctic Circumpolar Current has moved in tandem with Earth’s temperature, slowing down during cold times and gaining speed in warm ones―speedups that abetted major losses of Antarctica’s ice. The current is now speeding up, and the research suggests that this will continue as human-induced warming proceeds. That could hasten the wasting of Antarctica’s ice, increase sea levels, and possibly affect the ocean’s ability to absorb carbon from the atmosphere.