A hidden ocean change near Antarctica could have global consequences

The rapid decline of Antarctic sea ice since 2016 has triggered a dramatic shift in a crucial part of Earth’s climate system, scientists say. In a paper published Wednesday, researchers documented a sharp salinity increase in a vast layer of the Southern Ocean, extending from 2,300 to 4,000 feet deep and encircling Antarctica. The shift reverses decades of freshening and echoes ocean changes usually associated with major global climate shifts over millennia but is now happening in just a few yea