New simulations have revealed that the world's strongest ocean current, the Antarctic Circumpolar Current (ACC), didn't start flowing overnight. The current, which is five times stronger than the Gulf Stream, formed 34 million years ago after new ocean passageways opened up as Australia and South America drifted northwards. However, the study found that a strong westerly wind needed to kick up first, and the ACC could fully develop when Australia had moved further away from Antarctica. Despite its importance in global climate, the ACC remains understudied due to its remote location. It also played a key role in stabilizing Earth's climate, transporting nutrients and water around Antarctica and keeping warmer waters away from the ice sheets. The findings were published in the Proceedings of the National Academy of the Natural Science.