Human-induced warming disrupts centuries-old climate link between Indian and Pacific oceans

Scientists from the Woods Hole Oceanographic Institution analyzed paleoclimate archives and model simulations to trace the relationship between the tropical Indian and Pacific oceans back to the early 1600s. Their work confirms that the two basins have been tightly coupled for most of the last four centuries, except for a notable break between 1810 and 1850 linked to a series of large tropical volcanic eruptions. Recent observations indicate that since the 1980s the Indian Ocean’s behavior has diverged from the Pacific’s pattern, a shift the authors attribute to human-driven greenhouse-gas emissions.

Lead author Shawn Wang and co-authors Caroline Ummenhofer and Delia Oppo argue that this modern decoupling is “exceptional” compared with natural variability. The study, funded by the U.S. National Science Foundation and published in Nature Communications, highlights that weakening ocean links could undermine climate forecasts that rely on historic oceanic interactions.