A 400-Year Climate Link Between the Indian and Pacific Oceans Is Breaking Down
A new Woods Hole Oceanographic Institution study finds that the long-standing climate connection between the Indian and Pacific Oceans is breaking down in an unprecedented way. Paleoclimate records dating to the 1600s show only major volcanic eruptions in the early 1800s disrupted this link before; researchers say today's shift is being driven by human-caused warming instead.
A new peer-reviewed study in Nature Communications from the Woods Hole Oceanographic Institution shows that the four-century-old climate connection between the Indian and Pacific Oceans is breaking down in a way researchers call exceptional. Using paleoclimate records from corals, tree rings and stalagmites reaching back to the early 1600s, plus climate model simulations, the team found the two ocean basins moved in step for most of that period, except during a series of major volcanic eruptions between 1810 and 1850. Lead author Shawn Wang and co-author Caroline Ummenhofer say the modern breakdown, observed since the 1980s, is being driven by human-caused greenhouse gas warming rather than volcanism, and is more exceptional than anything in roughly a thousand years of climate history. Because forecasters have long relied on this ocean coupling to anticipate rainfall and monsoon patterns, a continued breakdown could make some climate forecasting models less reliable.