“I personally think it’s very hard to say is going to happen in the next 50 years,” said Zhengyu Liu, atmospheric sciences director at the Ohio State University.

But in many ways, this study is a microcosm of the many challenges that come with trying to predict - and speak definitively about - how our planet will change in the future. It’s a striking study, and it can make us feel like catastrophe is not only looming but irreversible. “We were thinking that there's something wrong in what we're doing because we got estimates that are so off compared to the IPCC.”

“When we first got these results, we didn't believe them ourselves,” said Susanne Ditlevsen, a mathematician at the University of Copenhagen and co-author, with her brother Peter Ditlevsen, of the new paper. If it does, it would bring rapid changes to the world’s climate of a type that haven’t been seen in over 12,000 years. A new study, published Tuesday in Nature Communications, says otherwise: the AMOC, its authors say, will reach its “tipping point” by the middle of this century, and could collapse sometime between 20. What scientists haven’t agreed on, however, is when the AMOC might stop, though the latest report from the Intergovernmental Panel on Climate Change, or IPCC, predicted it should hold out through the end of the century. Scientists have long worried that what used to be a steady exchange of warm and cold water between the tropics and the North Atlantic is being disrupted by cold freshwater from melting Arctic ice, and could even shut down entirely, sending Northern Europe into a deep freeze and causing even more extreme heat to hit tropical regions. The ocean’s circulatory current, a system called the Atlantic Meridional Overturning Circulation, or AMOC, seems to be slowing down. For a while now, something weird has been happening in the Atlantic Ocean.

Fishing planet map