Icebergs near GreenlandCavan Images/Alamy A collapse in the Atlantic Meridional Overturning Circulation (AMOC) would be catastrophic, bringing “ice age” winters to Europe, raising sea levels in North America and disrupting vital monsoons in Africa and Asia. But there is a sliver of good news: a climate-driven collapse of the AMOC might not be permanent. The AMOC could weaken significantly under rising global temperatures over the coming decades, but it could recover its strength just as quickly if global cooling occurs. “There’s a very linear relationship between the global mean temperature and the AMOC response,” says Chuncheng Guo at the Danish Meteorological Institute. “When people talk a...