In late July, a study published in Nature Communications warned that a critical ocean system that brings warm water up the North Atlantic, also known as the Atlantic Meridional Overturning Circulation (AMOC), was at risk of collapse by 2095 for want of drastic emissions cuts. While AMOC was already known to be at its slowest in 1600 years, the latest research ushers in a much closer time estimation for a collapse between 2025 and 2095, with a central estimate of 2057. If proven correct, this scenario could see temperatures drop by 5 to 10 degrees in Europe, with devastating consequences for life as we know it. The Conversation sat down with physicist Peter Ditlevsen and his sister, the statistician Susanne Ditlevsen, to unpack findings that have stirred controversy in some quarters.
Your study understandably attracted much media attention, with some of the coverage conflating a collapse of the Gulf Stream with a collapse of AMOC. What did you make of this at the time?
Susanne Ditlevsen: I think there are two aspects to this question. One is that the general public might confuse the Gulf stream and the AMOC and, in a certain sense, that’s just wording. So there is a current that brings warm water up and this is in danger of collapsing – whether we call it the AMOC or the Gulf Stream even though the Gulf Stream is something different in a certain sense doesn’t matter if it’s just a question of wording.
