The Atlantic meridional overturning circulation (AMOC), a system of ocean currents that carry warm water from the tropics into the North Atlantic and transport cold water from the northern to the southern hemisphere, is a fundamental mechanism for the regulation of Earth’s climate. The conveyor belt has collapsed in the past owing to natural factors. The most recent collapse played a key role in the last deglaciation. AMOC is now threatened by global warming, scientists have shown, and a new study has discovered the sequence of past breakdown events.