What is the thermohaline circulation and could it really shut down?
A colossal ocean conveyor belt moves heat around the planet - and Greenland's melting ice threatens to switch it off with catastrophic consequences.
The answer
The thermohaline circulation is a global ocean conveyor belt driven by differences in water temperature and salinity. Warm surface water flows north in the Atlantic, cools near Greenland, becomes dense, and sinks 2 to 4 kilometers to flow south along the ocean floor. This Atlantic Meridional Overturning Circulation (AMOC) transports roughly 1.25 petawatts of heat northward, keeping Europe 5 to 10°C warmer than equivalent latitudes. A 2021 study in Nature Climate Change found the AMOC is at its weakest in over 1,000 years. Freshwater from melting ice sheets reduces salinity, weakening the sinking mechanism. A 2024 study suggested potential collapse could occur between 2025 and 2095, triggering severe cooling across Europe.
Source: Wikipedia
- thermohaline circulation
- AMOC
- climate change
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