26th Dec 2025 - an AMOC collapse won't result in an overall cooling of the climate

Forecasts of colder winters after an AMOC collapse are reliant on climate model output to simulate the effects on such a complex atmospheric system. One well known example is in "Physics-based early warning signal shows that AMOC is on tipping course", where a climate model produced this figure below. As you can see, the winter climate cools to a ludicrous extent. London gets 15C colder in February, while this temperature drop exceeds 30C in the far north of Scotland.

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Then, if you factor in global warming, this change in temperature is drastically reduced. For example, in "European Temperature Extremes Under Different AMOC Scenarios in the Community Earth System Model", under 2C of climate change, very little change in January temperatures are left. Under 4C of climate change, all cooling is eradicated.

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In addition, the theory of a colder Europe becomes even more redundant when you factor in how models overestimate the cooling. A prime example is the Younger Dryas, where European summers warmed, shown in "Warm summers during the Younger Dryas cold reversal" and in "Younger Dryas deglaciation of Scotland driven by warming summers". However, in climate model simulations on a pre-industrial climate (which had a warmer Northen hemisphere, and less continental sea ice, so the cooling effect following an AMOC collapse should be reduced as a result of less albedo feedback), in the first study I mentioned in this post, summers still cool down, suggesting a climate model bias to overestimate the cooling that follows an AMOC collapse.

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This is the result of climate models not fully representing climate feedbacks that warmed European summers, shown in "European summer weather linked to North Atlantic freshwater anomalies in preceding years".

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