by Daniel Brouse
August 10, 2025
The AMOC (Atlantic Meridional Overturning Circulation) is one of the planet's most important climate engines, moving warm water from the tropics northward and sending cold, dense water back south at depth. It's also deeply intertwined with a giant climate feedback loop -- the kind that can trigger sudden, far-reaching changes once certain thresholds are crossed.
If the AMOC slows or stops, the effects won't be uniform, and they certainly won't be simple. Models suggest that in North America, especially the Northeastern United States, winters could turn brutally cold, even as summers become hotter than ever. While some wonder whether sea ice might return to the Arctic under these conditions, it's unlikely. The intensity of summer heat in a warming world would still prevent the reformation of stable, long-lasting ice cover.
Europe's Outlook
For Europe, the story changes with geography -- and the result is a continent split between chill and scorch:
Southern Europe (Spain, Italy, Balkans): Drier and hotter overall, with summer heatwaves growing even more extreme.
Eastern Europe: Alternating between harsh winter cold snaps and scorching summer heat, making seasonal predictability far more difficult.
Stormier Skies and Unstable Patterns
One of the most disruptive consequences of an AMOC collapse would be the atmospheric chaos it unleashes. Jet stream patterns could warp and meander, fueling stronger, more frequent winter storms barreling in from the Atlantic, while southern regions face prolonged drought.
Not an Ice Age -- But a Roller Coaster
Despite colder winters in the north, this isn't a return to the last glacial period. Rising greenhouse gas concentrations will still push global temperatures upward, offsetting some of the cooling. Instead, Europe could face a highly unstable climate -- bitterly cold and stormy in the north, scorching and drought-prone in the south -- a seasonal whiplash that challenges agriculture, infrastructure, and ecosystems alike.
* Our climate model -- which incorporates complex social-ecological feedback loops within a dynamic, non-linear system -- projects that global temperatures could rise by up to 9°C (16.2°F) within this century. This far exceeds earlier estimates of a 4°C rise over the next thousand years, signaling a dramatic acceleration of warming.
We analyze how human activities (such as deforestation, fossil fuel use, and land development) interact with ecological processes (including carbon cycling, water availability, and biodiversity loss) in ways that amplify one another. These interactions do not follow simple cause-and-effect patterns; instead, they create cascading, interconnected impacts that can rapidly accelerate system-wide change, sometimes abruptly. Understanding these dynamics is essential for assessing risks and designing effective climate adaptation and mitigation strategies.
Ignite a Domino Effect: Albedo, Brown Carbon, AMOC, Permafrost, Amazon Rainforest Dieback, Sea Level Rise Pulses, Hydroclimate Whiplash, and Arctic Sea Ice Brouse and Mukherjee (2025)