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AMOC stability and global warming speed research

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2026-10-17 15:38 UTC → 2026-10-22 11:24 UTC · added ~~removed~~

Researchers at Utrecht University have published findings in ‘Nature Climate Change’ regarding the stability of the Atlantic Meridional Overturning Circulation (AMOC). The study indicates that the speed of global warming and the rate of CO2 concentration growth are critical factors in determining whether this ocean current system collapses. Climate models suggest the AMOC may withstand significant warming if temperature rise is gradual; conversely, rapid warming poses a higher risk, with potential collapse at a 2.0 degrees Celsius threshold if CO2 increases at 2.5 or 5.0 ppm per year. This challenges previous estimates that placed the collapse threshold at roughly 4.0 degrees Celsius. New research suggests the AMOC functions as an oceanic ‘heat vent’ that regulates planetary temperature. As the circulation slows, the mixing process weakens, causing more heat to remain trapped within the ocean's interior. This is evidenced by a persistent ‘cold patch’ or ‘warming hole’ south of Greenland and Iceland, where temperatures have dropped nearly one degree Celsius since 1900 despite global warming. Warnings from the Alliance to Feed the Earth in Disasters (ALLFED) ~~warns that~~ indicate an AMOC collapse could ~~severely threaten~~ cause global ~~food security,~~ wheat, maize, and rice yields to fall by nearly one-fifth in certain countries, potentially driving global price spikes of up to 40 per cent. ~~Further observations from~~ Additionally, the University of Miami have identified a persistent weakening in the western component of the AMOC, adding to concerns that the system is at its weakest state in approximately 1,000 years. Evidence of a slowdown may already be underway, highlighted by a notable “cold patch” south of Greenland. In response to these risks, European nations are intensifying assessments. Iceland has classified an AMOC collapse as a ‘national security risk’. The Netherlands is evaluating impacts on flood protection systems, while Finland is studying risks to its energy and agricultural sectors. Additionally, the United Kingdom Bern has allocated £81 million toward research for early warning mechanisms to monitor the subpolar gyre and the Greenland ice sheet. Recent data from September 2026 shows Arctic sea ice reaching record lows, covering only 4.6 million km2. New modeling by Valentin Portmann et al., utilizing over 30 climate models, projects noted that marine heatwaves in the ~~AMOC~~ North Atlantic could ~~weaken by approximately 50% by the end of this century due~~ become significantly more extreme, with simulations suggesting some events could last up to ~~rising water temperatures and freshwater influx from melting ice and rain.~~ 579 days.

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