A new article in Nature Sustainability by Brenden Jongman and Jim Hall, published via The Conversation on 29 October 2026, reports that of 91 national adaptation plans submitted to the U.N. climate convention, only two even mention the Atlantic meridional overturning circulation (AMOC) — and neither sets out concrete action in response to its possible collapse.

The finding landed as Icelandic officials met to discuss what would happen if the current that circulates Atlantic waters weakened significantly or collapsed altogether.

Adaptation is normally built around steady, predictable trends — hotter summers, more variable rainfall.

The AMOC breaks that logic: it is a high-impact scenario whose likelihood is very hard to quantify, and if the current collapsed, some regions could experience climate change in the opposite direction to what they are preparing for, most notably colder winters in northwestern Europe.

The authors note that a full collapse is unlikely before 2100, but the near-total absence of AMOC from national planning means long-lived infrastructure investments are being stress-tested against only one plausible future.

phys.org reports that a recent study projected a 50% weakening of the AMOC by the end of the century under an intermediate emissions scenario, and that geological records show a near-complete shutdown around 17,500 years ago after the coldest period of the last ice age.

Attribution science is showing a parallel pattern on land: according to environment coastal & offshore, a study of September 2024's Storm Boris found that without anthropogenic climate change its precipitation would have been 6–9% lower, but flood peaks would have been 14–22% lower — impacts compounding well beyond the meteorological change itself.

Model experiments with an AMOC shutdown show an average 29% weakening of the West African monsoon and 19% weakening of the Indian summer monsoon, raising food and water insecurity risks, plus increased drought risk in Central America, West Africa and the Amazon, and effects on fisheries and sea level; a collapsed heat transfer could bring -20°C winter extremes to London.

Ocean circulation is already shifting in unexpected ways: ThePrint reports an IISc-led study in Nature Climate Change found Antarctic Intermediate Water — part of the AMOC system — reversed a decades-long freshening and began growing saltier around 2015, coinciding with record-low Antarctic sea ice.

The Nature Sustainability article outlines five practical steps: identify the investments and countries most exposed; stress-test key investments against AMOC-collapse scenarios; favor flexible, stage-built or upgradeable solutions; use sustained AMOC monitoring to inform adaptation decisions; and reassess global climate projections, since the AMOC influences how much carbon the oceans absorb.

Brazil's plan warns a shutdown could push the Atlantic rain belt southward and tip the Amazon toward collapse, while Ireland concludes no national plan can prepare for such tipping points. The authors stress this should not distract from cutting emissions or responding to impacts already happening.