In brief
Only two of 91 national adaptation plans mention the Atlantic current that could freeze Europe
Just two of the 91 national adaptation plans submitted to the UN climate convention mention the Atlantic Meridional Overturning Circulation (Amoc), and neither sets out concrete action in response to its possible weakening or collapse, according to a study in Nature Sustainability.
The Amoc carries warm surface water north and cold deep water south, redistributing heat across the planet. It is weakening: one recent study projected a 50% decline by 2100 under an intermediate emissions scenario, and the current shut down almost entirely around 17,500 years ago. Modelling a shutdown produces winter cold extremes of −20°C in London, a 29% weakening of the West African monsoon and a 19% weakening of the Indian summer monsoon.
Brazil's plan devotes a box to warning that a shutdown could push the Atlantic rain belt southwards, tipping the Amazon towards collapse. Ireland, which relies on the current for its mild climate, concedes that "reliance solely on adaptation may prove insufficient" and that no national plan can prepare for such tipping points.
The authors argue the risk falls outside standard adaptation practice: it is high-impact but hard to quantify, and north-west Europe could face changes opposite to those it is planning for. Their five steps are to identify exposed investments, stress-test them against collapse scenarios, favour staged and flexible solutions, fund ocean monitoring, and reassess global warming projections. Icelandic officials have already met to discuss the scenario.
