A climatic study warns that the Atlantic Meridional Overturning Circulation, known by its acronym AMOC, could partially collapse by the end of the century, sooner than previously expected. This is stated in a new study published by the journal Science in mid-April, which warns that there is a high probability (90%) that this crucial system for the planet will weaken and lose half of its strength by 2100.
This system is responsible for displacing immense quantities of water warm and salty from the tropics to the north of the planet and transferring deep waters in the opposite direction, managing to distribute the accumulated heat. The Corriente Canaria and the slope currents of the African continent are part of this system.
Its collapse, that is to say, the possibility that it considerably reduces its strength and that, therefore, it may not be able to transport these currents, could mean that the average temperature of the countries that make up Northwestern Europe fall sharply, according to what the State Meteorological Agency (Aemet) reported in 2024, while part of the heat that it should transport towards the north remains retained in the south.
The current study indicates that the slowdown of the AMOC will "strongly" influence the future Atlantic climates, but will also entail the displacement of the intertropical convergence zone, where the trade winds of the northern hemisphere coincide with those of the south. The research warns that this slowdown could cause widespread drought in the Sahel region, which will pressure the agriculture of Mauritania, Mali, Burkina Faso, Niger, and Chad and also put their food security at risk. A part of the people arriving at the archipelago through the migratory route to the Canary Islands come from Mauritania and Mali.
Among these climate projections, one of the most studied elements is the Atlantic Meridional Overturning Circulation, due to its "global impact". The latest climate models conclude that the AMOC "will decrease" throughout this century, but they do not agree on the magnitude of this decrease, which could even lead to its collapse. To address this uncertainty, this research has employed a somewhat "unusual" method in climate science: ridge regularized linear regression.
This scientific research addresses the discrepancies between the different climate projections developed to date, which predict that the AMOC would reduce its strength between 32 and 37%, compared to the loss of approximately half of its strength, that this new method proposes.
Readapt the adaptation plans
The climate adaptation and mitigation plans are based on this type of projections based on climate models that contemplate different scenarios, which depend directly on the capacity of States to stop emitting greenhouse gases that accelerate the climate crisis. However, climate projections take into account different variables and, depending on which variables are chosen, there may be "substantial differences" in the simulations.
With this scientific method, it is estimated that the weakening of this fundamental system for the planet will be "stronger" than what the average of the rest of scientific research projects.
Therefore, the research warns that a greater slowdown of the AMOC will entail "significant modifications" in climate projections for different regions of the world and the emergence of "additional risks" that must be considered.
Its impact in Canarias
Meanwhile, the Aemet explained two years ago that the AMOC had already suffered other historical collapses. At the same time, it pointed out that its current weakening became evident in the 19th century and accelerated throughout the 20th. Among the consequences of this loss of strength, it warned of the warming of the South Atlantic, by transporting a smaller amount of heat northward and these warm waters would remain trapped in the south. Which would also mean a cooling of the European continent, including Spain, and the Canary Islands, which would be influenced by high pressures over Europe and the intensification of the Canary Current.
The Canary Current and the slope currents of the African continent are part of this North Atlantic Meridional Overturning Circulation. A 2017 investigation carried out by the Universidad de Las Palmas de Gran Canaria and the Instituto Español de Oceanografía already showed that changes in the Canary Current influenced this complex system.
