Although they may often seem like a haven of peace and tranquility, or we may believe that their fury comes only in the form of surface storms and gigantic waves, the oceans hide much more within their depths; specifically, currents that regulate the direction of warm and cold water, influencing not only the seas but also the Earth's general climate. This is known as the Atlantic Meridional Overturning Circulation (AMOC), a large system of ocean currents (including the Gulf Stream) that, like a sort of conveyor belt, moves water from the tropics to the North Atlantic. However, the AMOC could be in serious danger: a study published in the journal Nature Communications indicates that it could collapse at any time from 2025 onwards due to continued greenhouse gas emissions, which, according to its authors, could cause serious damage to the global climate. But what exactly would the consequences be if these currents stopped? Temperature Fluctuations The AMOC is one of the planet's most important climate tipping points: even though it is underwater, it has the power to abruptly and rapidly shift the Earth's entire climate system into an irreversible state. Related News standard No Extreme heat waves will be longer, more intense, and more frequent due to climate change Elena Calvo The episodes experienced in recent weeks would be "almost impossible" if the burning of fossil fuels were to end, scientists warn. Recent studies indicate that some of the strongest and most abrupt climate fluctuations in the past, such as the so-called "Dansgaard-Oeschger events" during the last ice age, some 12,000 years ago, were caused by the collapse and subsequent recovery of the AMOC. During those past events, the Northern Hemisphere experienced average temperature fluctuations of between 10 and 15 degrees in just a single decade. Much greater, therefore, than the current changes of 1.5 degrees in a century. The strength of the AMOC, however, has only been continuously monitored since 2004, and those observations have shown that it is indeed weakening, although longer records would be needed to assess the magnitude of this trend. More extreme hurricanes and storms According to some experts, the weakening of these currents and the warming of some maritime areas can already be seen in more numerous and powerful hurricanes. Also, the change in Atlantic temperatures affects weather patterns in Europe, such as the trajectory of storms. For example, some tropical cyclones are no longer limited to the tropics but are traveling through subtropical waters, closer to our latitudes, in places like the Canary Islands and the Azores, where they previously did not reach. Rising sea levels Previous work has also shown that the slowing of the AMOC exacerbates sea level rise on the US East Coast in cities like New York and Boston. Not only that: the European heatwave of the summer of 2015 has been linked to the record-breaking cold in the North Atlantic that year. MORE INFORMATION news No A spectacular image shows how a planet is formed news No Sex and space tourism: the consequences of relationships beyond Earth Even so, it should be noted that there is no absolute consensus on the real state of the AMOC and its future, especially given its recent comprehensive monitoring and the deep and complex mechanisms that scientists still do not fully understand.
