The Atlantic Meridional Overturning Circulation (AMOC) is a vast, north-south system of currents that carries warm surface water towards the Arctic and returns colder water thousands of miles south through the deep ocean. It is a key component of the Earth's climate system, influencing weather patterns and climate risks for the UK and north-west Europe. The AMOC is under pressure due to global warming, with scientists predicting a weakening of the current as the planet warms. This could lead to more extreme swings in the UK's weather, including colder winters, even as average global temperatures continue to rise. The AMOC includes the Gulf Stream and helps explain why Britain and north-west Europe are milder than their latitude would suggest. The AMOC's influence is close to home, as it helps shape the climate we live in and the weather we get. The AMOC is part of a vast heat-moving system that influences the climate far beyond the Atlantic. The AMOC is being stressed by the warming of the planet, with the more greenhouse gases humanity releases, the greater that stress becomes. Cutting emissions does not remove every uncertainty, but it reduces the pressure on a system no society can afford to push too far. The AMOC is still mysterious and capable of surprise, with scientists watching the ocean closely for warning signs. The AMOC has shifted before, and its behavior has changed in the past. The AMOC's future cannot yet be reduced to a simple story of imminent collapse, with uncertainty about how the ocean itself will behave. The AMOC's weakening could lead to more extreme weather patterns, including continued risk of extreme summer heat, greater exposure to cold winters, and more volatile weather generally. The AMOC's influence on the climate is complex and uncertain, with scientists debating the evidence and the risk of a tipping point. The AMOC's weakening could sharpen the temperature contrast between northern and southern Europe, one of the gradients that helps drive storms and other extremes. The AMOC's influence on the climate is a low-probability, high-impact risk, with scientists urging action on uncertainty.
