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, and its weakening could have significant implications for the UK and north-west Europe. The AMOC is under pressure due to global warming, and scientists are concerned that it could weaken sharply or even collapse, leading to more extreme weather patterns, including colder winters, even as average global temperatures continue to rise. The AMOC helps shape the climate we live in and the weather we get, and its weakening could have far-reaching consequences for rainfall and temperature patterns far beyond Europe. The AMOC has shifted before, and there is evidence that it is already weakening, with a strange patch of cooling in the North Atlantic and changes in how salty the water is. The AMOC could reach a tipping point, where the weakening would begin to feed on itself, leading to a self-amplifying process that would be difficult to stop. However, not all scientists read the evidence the same way, and there is uncertainty about how close the system is to a threshold and how much weight to give to each kind of evidence. The safest response is already clear: cutting emissions reduces the pressure on the AMOC and helps prevent its weakening. The AMOC is a mysterious and complex system, and its future remains unresolved. However, the evidence suggests that it is under stress due to global warming, and action is needed to reduce the risk of its weakening and collapse.
