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 within the Earth's climate system, contributing to the UK's long-term climate risks. 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 is part of a vast heat-moving system that influences the climate far beyond the Atlantic. The UK sits in the middle of that exchange, with heat released from the Atlantic feeding into the air above it, helping fuel storms, steer winds and influence the pressure systems that reach north-west Europe. If the ocean changes, the weather can change too. A severe weakening, or collapse, of the AMOC could bring colder, drier winters to the UK and north-west Europe even as the planet as a whole continues to heat up. The AMOC helps shape rainfall and temperature patterns far beyond Europe, affecting harvests, water supplies and the livelihoods of hundreds of millions of people. 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 science does not offer a neat ending. It offers probabilities, warnings, caveats and arguments between experts who weigh the same clues differently. But they agree on what is driving the risk. The AMOC is being stressed by the warming of the planet. The more greenhouse gases humanity releases, the greater that stress becomes. The AMOC is still moving, still mysterious, and still capable of surprise. Whether the AMOC is simply weakening, or being pushed towards something more abrupt, remains unresolved. But the safest response is already clear. The AMOC is a key component within the Earth's climate system, contributing to the UK's long-term climate risks. 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.
