Scientists are increasingly alarmed about the stability of a vast system of ocean currents in the Atlantic, after new research suggested it could weaken far more severely than previously thought. The Atlantic Meridional Overturning Circulation (AMOC), which regulates climate across much of the globe, may slow by up to 59% by 2100, with potentially devastating consequences for weather systems as far away as the Indian subcontinent. The findings have particular significance for India, where hundreds of millions of people depend on the summer monsoon for their agricultural livelihoods and water supplies. Here is what to know. Think of the Earth’s oceans as having a massive, invisible conveyor belt. In the Atlantic Ocean, this system is scientifically known as the Atlantic Meridional Overturning Circulation. Warm, salty surface water from the tropics flows north towards Greenland. As it reaches the freezing Arctic, the water cools, becomes denser, and sinks several kilometres into the deep ocean.…