The deep-water flows which drive ocean currents could decline by 40% by 2050, a team of Australian scientists says. Dr Adele Morrison, who contributed to the report, explained that as ocean circulation slows down, water on the surface quickly reaches its carbon-absorbing capacity and is not then replaced by non carbon-saturated water drawn to the surface from greater depths. "[It's] stunning to see that happen so quickly," said climatologist Alan Mix from Oregon State University, a co-author of the latest Intergovernmental Panel on Climate Change (IPCC) assessment