Why would a collapse of Antarctic deep ocean circulation be a global threat?

Humans depend on the life produced in the planet's oceans. But new scientific modelling shows the oceans' capacity to sustain those necessary marine resources faces a new threat – and very soon. A new Australian study has found the deep ocean circulation that forms around Antarctica could be headed for collapse over the next three decades, bringing with it significant implications for the oceans, marine ecosystems and the climate for centuries to come.