Melting ice in Antarctica slows ocean currents

The study, published in the journal Nature, shows how Earth’s network of ocean currents is driven in part by high-density, cold salty water moving toward the seafloor near Antarctica. As the ice sheet now melts and fresh water melts when it becomes sea, the water becomes less salty and becomes less dense, so the downward motion slows.

Scientists say ocean currents have been stable for thousands of years, but are now being disrupted by a warming climate, reports say BBC. According to the researchers’ modelling, the process will slow by more than 40 percent over the next 30 years if carbon dioxide emissions continue at the current rate.

Oceanography professor Matthew England tells the BBC it will be on a course that appears to be collapsing.

If the earth had two lungs, it would be one of them.

Great impact on marine life

According to the study, the slowdown may also reduce the ocean’s ability to absorb carbon dioxide from the atmosphere. If ocean circulation slows, water at the surface quickly reaches its capacity to absorb carbon dioxide without replacing it with unsaturated water from the depths.

The slowdown could have dire consequences for marine life and the environment in Antarctica itself.

The process takes nutrients that have sunk to the bottom when organisms die, to return them to the global ecosystem and fisheries, Dr Adele Morrison tells the BBC.

Another consequence could be that a snowball effect occurs, causing more ice to melt.

“It opens a path for warmer water that could cause increased melt, swelling it even more, introducing more meltwater into the ocean and slowing circulation even further,” says Adele Morrison.

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