The Southern Ocean may be less of a carbon sink than we thought

FRIEND OR FOE? The water around Antarctica absorbs a lot of the carbon that humans produce. But hints that the ocean’s cleanup capacity may be falling short are coming in from CO2-measuring floats being dropping from ships. Hannah Zanowski/SOCCOM Project/Flickr (CC BY 2.0)
The water surrounding Antarctica may be belching more CO2 than it takes in

By Alexandra Witze | ScienceNews

The vast stretch of icy water that separates Antarctica from other continents is a dark mystery to most people. Polar explorer Ernest Shackleton, one of the few who have been to the Southern Ocean, regarded its storm-wracked seas with fear and awe. After ice floes trapped and crushed the three-masted Endurance in 1915, Shackleton made an epic rescue attempt, sailing 1,300 kilometers to bring help to his stranded crew. He crossed the Southern Ocean’s waters in a small open boat, threatened by what he called “uprearing masses of water, flung to and fro by Nature in the pride of her strength.”

Yet this remote, tempestuous ocean also benefits humankind. Scientists estimate that each year, the Southern Ocean slurps up more than 40 percent of the carbon dioxide that people release by burning fossil fuels for electricity, heat and transportation. That makes the ocean a powerful support system for slowing the buildup of heat-trapping greenhouse gases in the atmosphere. The more carbon this immense body of water takes up, the less accumulates in the atmosphere to warm the planet.

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