Wilder winds are altering currents; the sea is releasing CO2, and ice is melting from below. The Southern ocean’s Antarctic Circumpolar Current extends up to two miles deep and is up to 1,200 miles wide. It has kept the world from warming even more by drawing deep water from the Atlantic, Pacific and Indian oceans and pulling it to the surface. There, it exchanges heat and carbon dioxide with the atmosphere before being dispatched again on its eternal round trip. Without this upwelling, the world would be even hotter. As the world warms the unceasing winds driving the upwelling are getting stronger potentially releasing more CO2, by bringing to the surface more of the deep water that’s held this carbon locked away. The Southern Ocean is also getting warmer. Some of this upwelling water, already relatively warm, flows beneath ice shelves on the Antarctic coast that help keep the continent’s ice sheets from reaching the sea more quickly. That’s already adding to sea level rise. Over time it could contribute much more, potentially swamping coastlines in the next century and beyond.
www.nytimes.com/interactive/2021/12/13/climate/antarct