Melting Ice and Cold Shivers

One of the most fearsome aspects of climate change are the feedback-loops.
Once a certain point is reached, something else gets damaged, which does more damage until the next thing goes plop.

And one of those things is the ice on the poles.

The ice plays an important role in climate change, not only because it reflects most of the sun’s warmth back into space. Even more important is the “engine” role the icy parts of the world play in the oceans.

Water cools down, sinks down and moves around the globe. It warms up again, rises and moves on until it finally reaches the poles again. The most famous of those streams is the gulf stream that temperates Europe by several degrees. But those streams also move oxygen and plankton. If the streams break down, it would be a disaster for maritime life.

Computer models have predicted that this could happen when the warmer climate melts more ice then before and the fresh/salt water balance is disturbed. But that was only a computer model. Until now.

The new research, based on ocean measurements off the coast of East Antarctica, shows that melting Antarctic glaciers are indeed freshening the ocean around them. And this, in turn, is blocking a process in which cold and salty ocean water sinks below the sea surface in winter, forming “the densest water on the Earth,” in the words of study lead author Alessandro Silvano, a researcher with the University of Tasmania in Hobart.

If the process of Antarctic bottom water formation is being impaired, at least in some regions, then it would be a Southern Hemisphere analogue of a process that has already caused great worry and drawn considerably more attention — a potential slowdown of the overturning circulation in the North Atlantic Ocean, thanks to freshening of the ocean from the melting of Greenland.

It is really troublesome that of all things the worst predictions about climate change are so often confirmed or even found to be underestimates.

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