What comes to mind when you think of Antarctica? Far away, penguins, maybe a few scientists, and……ice. Antarctica is a continent located towards the Southern Pole and covered, completely, in ice. The ice has come and gone throughout history as the result of massive changes in climate and now, something is happening to it. The ice is depleting, though not as fast as the Arctic Ocean, and not quite the way you would think. And if we accept that it is depleting, what happens as the climate continues to change? What happens to our coastal cities when the sea levels rise? What happens to weather patterns in the Southern Oceans? Before we can answer those questions, we need to understand what’s going on in Antarctica right now.
Ice is Increasing?
Some of you may have heard that all this talk about global warming is a scam. Antarctic Ice is actually increasing! They’re all lying to us! Now that is partially true. Antarctica is gaining sea ice. But it’s losing land ice. How does that work? As land ice from the Antarctic ice shelves melts due to increasing temperatures, it spreads out into the ocean and then rises due to its low density and freezes. The land ice decreases and contributes to the increase in sea ice. The most recent estimate concludes that Antarctic land ice decreased by an average of 70 giga-tonnes per year, with the estimates beginning in 1992 and going to 2011 (King, 2013). The chart to the right shows monthly changes in Antarctic ice mass, in giga-tonnes, measured by NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites from 2003 to 2011 (NASA, nd.). In addition, none of this is due to melting on the surface, so it’s more difficult to understand. In East Antarctica, the ice is growing slightly, possible due to an increased and temporary snowy period predicted to come with the warming climate. In West Antarctica, a lot more melting is occurring around the edges due to the increasingly warmer ocean around it. The Southern Ocean has been warming at around 0.17 C per decade (LiveScience Staff, 2010). So is it increasing, kind of, but it’s much more complicated than that.
Conveyor Belt Theory
There’s another reason why Antarctica is not melting at anywhere near the rate of the Arctic Ocean, and it’s called the Ocean Conveyor Belt. This theory has been found to have some problems, due to over simplification of the processes, which is what we’re about to do. Basically, there is a very complex system called the Meridional Overturning Current, which the Gulf Stream is a part of, which picks up heat from the Southern ocean and brings it up to the Northern Atlantic. As it goes North, it cools and sinks through a process known as convection and then goes back down to the Southern Ocean. This helps Antarctica stay colder. Although, it may soon become more of a problem as the MOC may begin to be slowing, possible due to runoff from Siberian permafrost or the Greenland ice sheet due to global warming. This problem has not started to...