Antarctic Sea Ice Shows Big Reduction

Sea ice reduction in the Arctic has long been considered as a strong indicator of global warming.  As the volume of sea ice is reduced the reflective impact of sea ice covered waters is decreased.  This leads to more heat absorption and warming.  The Arctic was the poster child for the feedback loop that global warming was creating - less sea ice = more heat = less sea ice = more heat......

The Antarctic has been different.  The massive belt of sea ice that surrounds the continent of Antarctica has actually grown over much of the the last 40 years when it has been closely scrutinized.  This was clearly the case until 2014, when scientist observed the beginning of a substantial and prolonged reduction in the area of sea ice at the bottom of the world.

Antarctic and Arctic Sea Ice Changes - Antarctic above, Arctic below.  From PNAS proceedings.

The plunge in the average annual extent means Antarctica lost as much sea ice in four years as the Arctic lost in 34 years. The cause of the sharp Antarctic losses is as yet unknown and only time will tell whether the ice recovers or continues to decline.

“The Arctic has become a poster child for global warming,” Parkinson said, but the recent sea ice falls in Antarctica have been far worse. She has tracked Antarctic sea ice for more than 40 years. “All of us scientists were thinking eventually global warming is going to catch up in the Antarctic,” she said.

Arctic sea ice reduction is influencing global weather patterns right now.  The Antarctic sea ice losses are more disconnected from global weather patterns, so it will take time to assess whether this is a transient event or, if the reduction trend continues, what will the global weather implication be.