Published on February 21st, 2017 | by James Ayre0
Antarctic Sea Ice Now At Lowest Levels Since Record-Keeping Began (Preliminary NSIDC Figures)
February 21st, 2017 by James Ayre
Antarctic sea ice is now at its lowest extent since record-keeping on the subject began in 1979, based on preliminary satellite data from the US National Snow and Ice Data Center (NSIDC).
Sea ice extent in Antarctica typically reaches its low point for the year towards the end of February, before the Southern Hemisphere begins heading into autumn and sea ice extent begins growing again. As of February 13th, though, sea ice extent in Antarctica totaled only 2.287 million square kilometers (883,015 square miles) — making for a new record low extent. (February 14th apparently then saw a lower extent, 2.224 million square kilometers.)
— Zack Labe (@ZLabe) February 13, 2017
The previous record low Antarctic sea ice extent of 2.290 million square kilometers (884,173 square miles) occurred around February 27, 1997.
The news is noteworthy as until very recently “climate change deniers” have used Antarctic sea ice extent (which was fairly stable in recent times) as an argument against the existence of recent and ongoing global temperature rise (lazy, and unconvincing to those who aren’t just looking for a cheap shot, but it was used this way nonetheless).
“It’s a new record, and it might actually go a little bit further south yet this summer,” commented Jan Lieser, a marine glaciologist with the Antarctic Climate and Ecosystems Cooperative Research Centre in Hobart.
Here’s more from the Sydney Morning Herald:
“In the south, each day this summer the extent of frozen sea has been the lowest recorded for that date since 1979, when satellite data was first collected.
“Dr Lieser said the lowest extent to date was last Tuesday, when it fell to 2.224 million square kilometres — an area roughly the size of Tasmania less than the previous low in 1997. It comes just two years after scientists reported a record high ocean sea ice extent.
“He said a fall in sea ice coverage brings a feedback effect. White ice reflects heat, but darker water absorbs it. Whenever there is less sea ice, more heat goes into the ocean, delaying freezing the following winter and likely contributing to a further reduction over time.”
While future fluctuations are to be expected, rather than there simply being a yearly decrease in extent for the foreseeable future, the new record does seem to suggest that sea ice in Antarctica is now on a terminal decline.