Down to the Wire: Arctic Ice Close to Bottom (we hope..)
September 12, 2011
Arctic sea ice has melted to a level not recorded since satellite observations started in 1972 – and almost certainly not experienced for at least 8,000 years, say polar scientists.
Daily satellite sea-ice maps released by Bremen university physicistsshow that with a week’s more melt expected this year, the floating ice in the Arctic covered an area of 4.24 million square kilometres on 8 September. The previous one-day minimum was 4.27m sq km on 17 September 2007.
The German researchers said the record melt was undoubtedly because of human-induced global warming. “The sea-ice retreat can no more be explained with the natural variability from one year to the next, caused by weather influence,” said Georg Heygster, head of the Institute of Environmental Physics at Bremen.
If current trends continue, a largely ice-free Arctic in the summer months is likely within 30 years –that is up to 40 years earlier than was anticipated in the last Intergovernmental Panel on Climate Change(IPCC) assessment report.
The last time the Arctic was uncontestably free of summertime ice was 125,000 years ago, at the height of the last major interglacial period, known as the Eemian.
Below, the most recent graph from the US National Snow and Ice Data Center, (from 9/11/11) shows a slightly different picture, with ice loss seeming to bottom out. The NSIDC has not updated with any announcements in several days, and they may or may not agree with the U. of Bremen on a new record. Typical of the minor differences seen between this type data sets, the big picture remains very much the same. This week will probably be when ice hits bottom for the year. Stay tuned.