February 8, 2011 | 11:41 AM | By

Arctic sea ice extent: How low can it go?

FILED UNDER: Ocean Change

Sea ice extent in the Arctic in January 2011 was the lowest for any January in three decades of monitoring. Just how much lower than usual? A picture is worth a thousand words.

Jesse Allen/NASA, NSIDC

January 2011 sea ice extent (white) compared to the median (most common) January sea ice extent for the period 1979-2009 (red line).

Observers have also noted an increase in the length of the sea ice melting season. Scientists point toward two contributing factors:

  1. Atmospheric conditions that pushed cold air south over North America and Europe and allowed warm air to sit over the Arctic.
  2. Warming due to reduced reflection of sunlight by dark ocean waters revealed when sea ice melts.

Both explanations are examples of the classic circular feedback loops that are so pervasive in climate science. Melting ice leads to Arctic warming, which sets up atmospheric conditions that hold warm air over the Arctic, which leads to further melting, which leads to more warming, which … you get the idea.

  • Mtreiber

    arctic ice has been recovering for the last three years from the so called record low in 2008. If you want detailed accurate information on arctic sea ice see WUWT sea ice page.

  • Mr. Neutron

    http://psc.apl.washington.edu/ArcticSeaiceVolume/images/BPIOMASIceVolumeAnomalyCurrent.png
    The Arctic sea ice *volume* has been shrinking for decades, and there’s been no recovery since 2007 (that was the record low sea ice extent, not 2008). Once the anomaly (difference between the expected, average value and the actual, current value) reaches -13.5 in September, say goodbye to summer Arctic sea ice. Any summer now…

    If you can’t handle the truth, read WUWT to avoid reality for awhile. Once the sh!t hits the fan, WUWT will go the way of Enron.com, but they appreciate your support, and the advertisers money, in the meantime.