Shrinking of Arctic Ice Pole

1 October 2007

Arctic Sea Ice Shatters All Previous Record Lows

Diminished summer sea ice leads to opening of the fabled Northwest Passage

This is a press release from the National Snow and Ice Data Center (NSIDC), which is part of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder.

Media Relations Contact:Stephanie Renfrow, NSIDC: srenfrow@nsidc.org or +1 303 492-1497 (se habla Español)

Data: from MODIS satellite. Credit: National Snow and Ice Data Center.

Arctic sea ice during the 2007 melt season plummeted to the lowest levels since satellite measurements began in 1979. The average sea ice extent for the month of September was 4.28 million square kilometers (1.65 million square miles), the lowest September on record, shattering the previous record for the month, set in 2005, by 23 percent (see Figure 1). At the end of the melt season, September 2007 sea ice was 39 percent below the long-term average from 1979 to 2000 (see Figure 2). If ship and aircraft records from before the satellite era are taken into account, sea ice may have fallen by as much as 50 percent from the 1950s. The September rate of sea ice decline since 1979 is now approximately 10 percent per decade, or 72,000 square kilometers (28,000 square miles) per year (see Figure 3).

Figure 1: This image compares the average sea ice extent for September 2007 to September 2005; the magenta line indicates the long-term median from 1979 to 2000. September 2007 sea ice extent was 4.28 million square kilometers (1.65 million square miles), compared to 5.57 million square kilometers (2.14 million square miles) in September 2005. This image is from the NSIDC Sea Ice Index. See high-resolution version

From National Oceanic and Atmospheric Administration