Sea ice levels are approaching a new record this year, which unfortunately is a negative one. The National Snow and Ice Data Center (NSIDC) reported that the levels have fallen bellow the 2005 minimum, approaching the 2007 record low. With just a few weeks left before the melt season is over, the tendency remains crystal clear: the ice sea levels continue their negative trend that best illustrates the past decade.

Sea ice covers 7 percent of world’s ocean water, or approximately 25 million square kilometers (9,652,553 square miles) and mostly concentrates in Earth’s polar regions. Arctic sea ice is known to have suffered a thinning process, and according to computer models, the ice cover could completely disappear in summer time by the 2080s (NOAA).

In summertime, the Arctic ice begins to melt in mid-June. The layer that does survive is known as multi-year ice, and covers about half of the Arctic ice. Multi-year ice can reach a maximum of 3 meters in thickness. First-year ice is usually thicker than 30 centimeters, but it does not survive the summer melt season.

The sea ice extent reached a minimum in 2005, the second-lowest level known to date: 5.32 million square kilometers (2.05 million square miles). In 2007, the sea ice levels reached an all-time low, and this year, we can expect another negative record, perhaps even worse than last year.

According to NSIDC, the most recent retreat in sea ice reflects melt in the Chukchi Sea off the Alaskan coast and the East Siberian Seas off the cost of eastern Russia. On August 27, 2008, the Arctic sea ice extent was 5.26 million square kilometers (3.02 million square miles), a decline of 2.06 million square kilometers (795,000 square miles) since the beginning of the month.

By comparison, the values of the daily sea ice extent this year were very similar to the values of 2005. However, following the melt season, the differences began to show: in early August 2005, the decline in sea ice began to slow, while in 2008, the declined has kept a steady pace.

In 2007, Arctic sea ice reached the lowest level since the satellite measurements began in 1979, totaling 4.28 million square kilometers (1.65 million square miles) in September, 23 percent lower than in 2005, and 39 percent lower than in 1979.

According to NASA satellite observations made public in March this year, the Arctic region was dealing with an increase in the sea ice towards the beginning of the year, due to weather conditions, but at the same time, perennial sea ice continued to shrink, which was a clear sign that global warming had already started to set in.

NASA’s observations concluded that the perennial ice covered only 30 percent of the Arctic, compared to the 50-60 percent it used to cover in the past. Compared to two centuries ago, the oldest sheet of ice that used to cover 20 percent of the Arctic and lasted for about 6 years covered only 6 percent of the Arctic in 2008.

NASA warned that we must make a clear distinction between short-term effects, which revealed an improvement in ice level, but not as a lasting phenomenon, and the long-term effects of temperatures rising, which contribute to an Arctic meltdown.

The situation is critical, as Arctic sea ice has a very important role in moderating global climate. Over the past three decades, both the thickness and summer sea ice extent in the Arctic region have shown a dramatic decline, which is consistent with observations of a warming Arctic.

NSIDC Senior Scientist Mark Serreze explained: “Computer projections have consistently shown that as global temperatures rise, the ice sea cover will begin to shrink. While a number of natural factors have certainly contributed to the overall decline in sea ice, the effects of greenhouse warming are now coming through loud and clear.”