ANCHORAGE (US): Arctic Ocean sea ice has melted to the second lowest minimum since satellite observations began, according to scientists at the US National Snow and Ice Data Centre.

Sea ice melt recorded on Monday exceeded the low recorded in 2005, which had held second place. With several weeks left in the melt season, ice in summer 2008 has a chance to diminish below the record low set last year, according to scientists at the National Snow and Ice Data Centre.

Environmental groups said the ice melt was another alarm bell warning of global warming. "It's an unfortunate sign that climate change is coming rapidly to the Arctic and that we really need to address the issue of global warming on a national level," said Christopher Krenz, Arctic project manager for Oceana.

"This is not surprising but it is alarming," said Deborah Williams, a former Interior Department special assistant for Alaska. "This was a relatively cool summer, and to have ice decrease to the second lowest minimum on record demonstrates that global warming's ongoing impact is profound."

The National Snow and Ice Data Centre, based at the University of Colorado, reported the ice Monday melted below the 2005 minimum of 5.3 million square kilometers set on September 21 that year. Exact figures will be released on Wednesday.

Through the beginning of the melt season in May until early August, daily ice extent for 2008 closely tracked the values for 2005, the centre said.

In early August 2005, the decline began to slow. In August 2008, however, the decline has remained steadily downward at a brisk pace.