Arctic Ice Recedes Yet Again, Scientists Say

The Arctic ice shelf has melted for the fourth straight year to its smallest area in a century, driven by rising temperatures that appear linked to a buildup of greenhouse gases, scientists said Wednesday.

Scientists at NASA and the National Snow and Ice Data Center, which have monitored the shelf by satellite since 1978, say the total Arctic ice in 2005 covers the smallest area since they began measuring.

Both the satellite evidence and shipping data, which go back many years, show this is the least amount of Arctic ice in at least a century, the groups’ report says.

As of Sept. 21, the sea ice area had dropped to 2.05 million square miles, the report says.

From 1978 to 2000, the area averaged 2.70 million square miles, the report says. The melting trend has shrunk Inuit hunting grounds and endangered polar bears, seals and other wildlife.

The report warns that if the melting continues at the current rate, the summertime Arctic could become ice-free before the end of the century. That echoes last year’s report by the Arctic Council, an eight-nation group that published the findings of 250 experts.

“It’s increasingly difficult to argue against the notion that at least part of what we are seeing in the Arctic, in terms of sea ice, in terms of warming temperatures ... is due to the greenhouse effect,” said Mark Serreze, a research scientist at the national snow center.

Many scientists say greenhouse gases, including carbon dioxide released mainly from cars and utility smokestacks, cause global warming by trapping solar heat in the atmosphere.

Scientists say the Arctic is warming faster than the rest of the globe because water or bare ground soaks up more heat than ice and snow. That means the melting can spur even warmer temperatures and more melting.