Worrisome signs re ice melting at both poles.
From Nat Geo:
An "alarming rate" of melting in the Antarctic Peninsula has finally snapped the ice bridge that held the Wilkins Ice Shelf in place, experts say.
The 25-mile-long (40-kilometer-long) ribbon of sea ice that secured the Jamaica-size ice shelf (which is just out of view in the above pictures) to Antarctica had been "hanging by a thread" since August 2008 (above, top, in November 2008 in a European Space Agency satellite image).
On Saturday, April 4, the bridge broke at its weakest point (bottom)—at about 1,640 feet (500 meters) wide—and shattered into hundreds of small icebergs. The ice shelf, which is now exposed to the open ocean, is more vulnerable to breaking up, experts say.
"We've been watching it all summer, waiting for it to go, and bang—now it's gone," David Vaughan, a glaciologist for the British Antarctic Survey, told National Geographic News.
"It's the culmination of yet another ice shelf retreat that's been driven by [warming] climate," Vaughan said.
The Antarctic Peninsula has warmed 3 degrees Celsius (5.4 degrees Fahrenheit) since the 1950s, he said—"something that people should take note of."
and from BBC:
Arctic ice reached a larger maximum area this winter than in the last few years, scientists say, but the long-term trend still shows it declining.
The 30-year trend shows the maximum annual sea-ice cover, usually seen in March, is shrinking by 2.7% per decade.
Only 10% of the cover consists of relatively durable ice that has formed over more than two years, a record low.
Scientists from the US National Snow and Ice Data Center (NSIDC), say the thin ice is prone to summer melting.
"Thickness is important, especially in the winter, because it is the best overall indicator of the health of the ice cover," said NSIDC scientist Walt Meier.
"As the ice cover in the Arctic grows thinner, it grows more vulnerable to melting in the summer."
In the 1980s, thick multi-year ice made up 30-40% of the cover, the scientists say.
The summer minimum area is changing much faster than the winter maxima, shrinking by about 0.7% per year. Last year UK researchers showed that the ice has also markedly thinned in recent years.