TIPPING POINT

Global warming 'past the point of no return

A record loss of sea ice in the Arctic this summer has convinced scientists that the northern hemisphere may have crossed a critical threshold beyond which the climate may never recover.
Scientists fear that the Arctic has now entered an irreversible phase of warming which will accelerate the loss of the polar sea ice that has helped to keep the climate stable for thousands of years.
Current computer models suggest that the Arctic will be entirely ice-free during summer by the year 2070 but some scientists now believe that even this dire prediction may be over-optimistic, said Professor Peter Wadhams, an Arctic ice specialist at Cambridge University.
"When the ice becomes so thin it breaks up mechanically rather than thermodynamically. So these predictions may well be on the over-optimistic side," he said.

Retreating glaciers worrying Greenlanders

The gargantuan chunks of ice breaking off the Sermeq Kujalleq glacier and thundering into an Arctic fjord make a spectacular sight. But to Greenlanders it is also deeply worrisome.
The frequency and size of the icefalls are a powerful reminder that the frozen sheet covering the world's largest island is thinning - a glaring sign of global warming, scientists say.
"We now have bream in our river, which we didn't have in the past because that fish is typical of warmer regions," said one. "On the one hand it may look like good news, but bream are predatory fish that prey upon fish eggs, often of rare kinds of fish."
Research also shows that populations of turbot, Atlantic cod and snow crab are no longer found in some parts of the Bering Sea, an important fishing zone between Alaska and Russia