The Guardian. Antarctic ice Antarctic ice melting at record rate, study shows

Summer ice is melting at a faster rate in the Antarctic peninsula than at any time in the last 1,000 years, new research has shown.

The evidence comes from a 364-metre ice core containing a record of freezing and melting over the previous millennium.

Layers of ice in the core, drilled from James Ross Island near the northern tip of the peninsula, indicate periods when summer snow on the ice cap thawed and then refroze.

By measuring the thickness of these layers, scientists were able to match the history of melting with changes in temperature.

Lead researcher Dr Nerilie Abram, from the Australian National University and British Antarctic Survey (BAS), said: "We found that the coolest conditions on the Antarctic peninsula and the lowest amount of summer melt occurred around 600 years ago.

In that decade, an El Niño event – a cyclical system of winds and ocean currents that can affect the world's weather – caused rapid thinning of glaciers in the west Antarctic.

The spike in temperature was little different from others that occurred in the 1830s and 1940s, which also saw prominent El Niño events.

"If we could look back at this region of Antarctica in the 1940s and 1830s we would find that the regional climate would look a lot like it does today, and I think we also would find the glaciers retreating much as they are today," said lead author Prof Eric Steig, from the University of Washington.

He said the same was not true for the Antarctic peninsula, the part of the continent closer to South America. Here, more dramatic changes were "almost certainly" a result of human-induced global warming.