A big chunk of Greenland's ice cap breaks off as Arctic shifts to new climate regime

A big chunk of Greenland's ice cap, estimated to be some 110 square kilometres, has broken off in the far north east Arctic, which scientists say is evidence of rapid climate change.

The news comes as scientists reported that the long-frozen region is already shifting to an entirely new climate regime, marked by escalating trends in ice melt, temperature rise and rainfall days. The new research was published Monday in the journal Nature Climate Change.

Those findings, climate scientist Laura Landrum said, were "unnerving."

The section of the Greenland ice cap, part of the Spalte glacier, broke off the fjord called Nioghalvfjerdsfjorden, which is roughly 80 kilometres long and 20 kilometres wide, the National Geological Survey of Denmark and Greenland said Monday. The glacier is at the end of the Northeast Greenland Ice Stream, where it flows off land and into the ocean.

Annual end-of-melt-season changes for the Arctic's largest ice shelf in Northeast Greenland are measured by optical satellite imagery, the survey known as GEUS said.

It shows that the area losses for the past two years each exceeded 50 square kilometres. Since 1999, the ice shelf has lost 160 square kilometres, an area nearly twice the size of New York's Manhattan Island. 

"We should be very concerned about what appears to be progressive disintegration at the Arctic's largest remaining ice shelf," said GEUS professor Jason Box.

At the edge of the ice blanketing part of the Arctic Ocean, the ice on Monday looked sickly. Where thick sheets of ice once sat atop the water, now a layer of soft, spongy slush slid and bobbed atop the waves.

From the deck of a research ship under a bright, clear sky, "ice pilot" Paul Ruzycki mused over how quickly the region has changed since 1996, when he began helping ships spot icebergs and navigate between them.

"Not so long ago, I heard that we had 100 years before the Arctic would be ice free in the summer," he said. "Then I heard 75 years, 25 years, and just recently I heard 15 years. It's accelerating."

Sea ice records breaking

With climate change driving up Arctic temperatures, the once-solid sea ice cover has been shrinking to stark, new lows in recent years.

This year's minimum, still a few days from being declared, is expected to be the second-lowest expanse in four decades of record-keeping. The record low of 3.41 million square kilometres was reached in September 2012 after a late-season cyclonic storm broke up the remaining ice.

"We haven't gone back at all to anything from 30 to 40 years ago," said climatologist Julienne Stroeve at the National Snow and Ice Data Center in Boulder, Colo. And as climate change continues, scientists say the sea ice is unlikely to recover to past levels.

Sea ice coverage minimums in particular, are now about 31 per cent lower than in the 1980s, when satellite observations began. The ice has also lost about two-thirds of its bulk, as much of the thicker ice layer built up over years has long since melted away. The current ice regime actually began about two decades ago, the study found.

This vanishing of sea ice also contributes to the region's warming, as the icy white expanse is replaced by patches of dark water that absorb solar radiation rather than reflecting it back out of the atmosphere. The process, referred to as Arctic amplification, helps to explain why the Arctic has warmed more than twice as fast as the rest of the world over the last four decades.

More rain than snow

The polar north will also likely see more days of rain rather than snow, which would further eat into the ice.

For the new research, Landrum and her colleague Marika Holland at the National Center for Atmospheric Research analyzed sea ice, air temperature and precipitation data since 1950 to project climate scenarios up to the end of the century. They used computer simulations in the analysis and assumed the world's release of greenhouse gas emissions would continue at a high trajectory.

All three variables — sea ice, temperatures and rainfall — are now being measured well beyond the range of past observations. That makes the future of the Arctic more of a mystery.

"The new climate can't be predicted by the previous climate," Landrum explained. "The year-to-year variability, the change in many of these parameters, is moving outside the bounds of past fluctuations."

Back in the Arctic Ocean aboard Greenpeace's Arctic Sunrise research ship, biologist Kirsten Thompson of the University of Exeter said the new study was important in underlining "how fast and how profoundly the Arctic is changing."

For Thompson, that means big change for the region's wildlife, from polar bears and insects to the whales she studies.

"All their distributions are changing," she said. "We might find in the Arctic there will be winners and losers," as new species enter the region and compete with indigenous animals.

"Other species certainly will not be able to survive in the future."

Last week, Ruth Mottram, an ice scientist at the Danish Meteorological Institute in Copenhagen, said, the ice sheet this year has again "lost more ice than has been added in the form of snow."

"What is thought-provoking is that if we ... had seen this meltdown 30 years ago, we would have called it extreme. So in recent years, we have become accustomed to a high meltdown."

In August, a study showed that Greenland lost a record amount of ice during an extra-warm 2019, with the melt massive enough to cover California in more than 1.25 metres of water.