The planet’s melting speed is already equal to that of the last deglaciation 10,000 years ago

10,000 square kilometer chunk of Hawaii-like ice vanished in the blink of an eye 11,000 years ago from a layer that covered the sea off Svalbard, In the Arctic.

According to a new study, this dramatic event was preceded by a fairly rapid melting of 2.5 kilometers of ice per year. This is parallel to current melting rates in Antarctica and Greenland and worries the scientists behind the study.

Measurements of the ice retreat in the Storfjorden Trench (the region in the Arctic Sea where the study was conducted) show that conditions until the 11,000-year-old event are what we are seeing today in Antarctica and Greenland. “It’s amazing. There are new studies published almost every week, which show that the retreat of the current ice caps is two to four kilometers per year and that it is accelerating, explains in a statement the professor of the Center for Arctic Gas Hydrate, Environment and Climate and first author, Tine Lander Rasmussen.

The last thaw, 20,000 to 10,000 years ago, it was a period of global warming coexisting with rapidly shrinking ice caps. But stating the real correlation between the two is not as straightforward as it sounds. The period in question was unstable from a climatic point of view and the large foundations were interrupted by the refreezing and the formation of new ice. Therefore, it has been difficult to establish the rate of ice retreat, relative to climate change.

“We studied the development of the ice sheet 20,000 / 10,000 years ago using marine sediment cores. All 12 nuclei have been collected from the region over the past 18 years and have been meticulously analyzed for different types of microfossils of single-celled organisms called foraminifera, ”says Rasmussen.

The biochemistry of foraminiferous fossils helps reconstruct the enormous amount of information about the state of the environment in prehistoric times. The sediments have been cut They represent periods of 30 to 70 years. More than 70 samples have been dated and analyzed.

“What we saw is that the ice cap started to retreat about 20,000 years ago, but it remains on a ridge of the fjord. Then, about 15,000 years ago, the temperatures of the atmosphere and the oceans warmed, affecting ocean circulation. Much of the ice cap is disappearing at the same time. At the start of the warm period of the Holocene, 11,000 years ago things really accelerated. We can no longer see evidence of an ice cap covering the ocean floor after this period, ”he said.

Extremely rapid periods of ice cap retreat are consistently correlated with periods of global warming of the oceans and temperature. This is reflected in the retreat of the ice caps from eight other fjord systems in northern Norway.

“This reinforces our hypothesis that an increase in ocean temperature and global warming is the direct cause of the chain of events that led to the extremely rapid disintegration of the ice sheet,” says Rasmussen. This gives some alarming perspectives on the current landscape. The great melting of the Holocene glacial maximum took 10,000 years to prepare. Today’s climate change is much faster.

“The final retreat from the ice cap of Storfjorden trough – he adds – it happened just as quickly in the outer parts as higher up in the depression. This means that as soon as the warmer ocean water entered the ice cap, it rose fairly rapidly inward from the edge of the pack ice. Inside the diaper itself. We see it happening in Antarctica today. The ruptures of Larsen A (1995), B (2003) and C (2017) are examples of this process ”.