Sea ice breaking up in spring. Near Kulusuk, Greenland.

(steve_is_on_holiday/Getty Images)

At a Glance

Only about 20 percent of sea ice completes its typical Arctic journey before melting.Two decades ago, 50 percent of newly formed sea ice completed the journey.

Thanks to global warming, only about 20 percent of sea ice born in Russia's shallow seas ever makes it past the "nursery" without melting, a new study says.

Two decades ago, more than made a lengthy journey from the nursery off the Arctic coast of Russia to the central Arctic Ocean. There, it joins the Transpolar Drift and pushes out of the Arctic toward the Greenland Sea via the Fram Straight, between Greenland and Svalbard. Today, 80 percent of the ice melts before completing the journey, according to a study published Tuesday in Scientific Reports.

Considered the "nursery" of Arctic sea ice, Russia's shallow marginal seas — the Barents Sea, Kara Sea, Laptev Sea and East Siberian Sea — consistently produce new sea ice during the winter because of the extremely low temperatures that can drop to minus 40 degrees Fahrenheit.

A strong offshore wind propels the newly formed ice toward the central Arctic Ocean where it is carried off by the Transpolar Drift. In two to three years, the ice eventually makes its way to and out of the Fram Strait, where it typically melts. Today, only about 20 percent of the ice floes make it through the entire journey.

The shallow Russian shelf or marginal seas of the Arctic Ocean are broadly considered to be the ‘nursery’ of Arctic sea ice: in winter, the Barents Sea, Kara Sea, Laptev Sea and East Siberian Sea constantly produce new sea ice.

(Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research)

Researchers with the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research say the findings suggest the world is one step closer to having ice-free summers in the Arctic.

The researchers came to their conclusions using satellite data from 1998 to 2017 to monitor and analyze sea ice movement.

"Our study shows extreme changes in the Arctic: the in the Kara Sea, Laptev Sea and East Siberian Sea is now so rapid and widespread that we're seeing a lasting reduction in the amount of new ice for the Transpolar Drift," lead author Thomas Krumpen, a sea-ice physicist at the Alfred Wegener Institute, said in a press release.

Krumpen notes that the ice that does reach the Fram Straight today tends to form in the open waters of the central Arctic Ocean rather than in the marginal seas.

"What we're witnessing is a major transport current faltering, which is bringing the world one major step closer to a sea-ice-free summer in the Arctic," he said.

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Typically, ice formed along Russia's coast picks up important nutrients, algae and sediments and carries it though the Arctic. With more ice forming in the central Arctic, fewer nutrients, algae and sediments are being transported, which could permanently alter biogeochemical cycles and ecological processes in the Arctic Ocean, the researchers say.

In addition, ice that does make it out of the Fram Straight is 30 percent thinner than it was 15 years ago.

"The reasons: on the one hand, rising winter temperatures in the Arctic and a melting season that now begins much earlier; on the other, this ice is no longer formed in the shelf seas, but much farther north. As a result, it has far less time to drift through the Arctic and grow into thicker pack ice," Krumpen said.

Thinner ice also means it travels faster on the Transpolar Drift. Researchers had hoped the speeding up would make up for the decline in ice, but this new study suggests the ice is melting too fast to make up for the increase in ice speed.