Arctic temperatures in 2015 were the warmest on record, according to a report published on Tuesday that furthered concerns about the negative effects of melting sea ice.

Temperatures in the Arctic were more than 2 degrees Fahrenheit warmer than average in 2015, according to the National Oceanic and Atmospheric Administration (NOAA) report. Some areas of the Arctic experienced temperatures more than 5 degrees warmer than average.

“The Arctic is warming twice as fast as other parts of the planet,” NOAA chief scientist Rick Spinrad warned during a press conference on Tuesday.

The higher-than-normal temperatures contributed to less sea ice in the Arctic, according to the report, compiled by some 70 authors from 11 countries.

Minimum sea ice extent in September 2015 was 29 percent less than average, and was the fourth lowest in satellite record, the report said. Maximum sea ice extent occurred 15 days earlier than average, and was 7 percent less than average.

The Chukchi Sea, northwest of Alaska, and Baffin Bay, off the west coast of Greenland, saw the largest warming trends, the report said.

“Extensive” melting in Greenland occurred over more than 50 percent of its ice sheet, the report added. Scientists have said melting on Greenland is a growing factor in rising sea levels that could threaten low-lying coastal areas and islands thousands of miles away.

Another consequence of sea ice loss is that previously covered water is exposed to more solar radiation, raising ocean temperatures — affecting everything from weather to marine life.

The report cited walruses as just one species affected by melting ice. “In the Pacific Arctic, vast walrus herds are now hauling out on land rather than on sea ice as it retreats far to the north over the deep Arctic Ocean,” the report said. In a haul out, large numbers of sea mammals such as seals and walruses temporarily leave the water to rest, mate or bear young.

The lack of sea ice reduces access to prey for walruses. Meanwhile, female walruses and their young, which typically use sea ice dozens of miles out to sea to keep them closer to prey, now have to hunt from shore, the report said.

“Because walruses will make use of terrestrial sites for haul-out, extinction due to climate change impacts on sea ice is unlikely to occur for this species. But, it is certain that land-based sites alone will not support the same number of walruses that the mixed seasonal use of sea ice and land has permitted in the past,” the NOAA said in its report.

These indicators show that the environmental system throughout the Arctic continues to be influenced by long-term warming trends, the report added.

Spinrad said the report “shows the importance of international collaboration on sustained, long-term programs that provide insights to inform decisions by citizens, policymakers and industry.”