Arctic sea ice shrank to the second-lowest extent since records began over four decades ago, federal scientists said Monday, prompting renewed warnings about the climate crisis.
The minimum ice cover for 2020 was likely reached on Sept. 15, scientists at the National Snow and Ice Data Center (NSIDC) announced. On that date, ice measured 1.44 million square miles (3.74 million square kilometers). That coverage is 135,000 square miles (350,000 square kilometers) more than the lowest extent of ice recorded in 2012.
"The Earth just rang another alarm bell in the climate emergency," said Arlo Hemphill, senior oceans campaigner at Greenpeace USA.
The near record comes amid what NSIDC director Mark Serreze described as "a crazy year up north, with sea ice at a near-record low, 100-degree F heat waves in Siberia, and massive forest fires."
The finding also marks the continuation of a trend: the 14 lowest minimum Arctic sea ice extents were all recorded in the last 14 years, scientists noted.
"The year 2020 will stand as an exclamation point on the downward trend in Arctic sea ice extent. We are headed towards a seasonally ice-free Arctic Ocean, and this year is another nail in the coffin," said Serreze.
“The year 2020 will stand as an exclamation point on the downward trend in Arctic sea ice extent. We are headed towards a seasonally ice-free Arctic Ocean and this year is another nail in the coffin.” We've called the likely #Arctic sea ice minimum extent: https://t.co/xfjgaJCPSZ pic.twitter.com/t5DBMJ5o5e
— National Snow and Ice Data Center (@NSIDC) September 21, 2020
NASA, which supported the analysis, explained further:
A Siberian heat wave in spring 2020 began this year's Arctic sea ice melt season early, and with Arctic temperatures being 14 to 18 degrees Fahrenheit (8 to 10 degrees Celsius) warmer than average, the ice extent kept declining. The 2020 minimum extent was 958,000 square miles (2.48 million square kilometers) below the 1981-2010 average of yearly minimum extents, and 2020 is only the second time on record that the minimum extent has fallen below 1.5 million square miles (4 million square kilometers).
"The extent of summer sea ice in the Arctic can impact local ecosystems, regional and global weather patterns, and ocean circulation," NASA noted, and shared this video to accompany the new analysis:
Serreze added that the ice "is shrinking in the summer, but it's also getting thinner."
"You're losing extent, and you're losing the thick ice as well," he said. "It's a double whammy."
Laura Meller, Greenpeace Nordic Oceans Campaigner, said the new data is cause for concern.
"The rapid disappearance of sea ice is a sobering indicator of how closely our planet is circling the drain," Meller said in a statement from onboard the Greenpeace ship Arctic Sunrise. "As the Arctic melts, the ocean will absorb more heat, and all of us will be more exposed to the devastating effects of climate breakdown."