Greenland has had a quite a year. For the first time in its history, rain fell at its summit. In August, it experienced one of the latest-occurring melt events in recent memory. This also became the third year with major melting events in the past decade.By the end of the melt season, the ice sheet lost more ice than it gained — for the 25th year in a row.

“The long-term past two decades have shown us the incredible wrongness in calling ‘glacial pace’ something slow,” said Marco Tedesco, a research professor at the Lamont-Doherty Earth Observatory at Columbia University.

Greenland lost a net total of 166 gigatons of ice from September 2020 through August 2021. Overall, this loss is on par with recent decades — but how the world’s largest island arrived at that final number is not.

“2020/21 was a comparably ‘normal’ year. The new normal, that is,” wrote Martin Stendel, a polar researcher at the Danish Meteorological Institute, in an email. “But that does not mean it was good in this sense.”

The island experienced anomalous swings from intense melting to unusual snowfall from a former hurricane. While the annual snowfall accumulation was healthy, ice loss from iceberg calving and ocean melt was the highest since at least satellite records began in 1986.

“When we see instability like this, this switch from a lot of accumulation to a lot of melting to a lot of accumulation to a lot of melting, it’s really a signal of the system that is looking for a way to be stable again,” said Tedesco, who also serves as an adjunct scientist at the NASA Goddard Institute for Space Studies. “The message of instability that Greenland is sending is terrible.”

This year’s activity over Greenland has many researchers concerned for a not-too-distant future.