Unprecedented Arctic Heat Wave Melts 1% of Svalbard’s Ice

During the summer of 2024, six weeks of exceptional heat resulted in significant ice melt on Svalbard, an island in the Arctic. By summer’s end, 1% of the archipelago’s land ice had vanished, contributing to a global sea level rise of 0.16 mm.

“It was incredibly startling,” said Thomas Schuler from the University of Oslo, Norway. “This wasn’t just a minor record; the melt was nearly double the previous highs.”

Over half of Svalbard is covered in ice. Snowfall during winter contributes to the ice, while summertime sees glacial currents flowing into the ocean and surface, resulting in ice retreat.

Schuler’s team utilizes a combination of field measurements, satellite imagery, and computer simulations to assess changes in the total ice mass of the archipelago.

Since 1991, summers have typically seen the melting of Gigatonnes of ice. However, four of the last five years have recorded new highs in summer ice loss. Last summer alone, approximately 62 Gigatonnes melted, predominantly due to surface melting, not ice flowing into the ocean.

In 2024, Schuler and his colleagues observed land rising by a record 16mm at one location, consistent with predictions of ice loss.

This extraordinary melting results from record high air temperatures. The average August temperature reached 11°C (52°F), compared to about 7°C (45°F) in recent decades. This extreme phenomenon stemmed from warm ocean temperatures and persistent weather patterns bringing warm winds from the south, coupled with a dramatic increase in global warming.

While such severe summer heat is currently rare, climate models predict that as global temperatures rise, similar events will become more common. Indeed, even under low emissions scenarios, over half of the summers leading to 2100 could surpass this temperature threshold.

Schuler’s team has yet to predict future ice loss under various emission scenarios. Although winter snowfall is expected to increase slightly as the atmosphere becomes more humid, it will not be sufficient to counterbalance the significantly larger summer melting.