For the last 3000 years the Beaufort Sea region has had “permanent sea ice.”

According to a new study, there was “no sea ice” in the Arctic’s Beaufort Sea from 11,700 to 8200 years ago.

During this period, summer sea surface temperatures (SSTs) averaged ~7°C, varying up to 9.6°C.

“The Early Holocene (11.7−8.2 ka) is characterized by relatively higher sea surface temperature, lower salinity, and no spring/summer sea ice until 8.5 ka on the Beaufort Sea slope.”

Modern summer SSTs average 3°C in this region, which means SSTs are at least 4°C colder than they were during the Early Holocene.

From approximately 7000 to 5000 years ago (the Mid Holocene), seasonal sea ice was present in this Beaufort Sea region.

For the last 3000 years, sea ice has been present year-round.

“…permanent sea-ice cover on the slope after 3 ka.”

Image Source: Santos et al., 2026

This new study echoes a 2020 study (Wu et al.) indicating the Beaufort Sea had “dominantly ice free conditions” and SSTs were over 4°C warmer than today during the Early Holocene.

Image Source: Wu et al., 2020