Scientists with the U.S. Geological Survey (USGS) and the University of Alaska, Fairbanks released a study claiming the “stratigraphic record of the last 1.5 [million years] indicates that no marine species’ extinction events occurred despite major climate oscillations,” including periods where the Arctic was completely ice-free in summertime.
“Some species thought to be dependent on summer sea ice (e.g., polar bears) survived through these periods,” write Thomas Cronin of the USGS and Matthew Cronin of the University of Alaska in their new study.
“In the case of summer sea-ice-free interglacial periods, the presence of winter sea ice habitat, polar bears’ ability to fast during summer, seals ability to use land areas in the absence of sea ice, and the availability of new prey species shifting ranges into the Arctic may have allowed survival during warm periods,” Cronin and Cronin write.
Read more: ‘No Extinctions’: Polar Bears Survived Periods When The Arctic Had No Ice