By looking at the more distant past sea ice and then what’s happened after the huge glug of carbon pollution humans have dumped in the atmosphere, the results suggest that it’s possible today’s sea ice is coming into equilibrium with carbon dioxide levels from 100 years ago. “The alarming potential conclusion from this is that sea ice in 2018 is responding to warming conditions from previous decades,” Jones said. “And so if we just extrapolate that relationship, we essentially already locked in a complete loss of winter sea ice in the Bering Sea.
Using that information, she reconstructed 5,500 years of climate over the region and found nothing that stacked up to 2018's bizarre behavior. “The loss of winter sea ice is pretty alarming, because you expect the ice to be there in the wintertime and be there pretty reliably,” she said. “That’s what’s so shocking for 2018, and it created a lot of problems for Indigenous communities that live along the Bering Sea and rely on that sea ice to fish.