The Arctic has been warming for longer than previously thought, a new study suggests

A new study of marine sediments in Fram Strait found evidence of changes beginning in the early 1900s.

Parts of the Arctic Ocean have been warming since decades earlier than previous observations would suggest, according to a new study in the journal Science Advances that used marine debris to reconstruct 800 years of data.

The study found that the Arctic water’s temperature and salinity in the Fram Strait — between Svalbard and Greenland — remained relatively constant until the early 1900s, but at that point heat and salt transported from the Atlantic Ocean began to increase substantially, possibly linked with the period in which humans had begun ‘supercharging’ the atmosphere with carbon dioxide, and thus possibly suggesting the Arctic is more sensitive to greenhouse gases than previously thought, according to study co-author Francesco Muschitiello, who spoke to CNN.

[The Arctic Ocean is becoming more like the Atlantic and Pacific, studies say]

The study is clear that the causes of this early ‘Atlantification’ are not yet fully understood, but it does suggest changes in the Atlantic Meridional Overturning Circulation — currents that moderate temperatures in the Northern Hemisphere — could have played a role and, regardless of the specific mechanisms behind it, CNN notes that once rapid warming in the Arctic causes ice to melt a feedback loop begins, whereby the lack of ice causes even warmer temperatures, because without the bright white sea ice to reflect away the sun’s energy, the dark ocean absorbs it as heat.

Detailing how things stand now, Muschitiello added: ‘the Arctic is warming very, very quickly, and much faster than any other area on the planet.’”