LONDON, Sept. 7 (UPI) -- Fossilized algae from beneath the Arctic Ocean sea bed shows the area was sub-tropical 55 million years ago, the BBC reported Tuesday.
Scientists from eight countries working with the Arctic Coring Expedition, or ACEX, said drilled core samples show the sea temperature was once about 68 degrees, instead of the average 29 degrees it is now.
The expedition relied on three icebreakers during its work, and was sailing heading back to Tromso in Norway, the BBC said.
The samples date back to a period known as the Paleocene-Eocene thermal maximum, a brief period that occurred around 55 million years ago. It was characterized by an extremely warm climate that created a natural greenhouse effect, which caused massive amounts of carbon to be deposited in both sea and air.
"We're seeing a mass extinction of sea-bottom-living organisms caused by these conditions," said Dr. Michael Kaminski, a paleontologist from University College London.
