Paul Beckwith – Feb 28, 2021
A ground-breaking new finding in climate recently just occurred, and it seems blindingly obvious, in retrospect. In fact I became very close to figuring this out all by myself, many years ago.
During extremely cold, long duration ice ages, at two different periods in the last 150,000 years; namely (a) 60,000 to 70,000 years ago, and (b) 130,000 to 150,000 years ago; the entire Arctic Ocean was fresh liquid water, entombed underneath a thick ice layer, and separated from the Pacific Ocean by land, and from the Atlantic Ocean by a combination of land and grounded ice shelves, with only small passages where fresh water would exit, keeping salt water from entering. How was this possible?
During these exceptionally cold, long duration cold periods there was so much water stored within the glacial ice that global sea levels were lower by 130 meters (430 ft). With sea levels this low, the Bering Strait sea floor became dry land, as well as all the gaps within the Canadian Archipelago and the Nares Strait. There was no water channel connection to the Pacific Ocean at all.
On the Atlantic Ocean side of the Arctic, the ocean passages become greatly reduced by the lower sea level exposing the continental shelves. Very thick ice sheets on Greenland and Europe created extensive ice shelves on the coastlines that extended far out into the Arctic Ocean, and these ice shelves, up to 900 meters thick (90 meters above sea level, 810 meters below sea level) almost completely blocked off the remaining ocean passages between the Arctic Ocean and the Atlantic Ocean, between Greenland and northern Scotland.
Lots of fresh water still entered the Arctic Ocean, from meltwater, northern rivers, rainfall, and snow melt. Therefore, over time freshwater built up in the Arctic Ocean basin, floating above and eventually forcing out the remaining salt water near the ocean floor. Clearly, this led to an entirely fresh Arctic Ocean.
When these ice ages ended due to Milankovitch Cycle changes in Earth’s orbit around the Sun, and the Earth started warming, the sea level rose again and the ice shelves thinned, releasing huge amounts of fresh water back into the Atlantic Ocean and then the Pacific, causing enormous wrenching temperature swings and abrupt climate oscillations until the climate system again reached stability. The Arctic Ocean once again became a salty ocean.
One of my subsequent videos goes through the peer reviewed paper on this with a fine toothed comb…