Global warming 55 million years ago shifted ocean currents


Brietbart – January 4, 2007

This is a very good overview of a scientific paper that details how a historic global warming event dramatically changed the Earth’s ocean currents. The article does not lay significant claim as to what caused the warming, only its dramatic effects. The article does compare today’s level of carbon dioxide and theorizes a similar catastrophe.

The big event, the Palaeocene/Eocene Thermal Maximum (PETM), saw the planet’s surface temperature rise by between five and eight degrees C (nine and 16.2 F) in a very short time, unleashing climate shifts that endured tens of thousands of years.

With a painstaking reconstruction, Nunes and Norris found that the world’s ocean current system did a U-turn during the PETM — and then, ultimately, reversed itself.

The huge temperature rise may have occurred within just few thousand years, but as Nunes and Norris point out, the effects were enduring and the lesson for mankind today is clear.The suspected reason for this is an inrush of freshwater into the northern Atlantic, caused by melting glaciers in Greenland and melting sea ice, and higher flow into the Arctic from Siberian rivers caused by greater rainfall. The influx brakes the conveyor belt in which warm surface water is taken up to the northeastern Atlantic from the tropics before returning down to the southern hemisphere as cool, deep-sea water.

Read the entire article here.

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