Climate Change - The Pliocene Rebooted

Atmospheric carbon dioxide concentration is now around 400 parts per million (ppm).
It last reached similar levels during the Pliocene, 5.3-2.6 million years ago.


During this period, the area around the North Pole was much warmer and wetter than it is now.


 Summer temperatures in the Arctic were around 15 degrees C, which is about 8 degrees C warmer than they are now.

 Global average temperatures were 2-3°C warmer than today.
Sea level rose by up to 20 metres.

Of course, there were no modern humans at that time.

Nor was there a global system of food supply relying on stable climates for agriculture.

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