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4th millennium BC

(Redirected from 4000 BC)

(5th millennium BC4th millennium BC3rd millennium BC - other millennia)



3200 BC climate change

Based on studies by glaciologist Lonnie Thompson (professor at Ohio State University and researcher with the Byrd Polar Research Center) [1] a number of indicators shows there were a global change in climate 5,200 years ago:

  • The climate was altered suddenly with severe impacts.
  • Plants buried in the Quelccaya ice cap in the Peruvian Andes demonstrate the climate had shifted suddenly and severely to capture the plants and preserve them until now.
  • A man trapped in an Alpine glacier became trapped and died.
  • Tree rings from Ireland and England show this was their driest period.
  • Ice core records showing the ratio of two oxygen isotopes retrieved from the ice fields atop Africa’s Mount Kilimanjaro, a proxy for atmospheric temperature at the time snow fell.
  • The shift by the Sahara Desert from a habitable region to a barren desert.
  • Major changes in plant pollen uncovered from lakebed cores in South America.
  • Record lowest levels of methane retrieved from ice cores from Greenland and Antarctica.

Significant persons

Inventions, discoveries, introductions


External references

  • 3200 BC Climate Change

Last updated: 02-04-2005 18:22:22
Last updated: 03-09-2005 21:44:35