Deglacial Climate Change

Radiocarbon dates showing the retreat of the N. American ice sheet

Coral data provided data on the rate of sea level change

Proxy records provide evidence for a cold episode (Younger Dryas) that interrupted the deglacial process.

The Greenland ice cores show rapid (<100 yrs) changes in ice accumulation and dust.

Routes of meltwater flow

Deglaciation flooding of coastlines

Tropical monsoons were stronger in the northern hemisphere 9,000 yrs ago

Proxy records also show tropical monsoon maximum 9,000 yrs ago.

Decreased summer insolation in the northern tropics has produced weaker tropical monsoons.

Decreased summer insolation at high northern latitudes during the last 6,000 yrs coincides with cooler temperatures.

Humans and Paleoclimate

The spread of agriculture

Quelccaya ice cap in Peru

The Little Ice Age could have resulted from orbital-scale cooling or from a millennial-scale oscillation.