Geoscience Reference
In-Depth Information
ten
h
e Little Ice Age
megafloods and climate swings
h e lessons of the Little Ice Age are twofold. First, climate
change does not come in gentle, easy stages. It comes in sud-
den shit s from one regime to another—shit s whose causes are
unknown to us and whose direction is beyond our control. Sec-
ond, climate will have its sway in human events. Its inl uence
may be profound, occasionally even decisive. h e Little Ice Age is
a chronicle of human vulnerability in the face of sudden climate
change. In our own ways, despite our air-conditioned cars and
computer-controlled irrigation systems, we are no less vulnerable
today. h ere is no doubt that we will adapt again, or that the
price, as always, will be high.
Brian Fagan,
h
e Little Ice Age
san francisco bay
The deep droughts of the Medieval Climate Anomaly eventually
drew to a close around AD 1400. For much of the 150 years prior to this date,
extreme l ooding was relatively rare. In California, people who lived in the
broad Central Valley and around the San Francisco Bay would have seen irreg-
ular rainfall for hundreds of years, with the winters ot en failing to deliver
the big storms that i lled the lakes and fed the mountain snowpack. Around
the bay, the mounded villages were empty most years; since the drought had
begun, the creeks l owing to the marshlands dried early in the summer, forcing
the people to make long treks for freshwater or, if their camps were inland near
the larger creeks, long foraging expeditions to the mudl ats in the bay to col-
lect mussels and other shelli sh. h e native populations throughout the region
suf ered, some perished, and some managed to adapt to the dry conditions.
h e pattern of weather began to change, however, and those who paid
attention would have noticed the series of cold storms that now began the
