Details

Autor(en) / Beteiligte

• Dull, Robert A.
• Nevle, Richard J.
• Woods, William I.
• Bird, Dennis K.
• Avnery, Shiri
• Denevan, William M.

Titel

The Columbian Encounter and the Little Ice Age: Abrupt Land Use Change, Fire, and Greenhouse Forcing

Ist Teil von

• Annals of the Association of American Geographers, 2010-10, Vol.100 (4), p.755-771

Ort / Verlag

Washington: Taylor & Francis Group

Erscheinungsjahr

2010

Link zum Volltext

Quelle

Taylor & Francis

Beschreibungen/Notizen

• Pre-Columbian farmers of the Neotropical lowlands numbered an estimated 25 million by 1492, with at least 80 percent living within forest biomes. It is now well established that significant areas of Neotropical forests were cleared and burned to facilitate agricultural activities before the arrival of Europeans. Paleoecological and archaeological evidence shows that demographic pressure on forest resources-facilitated by anthropogenic burning-increased steadily throughout the Late Holocene, peaking when Europeans arrived in the late fifteenth century. The introduction of Old World diseases led to recurrent epidemics and resulted in an unprecedented population crash throughout the Neotropics. The rapid demographic collapse was mostly complete by 1650, by which time it is estimated that about 95 percent of all indigenous inhabitants of the region had perished. We review fire history records from throughout the Neotropical lowlands and report new high-resolution charcoal records and demographic estimates that together support the idea that the Neotropical lowlands went from being a net source of CO 2 to the atmosphere before Columbus to a net carbon sink for several centuries following the Columbian encounter. We argue that the regrowth of Neotropical forests following the Columbian encounter led to terrestrial biospheric carbon sequestration on the order of 2 to 5 Pg C, thereby contributing to the well-documented decrease in atmospheric CO 2 recorded in Antarctic ice cores from about 1500 through 1750, a trend previously attributed exclusively to decreases in solar irradiance and an increase in global volcanic activity. We conclude that the post-Columbian carbon sequestration event was a significant forcing mechanism of Little Ice Age cooling.