|A.Eisenstaedt, Oklahoma Farmer 1942, Time & Life Pictures/Getty Images|
After the passing of the plagues, and the brutal conquest that ensued, those Native Americans who remained were reduced to a state of extreme poverty. Before European contact, the people of Amazonia cultivated or managed at least 138 of the 257 plant species cultivated in the Western Hemisphere. Two centuries later, they were reduced to farming only a handful.Anthropologist Charles C. Mann says, “The pall of sorrow that engulfed the hemisphere was immeasurable. Languages, prayers, hopes, habits, and dreams — entire ways of life — hissed away like steam.”When the civilizations of the Americas perished, with them perished the agricultural sciences gained from millennia of field trials. Countless valuable domestic cultivars, unable to self-propagate, went extinct. Where great shining cities had stood, vines and moss covered the façades; trees broke through the paving stones and engulfed buildings. Rain rotted away the roof timbers, and insects ate the parchment of scientific and literary manuscripts, leaving but a few to the bonfires of the conquerors.So great was the burst of vegetation over open fields and mounded cities in the Western Hemisphere that the carbon drawn from the air to feed this greening upset atmospheric chemistry. Analysis of the soils and lake sediments at the sites of both pre-contact population centers and sparsely populated surrounding regions reveals that the reforestation of land following the collapse drew so much carbon out of the atmosphere so rapidly that Europe literally froze.That period of global cooling, which was most intense from approximately 1500 to 1750, is known as the Little Ice Age. The Little Ice Age ended the Medieval Warming Period that corresponded to the time when the Amazon was not jungle, but tall white cities with many miles of wharf-front, wide causeways extending inland, and highly cultivated societies.