American History – June 2019

6 AMERICAN HISTORY

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Before the Deluge

Indian village in what

is now Florida included

cultivated lands.

by Sarah Richardson

The "Great Dying"—the deaths 1500-1600 of more

than 55 million New World natives—led to the Little

Ice Age, an anomalous drop in global temperature 1570

to 1694 known as the Little Ice Age. That is the conclu-

sion of scientists from the University College London

and the University of Leeds. During roughly the same

era, the researchers write in the March 2019 Quater-

nary Science Reviews, less carbon dioxide concentrated

in the air. This coincided with the only period in the

past 2,000 years that saw the global temperature drop.

Reviewing population estimates, land use studies, and

atmospheric carbon dioxide recorded in Antarctic ice

cores, the team mapped an extensive depopulation in the New World caused by diseases from Europe such as smallpox,

measles, influenza, yellow, malaria, diphtheria, and typhus. The first documented epidemic in Mexico occurred in 1517.

Others followed, often in waves reaching into the interior. The worst die-offs were in Mexico. Within a century, the

authors estimate, 95 percent of the New World's populace had died. The combined impact far surpassed those of individ-

ual pathogens, such as the bubonic plague that caused the Black Death in Europe in the 14th century. Warfare and slavery,

the report notes, compounded the deaths. The die-off left untended what had been extensively cultivated lands, ranging

from fields terraced by the Inca to croplands in Central and North America to forest gardens in the Amazon. Forests and

grassland vigorously reclaimed an estimated one percent of the total landmass of the Americas. This vegetative comeback

took up atmospheric carbon dioxide, a climate-warming gas, helping to explain the mysterious dip in global temperature.

The historical significance lies in a reset of the Anthropocene, referring to the age in which humans began making

observable impacts on the global atmosphere and environment.

According to the authors: “These changes show that human actions had global impacts on the Earth system in the cen-

turies prior to the Industrial Revolution. Our results also show that this aspect of the Columbian Exchange—the globaliza-

tion of diseases—had global impacts on the Earth system, key evidence in the calls for the drop in atmospheric CO2 at

1610 CE [Christian Era] to mark the onset of the Anthropocene epoch.”

Little Ice Age

Linked to

Die-Off in the

Americas