Stalagmite reveals carbon footprint of early Native Americans

[n2doc]

Published: Thursday, April 15, 2010 - 11:32 in Paleontology & Archaeology

A new study led by Ohio University scientists suggests that early Native Americans left a bigger carbon footprint than previously thought, providing more evidence that humans impacted global climate long before the modern industrial era. Chemical analysis of a stalagmite found in the mountainous Buckeye Creek basin of West Virginia suggests that native people contributed a significant level of greenhouse gases to the atmosphere through land use practices. The early Native Americans burned trees to actively manage the forests to yield the nuts and fruit that were a large part of their diets.

"They had achieved a pretty sophisticated level of living that I don't think people have fully appreciated," said Gregory Springer, an associate professor of geological sciences at Ohio University and lead author of the study, which was published a recent issue of the journal The Holocene. "They were very advanced, and they knew how to get the most out of the forests and landscapes they lived in. This was all across North America, not just a few locations."

Initially, Springer and research collaborators from University of Texas at Arlington and University of Minnesota were studying historic drought cycles in North America using carbon isotopes in stalagmites. To their surprise, the carbon record contained evidence of a major change in the local ecosystem beginning at 100 B.C. This intrigued the team because an archeological excavation in a nearby cave had yielded evidence of a Native American community there 2,000 years ago.

Springer recruited two Ohio University graduate students to examine stream sediments, and with the help of Harold Rowe of University of Texas at Arlington, the team found very high levels of charcoal beginning 2,000 years ago, as well as a carbon isotope history similar to the stalagmite.

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http://esciencenews.com/articles/2010/04/15/stalagmite.reveals.carbon.footprint.early.native.americans

[xchrom]

1. An extraordinary find. Nt

[dhpgetsit]

2. It's not the same Our damage to the atmosphere is much more long-term.

Yes they did burn forests to create clearings and grasslands for game to thrive in. And the burned grasslands to drive game animals into ambush points.

But the fuel they burned was on the earth's surface. It was practically atmospheric carbon already. Last year's sunlight. What we have been doing is burning fossil fuels as fast as we can extract it from deep underground where it has been locked away for millions of years. And there is no real chance that all that carbon can be absorbed back into the trees and plants. Our damage to the atmosphere is much more long-term.

[Igel]

5. True, but not overly important a point.

The forests had sequestered many tons of carbon for a long time--releasing it when an ice-age killed off the forests and the detritus rotted, absorbing it as the glaciers retreated and the earth warmed. A nice cycle, that.

Then, starting sometime before 12k years ago when the "indigenous" populations of the Americans arrived that carbon started to be released into the atmosphere. Apparently, at least in the mid-West, this wasn't all that extensive until shortly BCE.

But there's a more important point, and it's not AGW related: It's the way the oldest American immigrant populations interacted with nature. Many people romanticize pre-Columbian land use and imagine that the peoples here were one with the land, that they didn't control it or shape it to the extent their technologies allowed. There's this green "wilderness" ethos, where "white man" found wilderness to tame. So when it turns out that a couple thousand years ago natives in S. California overfished some shellfish and drove them to extinction, it's usually met with shock and denial. Same for this kind of thing.

White man did encounter wilderness, but mostly because the Spanish explorers seeded some very nasty diseases in their journeys, diseases which spread and reduced the population in the 100 years before anybody but the Iberians were setting up shop in North America.

This says something interesting about the scope and time depth of dendriculture by the locals.

Similar work was done perhaps 5 years ago to document the spread in Europe of the domestication of animals (and grazing) and then agriculture a few thousand years later. As forests were cleared or prevented from growing and more territory turned over to grazing or agriculture a lot of CO2 was put into the air. (Not counting the methane from the animals.)

[denbot]

3. Here in California (Yosemite) the Shoshone and Yokuts burned Meadows.

This kept saplings from converting crop areas back to forest.

[YankeyMCC]

4. The "wilderness" the pilgrims found

was only abandoned areas , this management worked for many thousands of years and that's the difference. Certainly they had an impact, we are part of the ecology we have to have an impact. The difference as the people here had learned to live in a way that their impact fit much more sustainably than what we do now. They recognized the connection, for the most part people in the western world at least don't, at least that's what it seems like to me.