Archaeology Magazine Archive

A publication of the Archaeological Institute of America

Special Introductory Offer!

Beyond Stone & Bone

An Inconvenient Truth in 5000 B.C.
by Heather Pringle
August 21, 2009

Slashing-and-burningWhen did human beings first begin leaving their heavy, mucky, ruinous footprints on the environment?  When did our ancestors start overhunting great herds of bison and other large game, fishing ocean stocks to exhaustion and boosting global levels of greenhouse gases in the atmosphere?   Most environmentalists tend to pin the blame entirely on recent generations —laying the responsibility at the feet of those who lived from the industrial revolution to the present day.

But popular as this view is, it is short-sighted and plainly wrong-headed.   I first began to twig to this fact in the 1990s when I was researching a book chapter on Head-Smashed-In Buffalo Jump in Southern Alberta.  As I strolled the windblown site with Royal Museum of Alberta archaeologist Jack Brink—who excavated the jump’s massive bone bed over a nine-year period— he took me completely by surprise.   The first people to drive herds over the jump, some 5700 years ago, he explained, slaughtered far more animals than they needed.  “These people weren’t concerned with storage of food or with getting all the nutritional value out of a carcass that they possibly could,” Brink said.   “It was more like, ‘Let’s get a big meat meal.  Let’s stuff ourselves and get out of here.”

Indeed, nearly 4000 years passed at Head-Smashed-In before hunters began diligently reversing this trend.   Around 2000 years ago, they began boiling bison bones from their kills to extract grease:   this they mixed with bison meat and berries to make pemmican, which they then stored in sewn rawhide bags.  It was a clever way of preserving meat:  some historical accounts suggest that pemmican could be successfully stored in these airtight bags for 20 years.  In other words, later bison hunters of Southern Alberta were far less wasteful and profligate than their predecessors:  they extracted all the calories possible from their kills.

Now a new article in Quaternary Science Reviews serves up yet another fascinating example of how early, preindustrial peoples impacted their environment—this time by looking at greenhouse gases.   Two climate scientists, William Ruddiman at the University of Virginia in Charlottesville and Erle Ellis at the University of Maryland in Baltimore County, did this by examining both archaeological data on forest clearance by early agriculturalists and environmental data on carbon dioxide levels in the atmosphere over time.

Early farmers, who practiced slash-and-burn agriculture, cleared vast tracts of land in order to support a family.  One square kilometer fed less than 15 people.  But as populations rose over time, cultures greatly improved on this.  They developed sophisticated canal and irrigation systems, fertilized crops with manure from livestock,  controlled insects,  and planted two or more crops a year.  With  intensive agricultural practices,   one square kilometer could feed more than 250 people.

What this all means is that early farmers were clearing forests like crazy—indeed to a far greater extent than climate scientists had previously recognized.  Intrigued by this, Ruddiman and Ellis began looking at the trajectory of greenhouse gases in the atmosphere beginning some 7000 years ago.  Their new findings strongly suggest that farmers were releasing major amounts of carbon into the atmosphere as early as 7000 years ago by cutting down vast tracts of trees.  And all this added significantly to our planet’s levels of greenhouse gases.

I think this is an important study for several reasons.  It shows us, says Ruddiman, that early farmers “had surprisingly large effects [on the environment] despite their low numbers.”   And it also clearly reveals the great relevance of data from the ancient past to understanding one of the most pressing matters on the political agenda today – climate change.   For archaeologists, whose work is regarded by some as musty and irrelevant, this is a very welcome development.

Comments posted here do not represent the views or policies of the Archaeological Institute of America.

7 comments for "An Inconvenient Truth in 5000 B.C."

  • Reply posted by Johan Normark (August 23, 2009, 9:20 pm):

    One can also see these developments as being politically correct interpretations. Studies like these are getting funds due to the awareness of the contemporary climate problems. Archaeological studies tend to follow the ups and downs of what media reports. Studies on ancient Maya warfare increased during the Vietnam war, etc. From my personal experience I can see that my current research on cave use in northern Yucatan only got funding from one minor fund when I tried to make a cognitive study of the caves. Once I changed the study to a climatological one I received money from ten other funds… (and the cognitive study would have been more interesting).

    In any case, both “natural” and anthropogenic causes for climate change as explanation for the “Maya collapse” are popular nowadays. Climate change was important but many of these models are actually based on how climate affects present or Colonial period communities. However, if one compares the Colonial and the pre-Columbian settlement patterns they differ greatly. So, my main argument is that the whole “climate cause scenario” for the “Maya collapse” mainly is based on communities created and affected by later sociopolitical and religious changes (Spanish conquest, congregation, Catholicism, etc).

    Basically, what I am trying to say is that I do believe archaeology can point out how people have dealt with their self-inflicted or “natural” climate changes in the past. But I do not believe these studies are relevant for our current climate problems since there usually are complex sociopolitical, economical and religious causes as well and these are much harder to detect in social formations 7,000 years old.


  • Reply posted by Kathryn Hadley (August 24, 2009, 12:38 am):

    This is a really interesting post.
    It is true that with the current topicality of issues of climate change, there have been considerable developments in the study of environmental history.
    Although it focuses on a much more recent history, the British Academy is organising a conference on the changing landscape of east-central Europe c1700-1989 at the University of Oxford from September 24th-26th.


  • Reply posted by Dan Hilborn (August 25, 2009, 8:46 am):

    Another example?

    Weir building may have had a greater impact on the North American landscape than is commonly accepted. I’ve met several first nations historians who claim that whole lakes and river deltas could have been altered and/or created over a period of centuries by the meticulous work of their ancestors.

    Of course, our modern ability to find evidence of such activity is limited. Wooden pilings, woven baskets, and utensils made of bark leave little trace of themselves in a wet coastal environment.


  • Reply posted by Maria Eliferova, PhD (September 3, 2009, 1:58 am):

    Somebody HAS to say it.
    Well, where have UK’s forests gone? England had been deforestated well before the industrial revolution. Surely, if people in this and that and that another country cut down trees and do not plant any, it MUST affect climate finally.
    The Moscow archaeologists found that the concentration of lead and other such stuff in the 15th to 16th century layers was enormous! People were not aware that these metals were poisonous, they used lead and mercury for paints, medicines and even make-up. Wouldn’t all this go into soil and water? And should we be amazed by the fact that sturgeons are long gone from the Moscow River?
    It is time to stop these New Age myths of our eco-friendly ancestors living ‘in harmony with Nature’.


  • Reply posted by Peter Clack (September 14, 2009, 7:27 pm):

    The hills in NE England were deforested during the Bronze Age c 3,000 years ago, thereby affecting drainage patgterns. The area is now covered in blanket bog.


  • Reply posted by Geoff Carter (November 11, 2009, 5:48 am):

    The continuity of settlement in the early Neolithic (LBK) argues against widespread slash and burn. In addition the need for timber for building and other technologies required the development of managed woodland.

    The biggest impact on woodland cover would result from smelting of metal ores. For charcoal smelting of copper 300 tonnes of charcoal would produce 1 tonne of copper. 300 tonnes of charcoal would require 3000 – 6000 tonnes of wood.


  • Reply posted by Gavin Lyall (March 16, 2011, 5:10 pm):

    How about 11,000 BCE?
    Pre-(and post-)agricultural cultures worldwide have commonly set large-scale fires to flush out game and encourage edible plant growth. I have long suspected that such practices may have played a part in ending the last ice age. I’m happy to see “early Anthropocene” theories finally getting publicity–I’ve only met with scoffs for mine. Well, now I’ll show them all!
    Mwahahahah! Cough, ahem.
    Maybe it’s for the best that I tripped on this thread so late…


About Our Blogger:

Heather Pringle is a freelance science journalist who has been writing about archaeology for more than 20 years. She is the author of Master Plan: Himmler's Scholars and the Holocaust and The Mummy Congress: Science, Obsession, and the Everlasting Dead. For more about Heather, see our interview or visit

Thanks for writing! While we may not be able to respond to every message, we appreciate your comments and suggestions. (Comments are now closed.)

RSS feed
Trowel Tales: The AIA Blog