Charles L. Redman

Human Impact on Ancient Environments has a lot of interesting information, but doesn’t go much of anywhere with it. Author Charles Redman is a Professor of Sustainability at the University of Arizona. It’s hard to figure out who his expected audience is – at the start the book seems to be a very basic ecology text, with inputs and output diagrams and explanations of primary producers and primary and secondary consumers, so you might expect it to continue to be addressed to a curious lay audience. Then, however, it transitions to a scholarly analysis of ancient Levantine and Southwest American societies and their effects on their environments, and tries to fit that into a generalized quasiMalthusian argument that food production will always eventually cause environmental degeneration. That leads you to expect a Paul Ehrlich style “We’re all doomed” conclusion, but Dr. Redman switches horses yet again and his conclusion – as near as the book has a conclusion – is that human creativity and ingenuity will overcome environmental problems.


Of particular note is Redman’s point that there are no “pristine” environments undisturbed by human activities, and that there is no agreement on what constitutes a “natural” environment. He discusses the common fallacy that Native Americans (all New World inhabitants come under that designation) were somehow in ecological equilibrium with their society and that the land they inhabited was pristine and untouched until 1492 when it all went to Hades in a handbasket. This requires some explanation; as far as natives were concerned, European contact and the introduction of European disease were an unequivocal disaster; depending on who’s doing the estimating the population of the New World dropped by 75-90% between 1492 and 1750, including European arrivals. That, in turn, meant when English colonists began showing up on the North American east coast in the 17th century (and formulated what eventually became the typical American’s idea of what an “untouched” landscape was supposed to look like), they found an environment that was dramatically different from what it had been 100 or so years earlier when the conquistadors first showed up further south. The natives did extensive farming using slash-and-burn methods; fire was a particularly important factor, with the forests and the Great Plains ignited every year to improve game habitat even when land wasn’t being cleared for farming. Redman notes that one of his favorite sites, Yosemite Valley, was mostly grassland and scrub oak when the Ahwahnechee Indians lived there; the ponderosa pines that dominate now didn’t come until after the natives stopped setting fires. Similarly, the pre-Columbian bison population on the Great Plains was smaller than it was when the in the early part of the 19th century; the decimation of the native population by disease led to an increase in bison population (I’ve read independent confirmation of this in a book about Colorado archaeology; bison are completely missing from a good part of the Paleoindian archaeological record).


Redman is pretty good about referring to alternative views, but more recent work has called some of his conclusions into question. When the book was published, the conventional wisdom on one of his study areas – the Hohokam of southern Arizona – was that population pressure had destroyed their environment. Redman refers to the “collapse” of the Hohokam canal irrigation system, with the inference that this was due to overpopulation, the recently reviewed Archaeology of Environmental Change presents an alternative hypothesis – the Hohokam society changed such that large and elaborate canal systems were replaced by smaller, more rational ones. A similar, repeated theme of Redman’s is soil degradation due to overpopulation, among the evidence for this is apparent increases in sedimentation in the archaeological record. Again Archaeology of Environmental Change presents an alternative; erosion increases when population declines, not the other way around; it takes quite a bit of labor to maintain check dams, terraces, and other erosion-control features.

The publishers obviously attempted to draw on the popularity of Jared Diamond’s Collapse, since Human Impact on Ancient Environments has a superficially similar theme. There’s a short quote from Diamond on the cover of my paperback edition; a longer quote on the back cover; and an illustration of Easter Island moai on the front (a black and white negative image, presumably presented that way to make it look more ominous). When I thought about it, the moai puzzled me a little – since I didn’t remember any extensive discussion of Easter Island in the text. Checking the index, I found an entry for Easter Island alright, with several references – sometimes to multiple contiguous pages (i.e., “Easter Island, ecological economics, 32-33”). But when I checked those pages to see how I had missed these references, there was no mention of Easter Island. I can only assume they appeared in an earlier version and were removed without updating the index.


Lots of illustrations; however many are very generalized and don’t aid much in understanding. The bibliography seems too long for a popular work and too short for a scholarly one, and includes some rather strange choices (Kon-Tiki, Chariots of the Gods, and the Pergamon World Atlas, as originally published by the Polish Army Topographical Service). My general opinion is mixed; Redman’s discussion of pre-contact Native American environments is useful as an antidote to “ecological Indian” fallacies but the book as a whole just seems to lack focus and purpose.… (plus d'informations)