Easter Island, C'est Moi

In his Pulitzer-prize winning book, "Guns, Germs, and Steel," Jared Diamond examined how and why Western civilizations developed the technologies and immunities that allowed them to dominate much of the world. Now in "Collapse: How Societies Choose To Fail Or Succeed," Diamond probes the other side of the equation: What caused some of the great civilizations of the past to collapse into ruin, and what can we learn from their fates? From the Polynesian cultures on Easter Island to the flourishing American civilizations of the Anasazi and the Maya, and finally to the doomed Viking colony on Greenland, "Collapse" traces the fundamental patterns of catastrophe.

TERRENCE MCNALLY: What called to you about the new book, "Collapse"?

JARED DIAMOND: What called to me was a romantic interest going back to when I was in my 20s and began reading Thor Heyerdahl's books about the settlement of Easter Island and the great stone statues and how they were erected and why they were overthrown. It's a question that's been on my mind for a long time.

Twenty years ago we really didn't know why the islanders ended up in this barren landscape overthrowing their statues. It also wasn't clear why the Maya had abandoned their great cities. But thanks to recent archeological excavations we now have better understanding of these collapses. It's now possible to write a unified book on collapses.

You put forth a five-point framework of factors that tend to contribute to collapse. Could you tell us what they are, in terms of one of the actual cases in the book?

Let's take a full five-factor collapse that involves a European society (collapses happen not just to exotic people like Polynesians or Native Americans, they happen to blue-eyed, blonde-haired Europeans like Norwegians). The Vikings settled Greenland around C.E. 1000. They built cathedrals and stone churches. They were literate, they wrote Latin and they wrote in runes. But after about 500 years they were all dead. Still, the Norse lasted longer in Greenland than Europeans have lasted in North America today.

Number one: human environmental impacts. Many societies unwittingly destroy the environmental resources on which they depend. The Greenland Norse chopped down their forests in order to clear land for pastures and to have firewood and construction timber, but that resulted in erosion that gradually removed land that could have been used for productive pastures.

Number two: climate change. Today we're causing climate change, but in the past the climate has naturally gotten colder or hotter or rainy or drier. In the case of the Greenland Norse, it got colder. If it's colder, you grow less hay to get your cattle through the winter and your cattle start dying.

The third factor was enemies. Most societies have enemies, and can fight off their enemies until the society gets weakened for whatever reason. The Roman Empire weakened and then was overrun by barbarians. In the case of the Greenland Norse, as they weakened, their enemies, the Inuit or Eskimos, probably played a role in exterminating them.

Factor number four: friends. The Greenland Norse depended upon Norway for essential resources, particularly iron and timber, and for cultural identity. Norway began to decline, and the trade from Norway to Greenland was impeded by sea ice.

And number five: every society responds or fails to respond to its problems. The Greenland Norse failed to respond successfully.

I find their failure very instructive. What happened?

It's a very interesting question, why a society doesn't even notice or doesn't successfully respond to problems that look obvious. You would think, not a good idea to chop down all the trees and cause soil erosion. They needed timber and pastures, how could they be so dumb?