In this book he writes about a number of societies that encounter a host of problems - some of which result in failure. I was drawn to it because of his analysis of Easter Island. Thus far I've read about Montana (not failed), Easter Island, Pitcairn and Henderson Islands, the Anasazi, and the Mayans - more failures to come as well as a lot of political-econmic analysis.
He takes a very scientific approach using information from many other scientists and includes his own analysis as well. He clearly expresses his opinion but allows for the situation that there are many opinions and some contradictory data so he might be wrong. He does an excellent job explaining the science involved. An example of this is where he discusses Dendrochronology by which a climate whose rainfall varies a lot over large time spans (not true for all areas) allows scientists to make a pretty valid estimate as to when a tree used in a structure was cut down as a means to date a structure.
I loved this sequence of sentences near the beginning.
"So that readers will have some advance idea where they are heading, here is how this book is organized. Its plan resembles a boa constrictor that has swallowed two very large sheep."
He talks about five factors:
• damage that people inadvertently inflict on their environment,
• climate change,
• hostile neighbors,
• decreased support by friendly neighbors,
• how the society responds to problems.
He uses this framework to discuss each place that he analyzes.
In the Montana chapter he talks about the effects of mining, deforestation, lack of rainfall and distance from markets that set the stage for a large set of problems. On the other hand the fact that it is so beautiful there has attracted a large number of wealthy people to buy land and built fancy homes (but not be residents who pay state taxes). This causes land prices to go way up so farming becomes difficult - note that here is where the estate tax comes in because when the children inherit a family farm that barely has enough income to keep alive they suddenly have to pay a large tax and have to sell the farmland for development. This community is still healthy primarily because of financial support from outside - government and the out-of-state land owners who also get houses built and use services. But the potential conflict between old-timers vs new-comers could destabilize the place. (Full disclosure: This is an overly simplistic description of his analysis.)
For Easter Island his analysis is that its collapse was due basically because the people overexploited its own resources. At the time there were no friendly neighbors or enemies and it looks like the climate didn't change so he believes those factors can be ruled out. Essentially deforestation made fishing impossible because they couldn't build canoes, the population was too large for local farming on bad soil (deforestation made it worse) to get enough food and as a result there was so much strife between the rival tribes. Essentially a massive civil war resulted in the killing of most of the people. Of course a bit later there was the hostile neighbors problem where the Peruvians kidnapped about 1/2 the population to be slave labor and later when some returned they brought smallpox.
Of course you can see the parallel to some of our near future dilemma. We are messing up our environment, the climate is changing and may well be more hostile, each country has friendly neighbors and hostile enemies. Currently we are not responding well to many of these problems. The earth is not going to be saved by friendly neighbors from nearby planets and not many people can migrate to them. So we are going to have to figure out what to do, or...