[jcranmer]

It should be noted that virtually every case that Diamond brings up are situations where climate change is not implicated as part of the decline. For example:

* The Viking Greenlanders: collapsed primarily due to the North Sea trade routes shifting away from visiting Greenland. Note that Diamond also implicates the reluctance of the Vikings to eat fish, which is mystifying, because fish was a big part of their diet, and today, Nordic cultures' all have a signature fermented fish dish.

* Easter Island: more contentious, but the environmental degradation appears to have largely happened after visitation from Europeans and the collapse of the Rapa Nui civilization, not before.

* Classic Mayan civilization: there's no firm consensus on what brings about the Classic Maya collapse. But it should be noted that from the Late Classic to Early Postclassic, the dominant Mayan centers shift from the ecologically more productive highlands to the more ecologically fragile lowlands (where it persists for several centuries in the Postclassic), which is a bit hard to square with environmental degradation theories.

[FrustratedMonky]

Maybe confusing 'Climate Change' with 'local environment'. Think all cases in the book deal with how humans impacted the 'local environment' and changed it to a degree that could not be sustained. Not that they caused a global change, or that a global change impacted them.

[TrainedMonkey]

> Note that Diamond also implicates the reluctance of the Vikings to eat fish, which is mystifying

Completely guessing, but maybe eating fish turned out to be a huge evolutionary advantage... so groups that did outcompeted groups that did not.

[AlotOfReading]

No, this is just one of the many cases where Diamond simply wasn't familiar with the basic facts of the situations he wrote about. He's notorious for it. Later studies have indicated that the last couple centuries of Norse Greenlanders ate a diet rich in fish and other marine animals.