Collapse

Easter's chiefs and priests had previously justified their elite status by claiming relationship to the gods, and by promising to deliver prosperity and bountiful harvests.  As their promises were being proved increasingly hollow, the power of the chiefs and priests was overthrown around 1680 by military leaders called matatoa, and Easter's formerly complexly integrated society collapsed in an epidemic of civil war...

...Oral traditions record that the last ahu [stone platforms] and moai [the famous Easter Island statues] were erected around 1620, and that Paro (the tallest statue) was among the last... That the sizes of the statues had been increasing may reflect not only rival chiefs vying to outdo each other, but also more urgent appeals to ancestors necessitated by the growing environmental crisis.

From Collapse, by Jared Diamond. With our own island's political elite apparently too paralysed by panic to do anything about a readily apparent crisis, other than fight among themselves and make obviously undeliverable promises, it seems to me that we've not learned as much from past catastrophes as we should have.