The Lost Civilisation of Peru: Impossible Storms?

Is it possible that extreme weather conditions were responsible for the downfall of a whole civilisation? Archaeologists discuss the possibility in this clip from 'The Lost Civilisation of Peru'.
3
The Lost Civilisation of Peru: Discovering Skeletons
The Lost Civilisation of Peru: Shattering Theories
The Lost Civilisation of Peru: Taming the Desert
The Lost Civilisation of Peru: Civil War
The Lost Civilisation of Peru: Decades of Drought
Mystery of Easter Island: Polynesian Link
Mystery of Easter Island: Discovering Easter Island
Mystery of Easter Island: Disaster Theory
Mystery of Easter Island: First Breakthrough
Mystery of Easter Island: Spear Tips & Civil War