How has weather patterns such as the El Nino Southern Oscillation, the Peru Current, or the Trade Winds affected life and human activities in South America?

How has weather patterns such as the El Nino Southern Oscillation, the Peru Current, or the Trade Winds affected life and human activities in South America? 

Printed papers should be double spaced. Proper grammar and spelling are expected. Each paper should be 5 pages long and cover all aspects of the topic. Footnotes are not necessary but there should be a list of sources