Philippe Matthews Show Guru Advice, Author Reviews, Tech Reviews, Entertainment News

Historians have speculated for years that global environmental changes caused some ancient wars to erupt, or even societies to collapse. Such connections may still exist--because new research finds that the risk of civil war in tropical countries increases during hot, dry El Nino years as opposed to cooler La Nina periods.

Historians have speculated for years that global environmental changes caused some ancient wars to erupt, or even societies to collapse. Such connections may still exist--because new research finds that the risk of civil war in tropical countries increases during hot, dry El Nino years as opposed to cooler La Nina periods. The study is in the journal Nature .