... News . ... New study may answer long-standing questions about enigmatic Little Ice Age . A new study suggests that the onset of the Little Ice Age was caused by an unusual 50-year-long episode of four massive tropical volcanic eruptions. ... A new University of Colorado (CU) Boulder-led study appears to answer contentious questions about the onset and cause of Earthт??s Little Ice Age, a period of cooling temperatures that began after the Middle Ages and lasted into the late 19th century. ...