Researchers studying a series of texts known as the Irish Annals have been able to gauge the impact that volcanic eruptions had on the climate in the Middle Ages. In many cases, eruptions were accompanied by recorded instances of cold weather. "These eruptions occur and they override existing climate patterns for a period of two or three years," said Francis Ludlow of Harvard University. "And it is clear from the sources that they cause a lot of devastation among societies at the time -- whether it was the mass mortality of domestic animals or humans, or indirectly by causing harvest failure."
Published in Brief: