Alexandria, VA – Volcanism is often implicated in periods of abrupt cooling. After the 1991 eruption of Mount Pinatubo in the Philippines, for instance, global temperatures dropped by half a degree Celsius due to airborne particulate matter blocking solar radiation. However, these effects don't normally last more than a few years. Yet, a recent study blames volcanism for a 500-year cold period referred to as the Little Ice Age.

Beginning around the end of the Middle Ages and lasting into the early 19th century, unusually cold conditions blanketed much of the Northern Hemisphere. This period is known as the Little Ice Age. When exactly this period began, and how it was sustained for so long are matters of much debate. The culprit, according to a new study put forth by climate scientist Gifford Miller of the University of Colorado, is volcanism. How can a short-lived event like a volcanic eruption trigger cooling that lasts for centuries? Find out at http://www.earthmagazine.org/article/volcanoes-sparked-and-prolonged-little-ice-age.