A network of interdisciplinary scholars studying past climate change
An article just published in Geophysical Research Letters and widely picked up by the media argues that the Little Ice Age was triggered by a series of large tropical eruptions in the late 13th and mid-15th centuries and sustained by sea-ice/ocean feedbacks. Lead author Gifford Miller and colleagues traced the abrupt expansion of Canadian ice cover during these events, indicative of summer cooling. Using previous studies of Iceland sea-ice expansion and global circulation models, the authors theorize that expanding ice cover could have cooled the North Atlantic through albedo effects and slowed the Atlantic meridional overturning circulation. The study suggests that even though volcanic dust veils might only last a few years, volcanic activity could have had a more enduring influence on climate. The article concludes that the LIA didn’t need a solar trigger at all — an intriguing but likely controversial assessment.