Volcanic Eruption in Iceland Triggered Colder Winters

ICELAND -- A huge volcanic eruption that took place sometime between 1983 to 1984 brought about an unusual effect. Instead of an intense heat wave during the summer season, it may have triggered colder winters. The findings of the research will be published in the Journal of Geophysical Research: Atmosphere and it aims to help geologists and other scientists to improve their predictions as to how the climate, especially those in high latitudes, respond to volcanic eruptions.

The eruption of the Laki Volcano in Iceland lasted for eight months beginning in June of 1983 to early 1984. It was one of the largest volcanic eruptions in a high-altitude area in the last century. The eruption also released six times more sulfur dioxide in the upper atmosphere than the eruption of Krakatau in 1983 and Pinatubo in the Philippines in 1991.

"The eruption was definitely big that it brought with it a massive release of dangerous substances in the atmosphere," says Alan Robock, co-author of the study and a professor in Environmental Science Department of Rutgers University.

The experts, back then, predicted that the country will experience a warmer summer as they expected the volcanic eruption to contribute to warming up the area. Although it did get the temperature 5 degrees higher than usual and caused societal disruptions, not to mention failed harvests, it also triggered colder winter months where temperatures were lowered by 5 degrees as well.

Benjamin Franklin, a US ambassador to Europe back then, was the first who looked into the effects of volcanic eruptions on the climate. He published his results in a paper in 1784. To determine whether his predictions were true, the researchers performed 80 varying simulations using a state-of-the-art climate model.

"The results turned out as a surprise because it showed that the warmer weather during the summer was not caused by the eruption," stated Robock. "Instead, it can be considered as a natural variability present in the climate. However, the simulations also show that the colder winter seasons should have been expected after the eruption."

More than 50% of Iceland's livestock died within the year since the eruption of the Laki Volcano and there was a 20% recorded increase in human deaths due to respiratory failures and famine. Experts pointed out that the report on the increase in deaths among humans, animals, and plants, should have been enough reason to look into the harsher effects of volcanic eruptions in general.

"Understanding what causes these climate anomalies plays a significant role not only in history but also in economics and health. When we understand how the climate reacts to volcanic eruptions, it is easier for us to make predictions that will help people do what they need to do to prepare," says Robock.