The rate of global warming has been slower in the past decade than scientists had predicted. Now, some of them are pointing to a possible answer: Volcanoes.
"According to a new study, published in the journal Nature Geoscience, volcanoes are the reason the average rate of warming dropped from .31 degrees Fahrenheit per decade between 1970 and 1998 to .072 degrees Fahrenheit per decade between 1998 and 2012," reports the International Business Times. "This 'muted surface warming' was the result of a series of 17 small volcanic eruptions, beginning in 2000, that spewed enough aerosols into the atmosphere to explain the disparity between climate change models and actual warming trends."
John Abraham, a thermal scientist at the University of St. Thomas, wrote about the theory for the Guardian:
We've known for years that large eruptions can cause a temporary decrease in the Earth temperature but what about small eruptions? The authors found that in the past decade or so, the impacts of volcanoes are found in the optical depth (clarity) of the atmosphere and in temperatures of the lower part of the atmosphere (the troposphere). The authors input the results into computer models and compared the calculations to models that ignored volcanic effects. They discovered that when volcanoes are included, the models were more able to match the observed temperatures.
Abraham sits in this week for Paul Huttner on Climate Cast.