Quantifying the impact of volcanic eruptions on climate

Discussion of how scientific researchers progress in learning about how nature works.

http://www.eurekalert.org/pub_releases/2015-08/udg-qti083115.php

Public Release: 31-Aug-2015
Quantifying the impact of volcanic eruptions on climate
Université de Genève

Large volcanic eruptions inject considerable amounts of sulphur in the stratosphere which, once converted into aerosols, block sun rays and tend to cool the surface of the Earth down for several years. An international team of researchers has just developed a method, published in Nature Geoscience, to accurately measure and simulate the induced drop in temperature.

Considered the most important volcanic event of the 20th century, the eruption of Mount Pinatubo (June 1991) injected 20 million tons of sulphur dioxide in the stratosphere and provoked a global cooling of 0.4°C on average.

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For the first time, results provided by reconstructions and climate models about the intensity of cooling converge and demonstrate that the Tampora and Samalas eruptions generated an average drop in temperature in the Northern Hemisphere fluctuating between 0.8 and 1.3°C during the summer 1258 and 1816. Both approaches also agree on the average persistence of the significant cooling which is estimated at two to three years. These results pave the way to a better assessment of the role played by volcanism on climate change.