CLIMATE AND CLIMATE CHANGE | Volcanoes: Role in Climate

Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about 1 year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Volcanic eruptions produce global cooling, and are an important natural cause of interdecadal and interannual climate changes. Regional responses include winter warming of Northern Hemisphere (NH) continents following major tropical eruptions and weakening of summer Asian and African monsoons following tropical and NH high latitude eruptions. The volcanic cloud also produces stratospheric ozone depletion. Very large, but rare, eruptions, such as that of Toba 74 000 years ago, may have caused very large climate changes.