Climate cooling effect of volcanoes is bigger than we thought

Analysis of sulphate particles in a Greenland ice core suggests we have underestimated the impact of volcanoes, and overestimated the contribution of anthropogenic sources

By Kate Ravilious

Volcanoes are emitting up to three times more climate-cooling gases than previously thought, according to an analysis of tiny particles in a Greenland ice core.

Sulphate aerosols have a cooling effect on the climate by altering clouds and reflecting solar radiation. Gases released by volcanoes, marine phytoplankton and the burning of fossil fuels all contribute to the production of sulphate aerosols, but measuring the contribution from each source is very hard, so there is uncertainty about their climate impact.

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