VICS - Volcanic Impacts on Climate and Society



The VICS working group supports research focused on reconstructing the history of past explosive volcanism, in addition to research utilizing this knowledge to better understand how the climate system responds to changes in radiative forcing, and how societies have been impacted by and responded to the resulting climatic shocks.

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- Improve and extend reconstructions of past volcanic eruptions and their associated regional and global radiative impacts from a variety of proxy sources.
- Advance physical understanding of different components of the climate system through analysis of their responses to volcanic forcing as recorded in climate proxies and simulated by climate models.
- Support investigation of the response of societies to sudden climate shocks resulting from volcanic eruptions.


Matthew Toohey (Group Lead and Mailing List Administrator) GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
Michael Sigl, Paul Scherrer Institut, Switzerland
Kevin Anchukaitis, University of Arizona, USA
Allegra N. LeGrande, NASA Goddard Institute for Space Studies, USA
Francis Ludlow, Yale Climate & Energy Institute, and Department of History, USA
Celine Vidal, University of Cambridge, UK


Oct 2015
 0124-0610-2618-0801 view from space showing the eruption of cleveland volcano aleutian islands alaska m

Figure 1: Eruption of Cleveland Volcano, Aleutian Islands, Alaska, photographed by an Expedition 13 crew member on the International Space Station, NASA. This image, acquired shortly after the beginning of the eruption, captures the ash plume moving west-southwest from the summit vent. Credit: Stock Photo by NASA Public Domain - ISS013-E-24184 (23 May 2006).

Radiative forcing resulting from stratospheric aerosols produced by major volcanic eruptions is a dominant driver of climate variability in the Earth’s past. Accurate knowledge of the climate anomalies resulting from volcanic eruptions provides important information for understanding the global and regional responses of the Earth system to external forcing agents, including anthropogenic greenhouse gases. It also offers the opportunity to improve our understanding of the relationship between climate and society, using abrupt volcanically-triggered climatic shocks as test-cases of societal impact and response.

Proxy-based climate reconstructions spanning recent centuries clearly show the short-term influence of a number of volcanic events (Masson-Delmotte et al. 2013). It has also been suggested that volcanic forcing plays a role in climate variability on multi-decadal scales through complex feedback mechanisms or the compounded impact of multiple closely-spaced eruptions (Crowley 2000). However, recent works have highlighted apparent mismatches between proxy-based climate reconstructions and climate model simulations using previously reconstructed time-series of volcanic forcing (Mann et al. 2012; Anchukaitis et al. 2012). These studies highlight the need for a deeper understanding of the information contained in proxy records, and improved knowledge of the characteristics of past volcanic radiative forcing.

VICS aims to foster interdisciplinary activities towards better understanding of the impacts of volcanic forcing on climate and societies. VICS will support the development of next-generation volcanic forcing histories, initially covering the past 2,000 years and eventually extending to the full Holocene.

These forcing data sets will be provided to the climate modeling community, and VICS will support efforts to validate model results through comparison with instrumental, proxy, and documentary climate information of post-volcanic climate anomalies.

Improved volcanic forcing reconstructions, and multi-model experiments will form the basis for producing improved quantitative estimates of the varied impacts of volcanic eruptions on the climate system, as well as on past, present, and future societies.

Key aims

VICS aims to provide a forum for the exchange of information between different communities interested in the impacts of volcanic eruptions, including communities involved in paleoclimate reconstruction, climate modeling, ice core interpretation, and historical climate/societal interactions.

VICS has three overarching scientific aims:

1. Improve volcanic radiative forcing reconstructions:
Knowledge of the history of volcanic forcing is becoming clearer and clearer thanks to analysis of ice cores from Antarctica and Greenland. VICS will support the reconstruction of next-generation volcanic forcing data sets—focusing first on the past 2000 years, and eventually the full Holocene—and facilitate their use within modeling efforts such as the Paleo-Modelling Intercomparison Project (PMIP). VICS will also support work on improving the accuracy of volcanic forcing, through reducing uncertainties in the relationship between stratospheric aerosol loading and deposition to the polar ice sheets.

2. Improve understanding of volcanically-induced climate variability:
Climate models, proxy-based climate reconstructions and instrumental data don’t always agree on the climate impact of major volcanic eruptions of the past. VICS will support efforts to improve agreement between different sources of information, fostering collaboration between the proxy, cryosphere, and climate modeling communities, for example concerning the validation of simulations performed within the PMIP and VolMIP projects. Special emphasis will be placed on the regional and seasonal character of volcanic responses and proxy records, the robustness of decadal-scale responses, dynamical responses linked to atmospheric circulation (e.g. changes in precipitation), the role of different boundary conditions (e.g. season and ocean state), and the roles of eruption frequency versus magnitude. Model experiments will make a valuable contribution to exploring physical mechanisms linking volcanic emissions with different climate responses.

3. Improve understanding of societal impacts of volcanic eruptions:
VICS will encourage studies into how major eruptions have impacted societies in the past, on different timescales (short-term to longer-term) and in a range of different socioeconomic and cultural settings expected to have varying susceptibility to volcanically-induced climatic shocks. This will be based on examination of historical and archeological records, and will also aim to develop tools to better frame climate model results in terms of societal impacts. Such tools will be helpful in predicting societal impacts of major near-future eruptions, e.g. how a Pinatubo or Tambora-magnitude eruption might impact modern economies.

Learn more and participate

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This group is open to anyone who is interested. To participate, please contact a member of the Steering Group.