The Boreal and Austral volcanic cooling conundrum

Climate modelling of the past millennium shows substantial volcanic cooling in both Southern and the Northern Hemispheres (SH; NH).

Tree-rings is the only natural paleoclimate proxy archive capable to detect volcanic climate responses over the Common Era but is currently only able to corroborate this in the NH.

Here we aim to resolve this NH-SH volcanic cooling inconsistency using the promising and exceptionally precise method of tree-anatomy.

The project will run over four years (2025-2028) and the P.I. will compile wood samples and existing tree-ring anatomy data from participating researchers around the world to analyze and put together a global and inter-hemispherically representative network. Key data production steps will be purchased from a partner institute in Switzerland.

The diversely experienced participating researchers are foremost data and sample providers.

They will also act as an advisory board for study designs and manuscript drafting, specifically comparing reconstructed SH and NH volcanic responses, and ultimately help to create a global volcanic cooling atlas for the most prominent eruptions of the Common Era.

Episodic volcanic forcing represents examples of radiative and dynamical atmospheric processes triggering responses in the climate system.

Validated volcanic climate responses by proxy records would confirm sound physics in climate models and be instrumental in constraining modelled scenarios of future climate change.