Volcanic geochemical signatures at Page-Ladson, Florida support volcanic forcing as a contributing trigger of the Younger Dryas cooling.

Abbott et al. 2021: a cluster of large eruptions just before the cooling

what the source states

Using synchronised sulphate and sulphur records from Greenland and Antarctic ice cores for 13,200 to 12,800 years before 1950, the authors write that their reconstruction "highlights a ~110-year cluster of four major bipolar volcanic signals alongside several smaller events just prior to the YD inception," that "The cumulative Northern Hemisphere aerosol burden and radiative forcing from this cluster exceeds the most volcanically active periods during the Common Era," and that this "highlights the need to consider stratospheric sulphur injections and their radiative forcing in future analyses and climate model experiments."

what we infer

The volcanic candidate's ice-core basis: the eruptions are measured in both hemispheres' ice and sit at the right moment, unlike the Greenland platinum. That makes volcanic forcing a trigger candidate with an observed, correctly timed forcing behind it — something neither the meltwater account nor the impact account has in the same ice. It is a timed forcing, not a demonstrated cause.

limitations

• Shows the forcing occurred; whether it could tip the deglacial climate into the Younger Dryas is left to model experiments the paper calls for, not demonstrated.
• Comparable eruptions occur elsewhere in the glacial record: Green et al. 2025, citing a 2022 catalogue of 1,113 eruptions in Greenland cores, rank the eruptions at 12,978 and ~12,870 yr BP 16th and 17th by sulphur released. Coincidence in time is not causation.
• The eruptions' sources are unidentified; the paper's tentative Laacher See candidates sit a century before the onset.