Abstract/Summary

Volcanic activity plays a strong role in modulating climate variability (ref. 1). Most model projections of the twenty-first century, however, under-sample future volcanic effects by not representing the range of plausible eruption scenarios (ref. 2,3,4). Here, we explore how sixty possible volcanic futures, consistent with ice-core records (ref. 5), impact climate variability projections of the Norwegian Earth System Model (NorESM) (ref. 6) under RCP4.5 (ref. 7). The inclusion of volcanic forcing enhances climate variability on annual-to-decadal timescales. Although decades with negative global temperature trends become ∼50% more commonplace with volcanic activity, these are unlikely to be able to mitigate long-term anthropogenic warming. Volcanic activity also impacts probabilistic projections of global radiation, sea level, ocean circulation, and sea-ice variability, the local-scale effects of which are detectable when quantifying the time of emergence (ref. 8). These results highlight the importance and feasibility of representing volcanic uncertainty in future climate assessments.