evidence: Numerous advances in the field of volcanic effects on climate have been made in the last twenty years despite the absence of a large-magnitude eruption. We now have comprehensive datasets of volcanic SO2, sulfate aerosol and aerosol extinction from ground-based, balloon and satellite measurements (e.g. Carn et al. 2016; Kremser et al. 2016; von Savigny et al. 2020). These data provide much better constraint on volcanic emissions and include daily and near-global observations that show where SO2 and aerosol are dispersed. Improvements in the algorithms used in satellite retrievals have also enabled revised estimates of the emissions of past eruptions, for example those of the 1991 Mt. Pinatubo eruption (Carn 2021; Fisher et al. 2019). A notable advance has been the development of the Global Space-based Stratospheric Aerosol Climatology (GloSSAC) (Kovilakam et al. 2020; Thomason et al. 2018), which is a continuous record of stratospheric aerosol optical properties from 1979 to 2018.