Volcanic eruptions impact climate through the injection of large amounts of ash and sulfur gas into the atmosphere (Fig. 1a). This gas is converted to sulfate aerosols, which reflect solar radiation in the stratosphere, decreasing the amount of solar radiation reaching the Earth's surface. The primary result is a cooling of the Earth's surface. Volcanic sulfate is mixed and transported within the stratosphere, and eventually travels downward into the troposphere, where it is finally deposited to the surface of the Earth. Sulfate deposition over the ice sheets is preserved in annually accumulating ice layers , allowing for reconstruction of the magnitude and timing of past volcanic events with the help of ice cores (Fig. 1b-d). The impact of volcanic eruptions is also clearly seen in other paleoclimate records. Temperature reconstructions predominantly obtained from tree-ring chronologies (Fig. 1e,f; Fig. 2) spanning previous centuries show the influence of a number of volcanic events (D'Arrigo et al. 2001; PAGES2k consortium 2013; Salzer et al. 2014); however, a number of apparent mismatches between paleoclimate reconstructions and previously reconstructed volcanic forcing records have been noted (e.g. Mann et al. 2012). Striving towards better agreement between proxy-based climate reconstructions and model simulations is an important component of current climate research (Toohey et al. 2013). The paleoclimate record – i.e. reconstructions of past climate variables such as temperature and precipitation, produced from analysis of proxies such as tree rings, ice cores, and marine sediments – is essential for understanding the Earth system's response to various forcing agents. Sulfate measurements in ice cores because a major driver of climate variability over the past centuries is the impact of volcanic eruptions, the ability of climate model simulations to accurately recreate past climate is tied directly to the accuracy of the volcanic forcing time series used in the simulations. Presently, all volcanic forcing estimates used in paleoclimate model simulations is derived from ice cores. Time series of sulfate deposition from ice cores are translated into estimates of atmospheric sulfate aerosol loading, and corresponding estimates of radiative forcing. Volcanic forcing sets typically used in modern paleo-climate simulations span the years 500/800-2000 cE (crowley and Unterman 2013; Gao et al. 2008), although the limited number of ice cores used to derive the forcing in the early years of the data set limits the accuracy of the estimated forcing (Sigl et al. 2014). The limited number of records currently included in volcanic forcing …