Data from: Differing climatic mechanisms control transient and accumulated vegetation novelty in Europe and eastern North America

To quantify vegetation change and novelty across Europe and eastern North America, we use a selection of sites with standardized age models. Pollen counts are aggregated to 43 types, and are collated into 43 consecutive 500-year-wide age bins, centred on 500-year intervals, from 21 to 0 ka BP. All paleoclimate simulations are from the CCSM3 SynTrace experiments, bias-corrected and downscaled to 0.5° x 0.5° following the methods described by Lorenz et al. (2016). We modelled the predictors of vegetation novelty for the full spatio-temporal dataset, using a linear mixed effects model with the nlme and MuMIn packages in R. Relative variable importance (RVIv) is used to determine the strength of support for a given variable v, as a predictor of vegetation novelty. RVIv is determined by summing the Akaike weights of each variable across all candidate models in which a given variable v, occurs.