Reconciling inter-hemispheric proxy-model temperature inconsistencies during the past millennium by using tree-ring anatomy

The markedly different reconstructed Northern and Southern Hemispheres (NH, SH) temperature histories over the past millennium are puzzling given the modelled interhemispheric agreement. Resolving whether the hemispheres are differently sensitive to anthropogenic, volcanic and other climate forcing is critical to understand and evaluate the efficacy of climate model projections. Thus, there is an urgent need to explore whether the NH-SH model vs. proxy inconsistencies could be related to spatially imbalanced and/or biased proxy records. We seek to elucidate - by establishing a global network of high-precision tree-ring anatomy data - whether the reconstructed discrepancies in SH-NH temperature history can be reconciled. Our results will place the current climate change in an unprecedentedly precise context and provide a new long-term perspective of the differences and similarities in the NH-SH temperature histories especially considering effects of volcanic eruptions.