Estimating Summer Arctic Warming Amplitude Relative to Pre-Industrial Levels Using Tree Rings

Estimating long-term trends and short-term amplitudes requires reliable temperature (Temp) observations in the pre-industrial period when few situ existed Arctic. Tree-ring materials are most available used to reconstruct past Arctic Temp variations. However, previous studies incorporated that insensitive local variabilities. The derived reconstruction qualities low (indicated by calibration R2), uncertainties inherent various detrending methodologies unknown. To (N60°–N90°) summer (June–August) 1850–1900 variations over centuries, we screened 1116 tree-ring width density records applied four functions (sf-RCS, RCS, MOD, spline). In total, 338–396 show significant correlations (p < 0.05) with Climate Research Unit (CRU) of corresponding grid point. These were selected combined into a proxy record. achieved explained 45–57% instrumental variance since 1950. 2012–2021 warming (1.42–1.74 °C) estimated anomaly datasets extending back 1850 within range from our reconstructions, despite using methods. findings could suggest Berkeley HadCRU5 interpolating (6–73) meteorological stations still represent mean variation 1850–1900, updated can be as reference for 1550–2007 history.