PaleoJump: A database for abrupt transitions in past climates

Tipping points (TPs) in the Earth system have been studied with growing interest and concern in recent years due to the potential risk of anthropogenic forcing causing abrupt, and possibly irreversible, climate transitions. Paleoclimate records are essential for identifying TPs in Earth's past and for properly understanding the climate system's underlying nonlinearities and bifurcation mechanisms. Due to the variations in quality, resolution, and dating methods, it is crucial to select the records that give the best representation of past climates. Furthermore, as paleoclimate time series vary in their origin, time spans, and periodicities, an objective, automated methodology is crucial for identifying and comparing TPs. To reach this goal, we present here the PaleoJump database of carefully selected, high-resolution records originating in ice cores, marine sediments, speleothems, terrestrial records, and lake sediments. These records describe climate variability on centennial, millennial, or longer time scales and cover all the continents and ocean basins. We provide an overview of their spatial distribution and discuss the gaps in coverage. Our statistical methodology includes an augmented Kolmogorov-Smirnov test and Recurrence Quantification Analysis; it is applied here to selected records to automatically detect abrupt transitions therein and to investigate the presence of potential tipping elements. These transitions are shown in the PaleoJump database together with other essential information, including location, temporal scale and resolution, along with temporal plots. This database represents, therefore, a valuable resource for researchers investigating TPs in past climates.