Quantitative estimation of global mean precipitation throughout the Phanerozoic era

Quantitatively estimating the global mean precipitation (GMP) throughout Earth’s history is crucial for enhancing our understanding of long-term climate evolution and the hydrological cycle. However, currently there is no established methodology for estimating global mean paleoprecipitation. Here, we present the first study that estimates GMP in the Phanerozoic era. The relationship between GMP and global mean surface temperature (GMST) is investigated by analyzing data from 23 models in the Coupled Model Intercomparison Project phase 6 (CMIP6). The result reveals consistent and significant impact of temperature on precipitation, with a sensitivity range of 2–3 % K−1. Additionally, we propose a method for accessing latitudinal variations in precipitation caused by land area distributions and paleo-Köppen climatic belts. These climatic belts are determined based on geological indicators such as coals, evaporites, and glacial deposits. The GMP is thus quantitatively estimated by combining variations in GMST, land area distributions, and paleo-köppen climatic belts, spanning from 540 Ma to the present day. The quantitative GMP curve demonstrates fluctuations in GMP about 500 mm yr−1, with values ranging from 948 to 1442 mm yr−1 over the Phanerozoic era. This curve aligns closely with findings derived from numerical simulations. The presented paleoprecipitation variations facilitate a more comprehensive understanding of the interconnected geological and paleoclimatic developments.