# Robert Berner Back to [[Topics/Climate Change Science and Policy Debate/Climate Change Science and Policy Debate|Climate Change Science and Policy Debate]] · [[Topics/Climate Change Science and Policy Debate/Research and Evidence|Research and Evidence]] **Role:** Geochemist, Yale; built the GEOCARB long-term carbon-cycle models. - Yale geochemist known for the GEOCARB models of Phanerozoic CO₂ ⚠️ (biographical details from memory; he died in 2015 ⚠️). - **Berner & Kothavala 2001, "GEOCARB III: a revised model of atmospheric CO2 over Phanerozoic time"**, *American Journal of Science* 301:182 ([doi](https://doi.org/10.2475/ajs.301.2.182)). It gives CO₂ as RCO₂ (a ratio to pre-industrial) in 10-Myr steps. Cambrian peaks are ~25–26×, the Late Ordovician (440 Ma) ~16.7×, and the Late Carboniferous (300 Ma) ~1.25× (NOAA copy of the data). - This is the source of Eschenbach's CO₂ bars and of the ">4,000 ppm Ordovician glaciation" figure. Proxy-based reconstructions such as PhanDA and Foster et al. 2017 have since revised many Paleozoic values downward. - Appears in: [[Users/@PeterDClack/Post Analyses/Post Analysis - PeterDClack on High-CO2 Epochs and Biodiversity (2026-10-23)|Oct 23 high-CO₂ epochs analysis]].