# Gavin Foster 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:** Isotope geochemist, University of Southampton; Phanerozoic CO₂ and climate forcing. - Professor of isotope geochemistry, University of Southampton ⚠️ (title from memory). - **Foster, Royer & Lunt 2017, "Future climate forcing potentially without precedent in the last 420 million years"**, *Nature Communications* 8:14845 ([doi](https://doi.org/10.1038/ncomms14845)). It compiles proxy CO₂ for 420 Myr and shows that falling CO₂ roughly offset the Sun's slow brightening, which added ~+9 W/m² of forcing ⚠️ (value from the earlier session notes). It concludes that continued emissions could produce forcing without precedent in 420 Myr. - Relevance: high Paleozoic CO₂ is not equivalent to the same CO₂ today, because the Sun was fainter. - Appears in: [[Users/@PeterDClack/Post Analyses/Post Analysis - PeterDClack on High-CO2 Epochs and Biodiversity (2026-10-23)|Oct 23 high-CO₂ epochs analysis]].