Boron Isotopes Provide Insights into Biomineralization, Seawater pH, and Ancient Atmospheric CO2

Abstract

Rising atmospheric CO 2 and falling ocean pH place an urgency on our efforts to understand the impact of CO 2 on Earth's ecosystems and climate Studies of past perturbations of Earth's carbon reservoirs and climate-ranging from glacialinterglacial cycles to mass extinction events-may provide valuable insights, but they require the ability to reconstruct changes in ocean-atmosphere CO 2 chemistry in Earth's past. Here, we provide an overview of the boron isotope pH proxy in marine carbonates and how it can be applied to reconstruct past ocean pH and atmospheric CO 2 .