Ocean acidification (rescaled raw stressor) 2013 - KNB

Changes in CO2 concentration alter the aragonite saturation state (ASS) of the ocean, among other chemical properties of seawater, and as ASS levels drop the ability of calcifying species such as corals and shelled invertebrates to create calcium carbonate structures declines (S22). The global distribution of ASS values has been modeled at 1- degree resolution for pre-industrial (circa 1870) and modern times (2000-2009) (S23). KNB used the difference between these values as an estimate of the human-derived driver of changes in ocean acidification. Raw stressor data from "Benjamin Halpern, Melanie Frazier, John Potapenko, Kenneth Casey, Kellee Koenig, et al. 2015. Cumulative human impacts: raw stressor data (2008 and 2013). Knowledge Network for Biocomplexity. doi:10.5063/F1S180FS."