The map shows estimated aragonite saturation state (an indicator of ocean acidification) for CO2 stabilization levels of 380 ppm, 450 ppm, and 500 ppm, which correspond approximately to the years 2005, 2030, and 2050 under the IPCC A1B (business-as-usual) emissions scenario. Data were adapted from Cao, L. and K. Caldeira. 2008. “Atmospheric CO2 Stabilization and Ocean Acidification.” Geophysical Research Letters 35: L19609 for use in the Reefs at Risk Revisited project.