Fig. 3.

Conceptual diagram illustrating the main effects of ocean acidification, warming, and their combination on ecosystem processes and species groups, based on the metaanalysis results as shown in the various figures of our study. Circled arrows indicate the direction of change, and question marks (?) indicate less certain responses. The most likely feedback responses that exacerbate the direct effects of these two global stressors are indicated with white arrows. Two model ecosystems are shown here (reefs and surface-ocean) to visually capture potential change [present day (Upper Left and Upper Right) vs. future (Lower Left and Lower Right)] in species abundance, species diversity, and community shifts, as revealed by our metaanalysis for ecosystems in general. The changes shown here for reefs and surface-ocean are not exact outcomes of future states but merely emphasize overall responses for (relative) abundance of species.