There is a substantial body of research showing that a combination of ocean acidification and elevated ocean temperature have a compounded effect on marine life and the ocean environment. This effect far exceeds the individual harmful impact of either. In addition, ocean warming, along with increased productivity of phytoplankton from higher CO levels exacerbates ocean deoxygenation. Deoxygenation of ocean waters is an additional stressor on marine organisms that increases ocean stratification therefore limiting nutrients over time and reducing biological gradients. 
Meta analyses have quantified the direction and magnitude of the harmful effects of combined ocean acidification, warming and deoxygenation on the ocean. These meta-analyses have been further tested by mesocosm studies that simulated the interaction of these stressors and found a catastrophic effect on the marine food web: thermal stress more than negates any primary producer to herbivore increase in productivity from elevated .