Extended Data Table 3 Summary of results from model simulations
From: Enhanced silica export in a future ocean triggers global diatom decline
- Comparison of global-scale impacts of OA-driven slowdown of opal dissolution versus other climate change impacts in our simulations with the UVic ESCM model, given for the key quantities of our study: Si(OH)4, NO3 as well as biomass of diatoms and small phytoplankton (Phytosmall) in the surface ocean. Shown are temporal changes relative to preindustrial conditions in the standard model (excluding OA-effects on Si dissolution) and the model including OA effects on Si dissolution, as well as the net OA effect given as the difference between the two model configurations (ΔOA, see Methods). Simulated impacts of climate change are consistent with other models, predicting reduced nutrient supply to the surface ocean, owing to enhanced thermal stratification30,31,45, a concomitant long-term nutrient trapping in the deep ocean70, as well as a resulting decline in phytoplankton biomass (mostly diatoms) and shift towards low-nutrient adapted (‘small’) phytoplankton71,72,73. In the simulations including OA effects on Si dissolution, the loss of Si(OH)4 from the surface ocean is strongly amplified, almost doubling the long-term silica trapping in the deep ocean (for example, from −22% to −42% in 2200 under RCP8.5). This additional loss of Si(OH)4 from the surface ocean exacerbates nutrient limitation for diatoms, thereby amplifying their decline under climate change by up to 1.8-fold (for example, from −25% to −45% in 2200 under RCP8.5). See Extended Data Fig. 5 for a visualization of results for Si(OH)4 and diatom biomass.
