Time of Emergence and Large Ensemble Intercomparison for Ocean Biogeochemical Trends

Schlunegger, S., Rodgers, KB, Sarmiento, JL, Ilyina, T., Dunne, JP, Takano, Y., Christian, JR, Long, MC, Frölicher, TL, Slater, R., & Lehner, F. (2020). Time of Emergence and Large Ensemble Intercomparison for Ocean Biogeochemical Trends. Global Biogeochemical Cycles, 34 (8), e2019GB006453. https://doi.org/10.1029/2019GB006453

Summary:

Man‐made climate change is causing physical, chemical, and biological changes in the ocean. In this study the Earth system models (climate models with an interactive carbon cycle) were used to estimate when these man‐made changes will be significantly larger than, and therefore distinguishable from, natural fluctuations in the climate and oceans. The models investigated in this study agreed that changes in sea surface temperature and the strength of the ocean carbon sink should already or will soon be detectable in the current observational record. Changes in the upper ocean biological cycling of carbon, photosynthetic activity, and salinity, however, are less certain and will take many more decades of monitoring in order for man‐made changes to potentially become visible. The authors examined sources of uncertainty inherent to projecting the ocean’s future over the coming decades and found that uncertainty in the ocean’s natural variability can be as important as uncertainty across different climate models and uncertainty in how much carbon humans will emit.