Finding the Fingerprint of Anthropogenic Climate Change in Marine Phytoplankton Abundance

Abstract

We review how phytoplankton abundance may be responding to the increase in stratification associated with anthropogenic climate change, providing context on the utility of remote sensing datasets and Earth system model output to understand these perturbations. Assessing disruption in the ocean biosphere using remote sensing datasets is challenged by the relatively short length of the observational record, restricting our ability to disentangle fluctuations due to internal climate variability from those imposed by externally forced anthropogenic trends. Ensembles of Earth system models can be used to quantify past and future drivers, but may not skillfully predict observed spatial patterns and temporal dynamics in marine phytoplankton. To better understand the role of internal climate variability in the observational record, we construct a synthetic ensemble of global chlorophyll concentration over the MODIS satellite mission using statistical emulation techniques. We emphasize the use of a synthetic ensemble to illuminate the role of internal climate variability in the evolution of the ocean biosphere over time.